Lanthanide complexes containing 5-methyl-1,2,4-triazolo[1,5-a] pyrimidin-7(4H)-one and their therapeutic potential to fight leishmaniasis and Chagas disease.
ría-Díaz N, Gutiérrez-Sánchez R Abstract In the last years, numerous and significant advances in lanthanide coordination chemistry have been achieved. The unique chemical nature of these metal ions which is conferred by their f-electrons has led to a wide range of coordination compounds with interesting structural, physical and also biological properties. Consequently, lanthanide complexes have found applications mainly in catalysis, gas adsorption, photochemistry and as diagnostic tools. However, research on their therapeutic potential and the understanding of their mechanism of action...
Source: Journal of Inorganic Biochemistry - May 6, 2014 Category: Biochemistry Authors: Caballero AB, Rodríguez-Diéguez A, Salas JM, Sánchez-Moreno M, Marín C, Ramírez-Macías I, Santamaría-Díaz N, Gutiérrez-Sánchez R Tags: J Inorg Biochem Source Type: research

Rat liver antioxidant response to iron and copper overloads.
Repetto MG Abstract The rat liver antioxidant response to Fe and Cu overloads (0-60mg/kg) was studied. Dose- and time-responses were determined and summarized by t1/2 and C50, the time and the liver metal content for half maximal oxidative responses. Liver GSH (reduced glutathione) and GSSG (glutathione disulfide) were determined. The GSH content and the GSH/GSSG ratio markedly decreased after Fe (58-66%) and Cu (79-81%) loads, with t1/2 of 4.0 and 2.0h. The C50 were in a similar range for all the indicators (110-124μgFe/g and 40-50μgCu/g) and suggest a unique free-radical mediated process. Hydrophilic anti...
Source: Journal of Inorganic Biochemistry - April 30, 2014 Category: Biochemistry Authors: Musacco-Sebio R, Saporito-Magriñá C, Semprine J, Torti H, Ferrarotti N, Castro-Parodi M, Damiano A, Boveris A, Repetto MG Tags: J Inorg Biochem Source Type: research

Comparative thermal and thermodynamic study of DNA chemically modified with antitumor drug cisplatin and its inactive analog transplatin.
Abstract Antitumor activity of cisplatin is exerted by covalent binding to DNA. For comparison, studies of cisplatin-DNA complexes often employ the very similar but inactive transplatin. In this work, thermal and thermodynamic properties of DNA complexes with these compounds were studied using differential scanning calorimetry (DSC) and computer modeling. DSC demonstrates that cisplatin decreases thermal stability (melting temperature, Tm) of long DNA, and transplatin increases it. At the same time, both compounds decrease the enthalpy and entropy of the helix-coil transition, and the impact of transplatin is much...
Source: Journal of Inorganic Biochemistry - April 29, 2014 Category: Biochemistry Authors: Lando DY, Chang CL, Fridman AS, Grigoryan IE, Galyuk EN, Hsueh YW, Hu CK Tags: J Inorg Biochem Source Type: research

Proton and gallium(III) binding properties of a biologically active salicylidene acylhydrazide.
This study addresses this issue by resolving the equilibrium speciation of hydrazone-gallium aqueous solutions. The protonation constants of the target 2-oxo-2-[N-(2,4,6-trihydroxy-benzylidene)-hydrazino]-acetamide (ME0163) hydrazone species and of its 2,4,6-trihydroxybenzaldehyde and oxamic acid hydrazide building blocks were determined by UV-visible spectrophotometry to achieve this goal. These studies show that the hydrazone is an excessively strong complexing agent for gallium and that its antivirulence properties are predominantly ascribed to monomeric 1:1Ga-ME0163 complexes of various Ga hydrolysis and ME0163 protona...
Source: Journal of Inorganic Biochemistry - April 29, 2014 Category: Biochemistry Authors: Hakobyan S, Boily JF, Ramstedt M Tags: J Inorg Biochem Source Type: research

Effect of structure and composition of nickel(II) complexes with salicylidene Schiff base ligands on their DNA/protein interaction and cytotoxicity.
Abstract Three new salicylidene Schiff base nickel(II) complexes [Ni(L(1))(CH3COOH)2]2 (1), [Ni2(L(1))2(CH3OH)] (2), [Ni(L(2))2]·3H2O (3) {H2L(1)=N,N'-bis(salicylidene)-3,6-dioxa-1,8-diaminooctane, HL(2)=2-ethyl-2-(2-hydroxybenzylideneamino)propane-1,3-diol} were synthesized and characterized fully by structural, analytical, and spectral methods. The single-crystal X-ray structures of complexes 1 and 2 exhibit the symmetrical ligands coordinated to the nickel(II) ion in a tetradentate fashion via ONNO donor atoms, while the unsymmetrical ligand L(2) presented a ONO tridentate coordination mode in complex 3....
Source: Journal of Inorganic Biochemistry - April 26, 2014 Category: Biochemistry Authors: Li P, Niu M, Hong M, Cheng S, Dou J Tags: J Inorg Biochem Source Type: research

The gallium(III)-salicylidene acylhydrazide complex shows synergistic anti-biofilm effect and inhibits toxin production by Pseudomonas aeruginosa.
This study investigates synergy effects between Ga(III) ions, previously reported to suppress biofilm formation and growth in bacteria, and salicylidene acylhydrazides (hydrazones) that have been proposed as antivirulence drugs targeting the type three secretion system used by several Gram-negative pathogens, including Pseudomonas aerugionosa, during bacterial infection of host cells. A library of hydrazones was screened for: Fe(III) binding, enhanced anti-biofilm effect with Ga(III) on P. aeruginosa, and low cytotoxicity to mammalian cells. The metal coordination for the most promising ligand, 2-Oxo-2-[N-(2,4,6-trihydroxy...
Source: Journal of Inorganic Biochemistry - April 23, 2014 Category: Biochemistry Authors: Rzhepishevska O, Hakobyan S, Ekstrand-Hammarström B, Nygren Y, Karlsson T, Bucht A, Elofsson M, Boily JF, Ramstedt M Tags: J Inorg Biochem Source Type: research

Inductively coupled plasma mass spectrometry for metallodrug development: Albumin binding and serum distribution of cytotoxic cis- and trans-isomeric platinum(II) complexes.
Abstract Binding to plasma proteins is one of the major metabolic pathways of metallodrugs. In the case of platinum-based anticancer drugs, it is the interaction with serum albumin that affects most strongly their in vivo behavior. Since both the configuration, i.e. cis-trans-isomerism, and the nature of leaving groups have an effect on the reactivity of Pt(II) coordination compounds toward biomolecules, a set of cis- and trans-configured complexes with halide leaving groups (Cl(-), Br(-), and I(-)) and 2-propanone oxime as carrier ligands was chosen for this study. Binding experiments were performed both with alb...
Source: Journal of Inorganic Biochemistry - April 22, 2014 Category: Biochemistry Authors: Ossipov K, Scaffidi-Domianello YY, Seregina IF, Galanski M, Keppler BK, Timerbaev AR, Bolshov MA Tags: J Inorg Biochem Source Type: research

The cytotoxicity of the anticancer drug elesclomol is due to oxidative stress indirectly mediated through its complex with Cu(II).
In conclusion, these results showed that elesclomol indirectly inhibited cancer cell growth through Cu(II)-mediated oxidative stress. PMID: 24798374 [PubMed - as supplied by publisher] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - April 16, 2014 Category: Biochemistry Authors: Hasinoff BB, Yadav AA, Patel D, Wu X Tags: J Inorg Biochem Source Type: research

A platinum(II) complex of liriodenine from traditional Chinese medicine (TCM): Cell cycle arrest, cell apoptosis induction and telomerase inhibition activity via G-quadruplex DNA stabilization.
In this study, complex 1 was further discussed for its antitumor mechanism and structure-activity relationship, comparing with L and cisplatin. Towards the most sensitive BEL-7404 human hepatoma cells, complex 1 significantly induced cell cycle arrest at both G2/M phase and S phase. It suggests that double helix DNA is not the simplex intracellular target for 1. On the other hand, the BEL-7404 cells incubated with 1 and stained by Hoechst 33258 and AO/EB showed typical cell apoptosis in dose-dependent manner. The BEL-7404 cells incubated with 1 and stained by JC-1 were also characteristic for cell apoptosis on the loss of ...
Source: Journal of Inorganic Biochemistry - April 13, 2014 Category: Biochemistry Authors: Li YL, Qin QP, Liu YC, Chen ZF, Liang H Tags: J Inorg Biochem Source Type: research

Spin equilibrium and O2-binding kinetics of Mycobacterium tuberculosis CYP51 with mutations in the histidine-threonine dyad.
Abstract The acidic residues of the "acid-alcohol pair" in CYP51 enzymes are uniformly replaced with histidine. Herein, we adopt the Mycobacterium tuberculosis (mt) enzyme as a model system to investigate these residues' roles in finely tuning the heme conformation, iron spin state, and formation and decay of the oxyferrous enzyme. Properties of the mtCYP51 and the T260A, T260V, and H259A mutants were interrogated using UV-Vis and resonance Raman spectroscopies. Evidence supports that these mutations induce comprehensive changes in the heme environment. The heme iron spin states are differentially sensit...
Source: Journal of Inorganic Biochemistry - April 12, 2014 Category: Biochemistry Authors: Jennings GK, Modi A, Elenewski JE, Ritchie CM, Nguyen T, Ellis KC, C Hackett J Tags: J Inorg Biochem Source Type: research

Synthesis, characterization, crystal structures and biological activity of set of Cu(II) benzothiazole complexes: Artificial nucleases with cytotoxic activities.
Abstract A series of Cu(II) complexes with ligand frames based on quinoline derivatives appended with a benzothiazole substituent has been isolated. The complexes, Cu(Q(oBt))(NO3)2(H2O)∙CH3OH (1∙CH3OH), Cu(8OHQ(oBt))Cl2∙CH3OH (2∙CH3OH), Cu(8OQ(oBt))Cl(CH3OH)∙CH3OH (3∙CH3OH) and [Cu(8OH1/2Q(oBt))(CH3OH)(NO3)]2(NO3) (4) have been characterized by single crystal X-ray diffraction, IR and UV-visible spectroscopies, and elemental analysis. The ligand frame within the set of complexes differs in the substituent on the quinoline ring: complex 1 remains unsubstituted at this position while complexes 2-4 have a...
Source: Journal of Inorganic Biochemistry - April 12, 2014 Category: Biochemistry Authors: Steiner RA, Foreman D, Lin HX, Carney BK, Fox KM, Cassimeris L, Tanski JM, Tyler LA Tags: J Inorg Biochem Source Type: research

Selective hydrolysis of hen egg white lysozyme at Asp-X peptide bonds promoted by oxomolybdate.
Abstract The activity of oxomolybdate(VI) towards hen egg white lysozyme (HEWL) was examined under physiological and slightly acidic pH conditions. Purely hydrolytic cleavage of HEWL in the presence of 10 to 100mM of oxomolybdate(VI) after incubation at pH5.0 and 60°C for 2 to 7days was observed in SDS-PAGE experiments. Four cleavage sites, which all occurred at Asp-X sequences and included the Asp18-Asn19, Asp48-Gly49, Asp52-Trp53 and Asp101-Gly102 peptide bonds, were identified with Edman degradation. The molecular interaction between [MoO4](2-) and HEWL was studied by circular dichroism (CD) and (1)H-(15)N ...
Source: Journal of Inorganic Biochemistry - April 12, 2014 Category: Biochemistry Authors: Stroobants K, Ho PH, Moelants E, Proost P, Parac-Vogt TN Tags: J Inorg Biochem Source Type: research

Anion inhibition studies of two α-carbonic anhydrases from Lotus japonicus, LjCAA1 and LjCAA2.
Anion inhibition studies of two α-carbonic anhydrases from Lotus japonicus, LjCAA1 and LjCAA2. J Inorg Biochem. 2014 Apr 8;136C:67-72 Authors: Vullo D, Flemetakis E, Scozzafava A, Capasso C, Supuran CT Abstract The model organism for the investigation of symbiotic nitrogen fixation in legumes Lotus japonicus encodes two carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the α-class, LjCAA1 and LjCAA2. Here we report the kinetic characterization and inhibition of these two CAs with inorganic and complex anions and other molecules interacting with zinc proteins, such as sulfamide, sulfamic a...
Source: Journal of Inorganic Biochemistry - April 8, 2014 Category: Biochemistry Authors: Vullo D, Flemetakis E, Scozzafava A, Capasso C, Supuran CT Tags: J Inorg Biochem Source Type: research

Effects of Mn-doping on the structure and biological properties of β-tricalcium phosphate.
Effects of Mn-doping on the structure and biological properties of β-tricalcium phosphate. J Inorg Biochem. 2014 Apr 3;136C:57-66 Authors: Torres PM, Vieira SI, Cerqueira AR, Pina S, da Cruz Silva OA, Abrantes JC, Ferreira JM Abstract Doping calcium phosphates with trace elements that exist in bone tissues is beneficial in terms of cell-material interactions and in vivo performance of the bone grafts made thereof. Manganese (Mn) is an essential element for normal growth and metabolism of bone tissues, but studies reporting the effects of Mn-doping calcium phosphates are scarce. The present study ...
Source: Journal of Inorganic Biochemistry - April 3, 2014 Category: Biochemistry Authors: Torres PM, Vieira SI, Cerqueira AR, Pina S, da Cruz Silva OA, Abrantes JC, Ferreira JM Tags: J Inorg Biochem Source Type: research

Dilution of dipolar interactions in a spin-labeled, multimeric metalloenzyme for DEER studies.
In this study, we prepared a site-specific, double spin-labeled analog of homotetrameric MβL L1 with spin labels at positions 163 and 286 and analyzed the sample with DEER (double electron electron resonance) spectroscopy. Four unique distances were observed in the DEER distance distribution, and these distances were assigned to the desired intramolecular dipolar coupling (between spin labels at positions 163 and 286 in one subunit) and to intermolecular dipolar couplings. To rid the spin-labeled analog of L1 of the intermolecular couplings, spin-labeled L1 was "diluted" by unfolding/refolding the spin-label...
Source: Journal of Inorganic Biochemistry - April 1, 2014 Category: Biochemistry Authors: Aitha M, Richmond TK, Hu Z, Hetrick A, Reese R, Gunther A, McCarrick R, Bennett B, Crowder MW Tags: J Inorg Biochem Source Type: research

Preface: Gas and redox sensors special issue.
PMID: 24629328 [PubMed - in process] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - March 21, 2014 Category: Biochemistry Authors: Knapp MJ Tags: J Inorg Biochem Source Type: research

Disulfide bonds regulate binding of exogenous ligand to human cytoglobin.
In this study, we measured cyanide binding to the ferric state of the wild-type (WT) Cgb, and found that the binding consisted of multiple steps. These results indicated that Cgb may be comprised of several forms, and the presence of monomers, dimers, and tetramers was subsequently confirmed by SDS-PAGE. Remarkably, each species contained two distinguishable forms, and, in the monomer, analyses of alternative cysteine states suggested the presence of an intramolecular disulfide bond (monomer SS form) and a structure with unpaired thiol groups (monomer SH form). These confirmed that forms were separated by gel-exclusion chr...
Source: Journal of Inorganic Biochemistry - March 1, 2014 Category: Biochemistry Authors: Tsujino H, Yamashita T, Nose A, Kukino K, Sawai H, Shiro Y, Uno T Tags: J Inorg Biochem Source Type: research

Preface for the JIB Special Issue on Latin American Bioinorganic Chemistry.
Authors: PMID: 24549107 [PubMed - in process] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - February 20, 2014 Category: Biochemistry Tags: J Inorg Biochem Source Type: research

Differential effects of aluminum on in vitro primary root growth, nutrient content and phospholipase C activity in coffee seedlings (Coffea arabica).
resa Hernández Sotomayor SM, Estévez MM Abstract Coffea arabica is a woody species that grows in acid soils, where aluminum is available and may affect growth and productivity. To determine the effect of aluminum on primary root growth of C. arabica cv. Typica, seedlings were exposed over 30days to different concentrations of AlCl3 (0, 100, 300 and 500μM) in vitro. The aluminum effect on primary root growth was dose-dependent: low aluminum concentrations (100 and 300μM) stimulated primary root growth (6.98±0.15 and 6.45±0.17cm, respectively) compared to the control (0μM; 5.24&p...
Source: Journal of Inorganic Biochemistry - February 3, 2014 Category: Biochemistry Authors: de A Bojórquez-Quintal JE, Sánchez-Cach LA, Ku-González A, de Los Santos-Briones C, de Fátima Medina-Lara M, Echevarría-Machado I, Muñoz-Sánchez JA, Teresa Hernández Sotomayor SM, Estévez MM Tags: J Inorg Biochem Source Type: research

Cytotoxicity of cyclometalated platinum complexes based on tridentate NCN and CNN-coordinating ligands: Remarkable coordination dependence.
Abstract A series of cyclometalated platinum complexes with diverse coordination patterns and geometries were screened for their anticancer activity. It was discovered that the N^C^N-coordinated platinum complex based on 1,3-di(pyridyl)benzene displayed much higher cytotoxicity against human lung cancer cells NCI-H522, HCC827, and NCI-H1299, and human prostate cancer cell RV1 than cisplatin. In a sharp contrast, the C^N^N-coordinated platinum complex based on 6-phenyl-2,2'-bipyridine was ineffective on these cancer cells. This remarkable difference in cytotoxicity displayed by N^C^N- and C^N^N-coordinated platinum...
Source: Journal of Inorganic Biochemistry - February 3, 2014 Category: Biochemistry Authors: Vezzu DA, Lu Q, Chen YH, Huo S Tags: J Inorg Biochem Source Type: research

Redox-activated MRI contrast agents based on lanthanide and transition metal ions.
Abstract The reduction/oxidation (redox) potential of tissue is tightly regulated in order to maintain normal physiological processes, but is disrupted in disease states. Thus, the development of new tools to map tissue redox potential may be clinically important for the diagnosis of diseases that lead to redox imbalances. One promising area of chemical research is the development of redox-activated probes for mapping tissue through magnetic resonance imaging (MRI). In this review, we summarize several strategies for the design of redox-responsive MRI contrast agents. Our emphasis is on both lanthanide(III) and tr...
Source: Journal of Inorganic Biochemistry - January 30, 2014 Category: Biochemistry Authors: Tsitovich PB, Burns PJ, McKay AM, Morrow JR Tags: J Inorg Biochem Source Type: research

Toxic metal proteomics: Reaction of the mammalian zinc proteome with Cd(2+)
Abstract The hypothesis was tested that Cd(2+) undergoes measureable reaction with the Zn-proteome through metal ion exchange chemistry. The Zn-proteome of pig kidney LLC-PK1 cells is relatively inert to reaction with competing ligands, including Zinquin acid, EDTA, and apo-metallothionein. Upon reaction of Cd(2+) with the Zn-proteome, Cd(2+) associates with the proteome and near stoichiometric amounts of Zn(2+) become reactive with these chelating agents. The results strongly support the hypothesis that Cd(2+) displaces Zn(2+) from native proteomic binding sites resulting in the formation of a Cd-proteome. Mobili...
Source: Journal of Inorganic Biochemistry - January 25, 2014 Category: Biochemistry Authors: Namdarghanbari MA, Bertling J, Krezoski S, Petering DH Tags: J Inorg Biochem Source Type: research

F-box and leucine-rich repeat protein 5 (FBXL5): Sensing intracellular iron and oxygen.
Abstract Though essential for many vital biological processes, excess iron results in the formation of damaging reactive oxygen species (ROS). Therefore, iron metabolism must be tightly regulated. F-box and leucine-rich repeat protein 5 (FBXL5), an E3 ubiquitin ligase subunit, regulates cellular and systemic iron homeostasis by facilitating iron regulatory protein 2 (IRP2) degradation. FBXL5 possesses an N-terminal hemerythrin (Hr)-like domain that mediates its own differential stability by switching between two different conformations to communicate cellular iron availability. In addition, the FBXL5-Hr domain als...
Source: Journal of Inorganic Biochemistry - January 25, 2014 Category: Biochemistry Authors: Ruiz JC, Bruick RK Tags: J Inorg Biochem Source Type: research

Hydrogen sulfide activation in hemeproteins: The sulfheme scenario.
López-Garriga J Abstract Traditionally known as a toxic gas, hydrogen sulfide (H2S) is now recognized as an important biological molecule involved in numerous physiological functions. Like nitric oxide (NO) and carbon monoxide (CO), H2S is produced endogenously in tissues and cells and can modulate biological processes by acting on target proteins. For example, interaction of H2S with the oxygenated form of human hemoglobin and myoglobin produces a sulfheme protein complex that has been implicated in H2S degradation. The presence of this sulfheme derivative has also been used as a marker for endogenous H2S...
Source: Journal of Inorganic Biochemistry - January 25, 2014 Category: Biochemistry Authors: Ríos-González BB, Román-Morales EM, Pietri R, López-Garriga J Tags: J Inorg Biochem Source Type: research

Synthesis, spectroscopic and DFT structural characterization of two novel ruthenium(III) oxicam complexes. In vivo evaluation of anti-inflammatory and gastric damaging activities.
Abstract The reactions of ruthenium(III) chloride trihydrate with piroxicam (H2PIR) and tenoxicam (H2TEN), two widely used non-steroidal anti-inflammatory drugs, afforded [Ru(III)Cl2(H2PIR)(HPIR)],·1, and [Ru(III)Cl2(H2TEN)(HTEN)],·2. Both compounds were obtained as pure green solids through purification via flash column chromatography. Characterizations were accomplished through UV-vis and IR spectroscopy, potentiometry and HPLC. Quantum mechanics and density functional computational methods were applied to investigate their respective molecular structures. The experimental and computational results...
Source: Journal of Inorganic Biochemistry - January 25, 2014 Category: Biochemistry Authors: Tamasi G, Bernini C, Corbini G, Owens NF, Messori L, Scaletti F, Massai L, Giudice PL, Cini R Tags: J Inorg Biochem Source Type: research

Nitric oxide photorelease from a trinuclear ruthenium nitrosyl complex and its in vitro cytotoxicity against melanoma cells.
Abstract In vitro cytotoxicity study of the [Ru3O(CH3COO)6(4-pic)2(NO)]PF6 triruthenium nitrosyl cluster (compound 1, 4-pic=4-methylpyridine) against B16F10 melanoma cell line was evaluated in the presence and absence of visible light irradiation. The nitrosyl cluster 1 showed a significant tumoricidal activity when irradiated at λ=532nm, reducing cell viability up to 90% at a concentration of 62.5μM. However, cell death of 60% is also observed in the dark which can be assigned to the NO release mediated by a redox reaction of the cluster in cell medium. This possibility was confirmed by amperometric det...
Source: Journal of Inorganic Biochemistry - January 24, 2014 Category: Biochemistry Authors: Carneiro ZA, Biazzotto JC, Alexiou AD, Nikolaou S Tags: J Inorg Biochem Source Type: research

Self-assembly triggered by self-assembly: Optically active, paramagnetic micelles encapsulated in protein cage nanoparticles.
en JJ Abstract In this contribution, optically active and paramagnetic micelles of the ligand 1,4,7,10-tetraaza-1-(1-carboxymethylundecane)-4,7,10-triacetic acid cyclododecane (DOTAC10) have been incorporated inside capsids of the cowpea chlorotic mottle virus (CCMV) protein through a hierarchical process of self-assembly triggered by self-assembly. The DOTAC10 ligand was used to complex Gd(III), in order to form paramagnetic micelles, as well as to encapsulate an amphiphilic Zn(II) phthalocyanine (ZnPc) dye that optically confirmed the encapsulation of the micelles. The incorporation of ZnPc molecules in the para...
Source: Journal of Inorganic Biochemistry - January 22, 2014 Category: Biochemistry Authors: Millán JG, Brasch M, Anaya-Plaza E, de la Escosura A, Velders AH, Reinhoudt DN, Torres T, Koay MS, Cornelissen JJ Tags: J Inorg Biochem Source Type: research

A glance at the reactivity of osma(II)cycles [Os(C-N)x(bpy)3-x](m+) (x=0-3) Covering a 1.8V Potential Range toward Peroxidase through Monte Carlo Simulations ((-)C-N=o-2-phenylpyridinato, bpy=2,2'-bipyridine).
ov AD Abstract Three cyclometalated and one coordination compounds [Os(C-N)x(bpy)3-x](m) (x/m=0/2+ (4); 1/1+ (3); 2/1+ (2); 3/0 (1); (-)C-N=2-phenylpyridinato, bpy=2,2'-bipyridine) with drastically different reduction potentials have been used for analyzing the second-order rate constants for one-electron, metal-based osmium(II) to osmium(III) oxidation of the complexes by compound I (k2) and compound II (k3) of horseradish peroxidase. Previously unknown k2 and k3 have been determined by digital simulation of cyclic voltammograms measured in phosphate buffer of pH7.6 and 21±1°C. Osmium(II) species deriv...
Source: Journal of Inorganic Biochemistry - January 22, 2014 Category: Biochemistry Authors: Cerón-Camacho R, Le Lagadec R, Kurnikov IV, Ryabov AD Tags: J Inorg Biochem Source Type: research

Regulation of iron transport systems in Enterobacteriaceae in response to oxygen and iron availability.
Abstract Iron is an essential nutrient for most bacteria. Depending on the oxygen available in the surrounding environment, iron is found in two distinct forms: ferrous (Fe(II)) or ferric (Fe(III)). Bacteria utilize different transport systems for the uptake of the two different forms of iron. In oxic growth conditions, iron is found in its insoluble, ferric form, and in anoxic growth conditions iron is found in its soluble, ferrous form. Enterobacteriaceae have adapted to transporting the two forms of iron by utilizing the global, oxygen-sensing regulators, ArcA and Fnr to regulate iron transport genes in respons...
Source: Journal of Inorganic Biochemistry - January 22, 2014 Category: Biochemistry Authors: Carpenter C, Payne SM Tags: J Inorg Biochem Source Type: research

Nitric oxide as a non-innocent ligand in (bio-)inorganic complexes: Spin and electron transfer in Fe(II)NO bond.
Abstract The nature of electron density transfer upon bond formation between NO ligand and Fe(II) center is analyzed on the basis of DFT calculation for two {Fe-NO}(7) complexes with entirely diverse geometric and electronic structures: Fe(II)P(NH3)NO (with bent Fe-N-O unit) and [Fe(II)(H2O)5(NO)](2+) (with linear Fe-N-O structure). Proper identification of an electronic status of the fragments, "prepared" to make a bond, was found necessary to get meaningful resolution of charge and spin transfer processes from a spin-resolved analysis of natural orbitals for chemical valence. The Fe(II)P(NH3)NO adduct ...
Source: Journal of Inorganic Biochemistry - January 22, 2014 Category: Biochemistry Authors: Broclawik E, Stępniewski A, Radoń M Tags: J Inorg Biochem Source Type: research

How plants sense ethylene gas - The ethylene receptors.
We present a model where a copper cofactor is required and the binding of ethylene causes the receptor to pass through a transition state to become non-signaling leading to lower CTR1 activity. PMID: 24485009 [PubMed - as supplied by publisher] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - January 21, 2014 Category: Biochemistry Authors: Lacey RF, Binder BM Tags: J Inorg Biochem Source Type: research

Modulation of nuclear receptor function by cellular redox poise.
Abstract Nuclear receptors (NRs) are ligand-responsive transcription factors involved in diverse cellular processes ranging from metabolism to circadian rhythms. This review focuses on NRs that contain redox-active thiol groups, a common feature within the superfamily. We will begin by describing NRs, how they regulate various cellular processes and how binding ligands, corepressors and/or coactivators modulate their activity. We will then describe the general area of redox regulation, especially as it pertains to thiol-disulfide interconversion and the cellular systems that respond to and govern this redox equili...
Source: Journal of Inorganic Biochemistry - January 21, 2014 Category: Biochemistry Authors: Carter EL, Ragsdale SW Tags: J Inorg Biochem Source Type: research

Multiple spectroscopic and magnetic techniques show that chloroquine induces formation of the μ-oxo dimer of ferriprotoporphyrin IX.
Multiple spectroscopic and magnetic techniques show that chloroquine induces formation of the μ-oxo dimer of ferriprotoporphyrin IX. J Inorg Biochem. 2014 Jan 16;133C:40-49 Authors: Kuter D, Benjamin SJ, Egan TJ Abstract Interaction of the antimalarial chloroquine (CQ) with ferriprotoporphyrin IX, Fe(III)PPIX, was investigated in aqueous solution (pH7.4) and as a precipitate from aqueous medium at pH5.0. In solution, spectrophotometric titrations indicated strong association (logKobs 13.3±0.2) and a Job plot gave a stoichiometry of 1:2 CQ:Fe(III)PPIX. UV-visible absorbance and magnetic circular d...
Source: Journal of Inorganic Biochemistry - January 16, 2014 Category: Biochemistry Authors: Kuter D, Benjamin SJ, Egan TJ Tags: J Inorg Biochem Source Type: research

The solution structure of the copper clioquinol complex.
Abstract Clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) recently has shown promising results in the treatment of Alzheimer's disease and in cancer therapy, both of which also are thought to be due to clioquinol's ability as a lipophilic copper chelator. Previously, clioquinol was used as an anti-fungal and anti-protozoal drug that was responsible for an epidemic of subacute myelo-optic neuropathy (SMON) in Japan during the 1960s, probably a myeloneuropathy arising from a clioquinol-induced copper deficiency. Previous X-ray absorption spectroscopy of solutions of copper chelates of clioquinol suggested unusual coo...
Source: Journal of Inorganic Biochemistry - January 16, 2014 Category: Biochemistry Authors: Pushie MJ, Nienaber KH, Summers KL, Cotelesage JJ, Ponomarenko O, Nichol HK, Pickering IJ, George GN Tags: J Inorg Biochem Source Type: research

A facile and versatile methodology for cysteine specific labeling of proteins with octahedral polypyridyl d(6) metal complexes.
Abstract We have synthesized and characterized four octahedral polypyridyl d(6) metal complexes bearing the 5,6-epoxy-5,6-dihydro-[1,10]phenanthroline ligand (L1) as cysteine specific labeling reagents. The proposed synthetic pathways allow the preparation of the metal complexes containing Re(I), Ru(II), Os(II) and Ir(III) while preserving the epoxide functionality. The complexes were characterized by (1)H and (13)C NMR, mass spectrometry, UV-visible and luminescence spectroscopies as well as cyclic voltammetry. As proof of concept, a set of non-native single cysteine P450 BM3 heme domain mutants previously develo...
Source: Journal of Inorganic Biochemistry - January 10, 2014 Category: Biochemistry Authors: Dwaraknath S, Tran NH, Dao T, Colbert A, Mullen S, Nguyen A, Cortez A, Cheruzel L Tags: J Inorg Biochem Source Type: research

Inhibition of the 26S proteasome as a possible mechanism for toxicity of heavy metal species.
Abstract In this paper we report on the synthesis of five metal complexes coordinated to the [NN'O] ligand HL(iodo) (2,4-diiodo-6-((pyridine-2-ylmethylamino)methyl)phenol), namely [Al(III)(L(iodo))2]ClO4 (1), [Cd(II)(L(iodo))Cl]·H2O (2), [Hg(II)(L(iodo))2]·4DMSO (3), [Pb(II)(L(iodo))NO3] (4), and [Sn(IV)(L(iodo))Cl3] (5). Species 1-5 are thoroughly characterized by spectroscopic and spectrometric methods, as well as by elemental analysis. X-ray crystallography results for complex 3 indicate the presence of Hg(II) ion hexacoordinated to two facially oriented [NN'O] ligands, whereas for complex 5 an Sn...
Source: Journal of Inorganic Biochemistry - January 8, 2014 Category: Biochemistry Authors: Tomco D, Schmitt S, Heeg MJ, Dou QP, Verani CN Tags: J Inorg Biochem Source Type: research

Hydrothermal synthesis of copper based nanoparticles: Antimicrobial screening and interaction with DNA.
Abstract Copper based nanoparticles (Cu-based NPs) of different compositions and sizes have been hydrothermally synthesized by varying the reaction time in the presence of the biocompatible surfactants polyoxyethylene (20) sorbitan laurate (Tween 20) and polyethylene glycol 8000 (PEG 8000). Effective control of the above synthetic parameters gave rise to Cu, Cu2O and Cu/Cu2O NPs of 10-44nm. The antibacterial activity of the NPs was screened against Gram-positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus) and Gram-negative (Xanthomonas campestris, Escherichia coli) bacteria. The Cu-based NPs induce...
Source: Journal of Inorganic Biochemistry - January 3, 2014 Category: Biochemistry Authors: Giannousi K, Lafazanis K, Arvanitidis J, Pantazaki A, Dendrinou-Samara C Tags: J Inorg Biochem Source Type: research

Synthesis and ESI mass spectrometric analysis of the association of mercury(II) with multi-cysteinyl peptides.
Abstract In order to gain more insight into the associations of mercury(II) with cysteinyl peptides, we investigated the effect of increasing cysteinyl residues on complex type formations. Three series of di-, tri-, and tetra-cysteinyl peptides, D[CGD]nCG (CP 2A, CP 3A, and CP 4A), E[CEG]nCG (CP 2B, CP 3B, and CP 4B) and E[CDG]nCG (CP 2C, CP 3C, and CP 4C), where n=1, 2, or 3, were prepared by microwave-assisted solid phase peptide synthesis. Complexes formed in different relative ratios of mercury(II) to cysteinyl peptides were characterized by electrospray orbitrap mass spectrometry utilizing complex specific me...
Source: Journal of Inorganic Biochemistry - December 27, 2013 Category: Biochemistry Authors: Ngu-Schwemlein M, Lin X, Rudd B, Bronson M Tags: J Inorg Biochem Source Type: research

Further insight into the inhibitory action of a LIM/double zinc-finger motif of an agmatinase-like protein.
rvajal N, Uribe E Abstract Agmatine is a precursor for polyamine biosynthesis also associated to neurotransmitter, anticonvulsant, antineurotoxic and antidepressant actions in the brain. It results from decarboxylation of l-arginine by arginine decarboxylase and it is hydrolyzed to urea and putrescine by agmatinase. Recently, we have described a new protein which also hydrolyzes agmatine although its sequence greatly differs from all known agmatinases. This agmatinase-like protein (ALP) contains a LIM-like double Zn-finger domain close to its carboxyl terminus, whose removal results in a truncated variant with a 1...
Source: Journal of Inorganic Biochemistry - December 25, 2013 Category: Biochemistry Authors: Cofre J, Montes P, Vallejos A, Benítez J, García D, Martínez-Oyanedel J, Carvajal N, Uribe E Tags: J Inorg Biochem Source Type: research

Synthesis, characterization, and cytotoxicity studies of Cu(II), Zn(II), and Fe(III) complexes of N-derivatized 3-hydroxy-4-pyridiones.
BO, Orvig C Abstract The deleterious role of metal ions in Alzheimer's disease has inspired the study of various metal chelators. We previously showed the synthesis and in vitro activity of several bidentate hydroxypyridinone compounds, including 3-hydroxy-2-methyl-1-phenyl-4(1H)-pyridinone (1), 1-(4-aminophenyl)-3-hydroxy-2-methyl-4(1H)-pyridinone (2), and 1-(2-benzothiazolyl)-3-hydroxy-2-methyl-4(1H)-pyridinone (3). While the focus has been on the Cu(II) ion, the other biorelevant metals, Zn(II) and Fe(III) have been largely neglected. Herein, we report the synthesis of Zn(II) and Fe(III) complexes of ligands 1,...
Source: Journal of Inorganic Biochemistry - December 22, 2013 Category: Biochemistry Authors: Telpoukhovskaia MA, Rodríguez-Rodríguez C, Scott LE, Page BD, Patrick BO, Orvig C Tags: J Inorg Biochem Source Type: research

Improved separation of the curcuminoids, syntheses of their rare earth complexes, and studies of potential antiosteoporotic activity.
Abstract The first reported homogenous rare earth curcumin (HCurc; ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione)) complexes with the formula ML3, where M(3+) is Eu(III), Gd(III) or Lu(III), were synthesized and characterized by mass spectrometry, infrared spectroscopy and, in the case of the lutetium complex, (1)H NMR spectroscopy. Most importantly an improved separation of the three curcuminoids, HCurc, HDMC ((1E,6E)-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-1,6-diene-3,5-dione) and HBDMC ((1E,6E)-1,7-bis(4-hydroxyphenyl)hepta-1,6-diene-3,5-dione) was realized using a combinat...
Source: Journal of Inorganic Biochemistry - December 21, 2013 Category: Biochemistry Authors: Mawani Y, Orvig C Tags: J Inorg Biochem Source Type: research

Structural characterization of Cd(2+) complexes in solution with DMSA and DMPS.
Abstract Meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonic acid (DMPS) are chelating agents which have been used clinically to treat patients suffering from Pb(2+) or Hg(2+) exposure. Cd(2+) is a related environmental pollutant that is of increasing public health concern due to a demonstrated dose-response between urinary Cd level and an increased risk of diabetes. However, therapeutically effective chelating agents which enhance the excretion of Cd(2+) from humans have yet to be identified. Here we present a structural characterization of complexes of DMSA and DMPS with Cd(2+) at physio...
Source: Journal of Inorganic Biochemistry - December 4, 2013 Category: Biochemistry Authors: Zeini Jahromi E, Gailer J, Pickering IJ, George GN Tags: J Inorg Biochem Source Type: research

Oxidative stress sensing by the iron-sulfur cluster in the transcription factor, SoxR.
Abstract All bacteria are continuously exposed to environmental and/or endogenously active oxygen and nitrogen compounds and radicals. To reduce the deleterious effects of these reactive species, most bacteria have evolved specific sensor proteins that regulate the expression of enzymes that detoxify these species and repair proteins. Some bacterial transcriptional regulators containing an iron-sulfur cluster are involved in coordinating these physiological responses. Mechanistic and structural information can show how these regulators function, in particular, how chemical interactions at the cluster drive subsequ...
Source: Journal of Inorganic Biochemistry - November 28, 2013 Category: Biochemistry Authors: Kobayashi K, Fujikawa M, Kozawa T Tags: J Inorg Biochem Source Type: research

A study on the properties and reactivity of naphthoquinone-cobalt(III) prototypes for bioreductive prodrugs.
Abstract Our group has recently initiated a study on the development of new prototypes for bioreductive prodrugs, based on Co(III) complexes with the ligand 2,2'-bis(3-hydroxy-1,4-naphthoquinone), H2bhnq. The focus of this work is to investigate the dissociation of bhnq(-2) from the complex upon reduction, and the effects of pH, redox potential, oxygen concentration and nature of the auxiliary ligands on this reaction. The bhnq(2-) ligand is a "non-cytotoxic" agent that was chosen as a probe for the reactivity studies due to its suitable chromophoric properties, at the same time that it resembles more cy...
Source: Journal of Inorganic Biochemistry - November 27, 2013 Category: Biochemistry Authors: Bustamante FL, Miranda FS, Castro FA, Resende JA, Pereira MD, Lanznaster M Tags: J Inorg Biochem Source Type: research

Insights into redox sensing metalloproteins in Mycobacterium tuberculosis.
Abstract Mycobacterium tuberculosis, the pathogen that causes tuberculosis, has evolved sophisticated mechanisms for evading assault by the human host. This review focuses on M. tuberculosis regulatory metalloproteins that are sensitive to exogenous stresses attributed to changes in the levels of gaseous molecules (i.e., molecular oxygen, carbon monoxide and nitric oxide) to elicit an intracellular response. In particular, we highlight recent developments on the subfamily of Whi proteins, redox sensing WhiB-like proteins that contain iron-sulfur clusters, sigma factors and their cognate anti-sigma factors of which...
Source: Journal of Inorganic Biochemistry - November 15, 2013 Category: Biochemistry Authors: Chim N, Johnson PM, Goulding CW Tags: J Inorg Biochem Source Type: research

Overexpression, purification, and enthalpy of unfolding of ferricytochrome c552 from a psychrophilic microorganism.
Abstract The psychrophilic, hydrocarbonoclastic microorganism Colwellia psychrerythraea is important in global nutrient cycling and bioremediation. In order to investigate how this organism can live so efficiently at low temperatures (~4°C), thermal denaturation studies of a small electron transfer protein from Colwellia were performed. Colwellia cytochrome c552 was overexpressed in Escherichia coli, isolated, purified, and characterized by UV-visible absorption spectroscopy. The melting temperature (Tm) and the van't Hoff enthalpy (ΔHvH) were determined. These values suggest an unexpectedly high stabili...
Source: Journal of Inorganic Biochemistry - November 12, 2013 Category: Biochemistry Authors: Oswald VF, Chen W, Harvilla PB, Magyar JS Tags: J Inorg Biochem Source Type: research

Molecular mechanisms of heme based sensors from sediment organisms capable of extracellular electron transfer.
Abstract Bioelectrochemical systems (BES) rely on the metabolism of sediment bacteria capable of forming electrogenic biofilms to generate electrical work. The environment across the thickness of the biofilm is variable and in order for the cells to maintain their viability they require molecular sensors that allow them to adapt their metabolism to their respective environment. The DcrA sensor from Desulfovibrio vulgaris and the GSU 0582 and 0935 sensor domains from Geobacter sulfurreducens appear to function as redox sensors. The SO2144 sensor domain from Shewanella oneidensis MR-1 and the cytochrome c″ fro...
Source: Journal of Inorganic Biochemistry - November 8, 2013 Category: Biochemistry Authors: Fonseca BM, Paquete CM, Louro RO Tags: J Inorg Biochem Source Type: research

Heteronuclear gold(I)-silver(I) sulfanylcarboxylates: Synthesis, structure and cytotoxic activity against cancer cell lines.
z-López EM Abstract Heteronuclear complexes of the type [AgAu(PPh3)2(xspa)] [H2xspa=3-(aryl)-2-sulfanylpropenoic acids; (x=3-phenyl-; 3-(2-chlorophenyl)-; 3-(o-methoxyphenyl)-; 3-(p-methoxyphenyl)-; 3-(p-hydroxyphenyl)-; 3-(2-furyl)-; 3-(2-thienyl)-; spa=2-sulfanylpropenoate)] were prepared by reacting the appropriate [Au(PPh3)(Hxspa)] precursor with Ag(PPh3)NO3. The compounds were characterized by spectroscopic methods, (IR; (1)H, (13)C and (31)P NMR) and mass spectrometry and the structures of the phenyl and p-methoxyphenyl derivatives were determined by X-ray diffraction. The in vitro antitumor activity ...
Source: Journal of Inorganic Biochemistry - November 1, 2013 Category: Biochemistry Authors: Barreiro E, Casas JS, Couce MD, Sánchez A, Sordo J, Vázquez-López EM Tags: J Inorg Biochem Source Type: research

Guest editorial.
PMID: 24125591 [PubMed - as supplied by publisher] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - October 17, 2013 Category: Biochemistry Authors: Exley C Tags: J Inorg Biochem Source Type: research

Synthesis and in vitro antitumor activity of water soluble sulfonate- and ester-functionalized silver(I) N-heterocyclic carbene complexes.
Abstract The novel N-heterocyclic carbene ligand precursor NaHIm(PrSO3) (sodium 3,3'-(1H-imidazole-3-ium-1,3-diyl)dipropane-1-sulfonate) and the related silver carbene complex [Na4(Im(PrSO3))2]AgCl have been synthesized and characterized. Recrystallization of the analogous [Im(AcEt)]AgCl complex allowed the development of X-ray analysis which led to achieve relevant structural information concerning this silver(I) derivative. Both sulfonate- and ester-functionalized silver(I) N-heterocyclic carbenes (NHCs) were evaluated for their antiproliferative activities in a wide panel of human cancer cells. Complex [Na4(Im(...
Source: Journal of Inorganic Biochemistry - September 24, 2013 Category: Biochemistry Authors: Gandin V, Pellei M, Marinelli M, Marzano C, Dolmella A, Giorgetti M, Santini C Tags: J Inorg Biochem Source Type: research