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

Dioxygen and superoxide stability of metallopeptide based mimics of nickel containing superoxide dismutase: The influence of amine/amidate vs. bis-amidate ligation.
Abstract Nickel containing superoxide dismutase (NiSOD) is a metalloenzyme that catalyzes the disproportionation of O2(-). In its reduced state, the Ni(II) ion is coordinated by two cis-cysteinates, an amine nitrogen and an amidate nitrogen atom. It thus bears a resemblance to the distal bis-cysteinate bis-amidate ligated nickel center of acetyl coenzyme A synthase. Using metallopeptide based NiSOD mimics derived from the first 12 residues of the NiSOD sequence we demonstrate that altering the primary coordination sphere from a bis-thiolate amine/amidate motif to a bis-thiolate bis-amidate motif changes the O2 and...
Source: Journal of Inorganic Biochemistry - September 21, 2013 Category: Biochemistry Authors: Shearer J Tags: J Inorg Biochem Source Type: research

Exploring the effect of the ligand design on the interactions between [Ru(η(5)-C5H5)(PPh3)(N,O)][CF3SO3] complexes and human serum albumin.
Exploring the effect of the ligand design on the interactions between [Ru(η(5)-C5H5)(PPh3)(N,O)][CF3SO3] complexes and human serum albumin. J Inorg Biochem. 2013 Sep 18;129C:94-101 Authors: Morais TS, Santos FC, Corte-Real L, Garcia MH Abstract Ruthenium complexes hold a great potential in chemotherapy as an alternative to the classical platinum based drugs. The organometallic compounds studied in the present work were previously found to exhibit important anticancer activities. Here we have investigated the binding of three ruthenium compounds, namely [Ru(η(5)-C5H5)(PPh3)(bopy)][CF3SO3] 1, [Ru(&et...
Source: Journal of Inorganic Biochemistry - September 18, 2013 Category: Biochemistry Authors: Morais TS, Santos FC, Corte-Real L, Garcia MH Tags: J Inorg Biochem Source Type: research

Metal-polybenzimidazole complexes as a nonviral gene carrier: Effects of the DNA affinity on gene delivery.
Abstract The metal complex-based carriers are emerging likely as a new type of gene-delivery systems prone to systematic structural alteration and chemical tailoring. In our work, the DNA affinity of metal complexes with polybenzimidazoles was found to be one of the determinants that can regulate expression of the transgenes. Here, the correlations between the DNA affinity and transfection efficacy were explored by characterizing gene-delivering properties of a series of Co(2+)- and Ca(2+)-polybenzimidazole complexes. The binding equilibrium constants (Kobs) of the divalent metal complexes to DNA, which is conside...
Source: Journal of Inorganic Biochemistry - September 18, 2013 Category: Biochemistry Authors: Huang X, Dong X, Li X, Meng X, Zhang D, Liu C Tags: J Inorg Biochem Source Type: research

Imino-phosphine palladium(II) and platinum(II) complexes: Synthesis, molecular structures and evaluation as antitumor agents.
Abstract The imino-phosphine ligands L1 and L2 were prepared via condensation reaction of 2-(diphenylphosphino)benzaldehyde with substituted anilines and obtained in very good yields. An equimolar reaction of L1 and L2 with either PdCl2(cod) or PtCl2(cod) gave new palladium(II) and platinum(II) complexes 1-4. The compounds were characterized by elemental analysis, IR, (1)H and (31)P NMR spectroscopy. The molecular structures of 2, 3 and 4 were confirmed by X-ray crystallography. All the three molecular structures crystallized in monoclinic C2/c space system. The coordination geometry around the palladium and plati...
Source: Journal of Inorganic Biochemistry - September 18, 2013 Category: Biochemistry Authors: Motswainyana WM, Onani MO, Madiehe AM, Saibu M, Thovhogi N, Lalancette RA Tags: J Inorg Biochem Source Type: research

DFT study of cisplatin@carbon nanohorns complexes.
Abstract This paper reports a quantum chemical investigation of the inclusion complex formation between a carbon nanohorn structure and cisplatin molecule, using the density functional theory (DFT) with the B3LYP functional and 6-31G(d,p)/LanL2DZ standard basis sets. The inclusion of the drug in host molecules such as carbon nanohorns (CNHs), aims to reduce the toxicity and enhance the effectiveness of cisplatin. In this work we carried out a search for minimum energy structures on the potential energy surface (PES) for CNH-cisplatin interaction, and then calculated the stabilization energy, charge distribution an...
Source: Journal of Inorganic Biochemistry - September 18, 2013 Category: Biochemistry Authors: De Souza LA, Nogueira CA, Lopes JF, Dos Santos HF, De Almeida WB Tags: J Inorg Biochem Source Type: research

Dissecting regulation mechanism of the FMN to heme interdomain electron transfer in nitric oxide synthases.
Abstract Nitric oxide synthase (NOS), a flavo-hemoprotein, is responsible for biosynthesis of nitric oxide (NO) in mammals. Three NOS isoforms, iNOS, eNOS and nNOS (inducible, endothelial, and neuronal NOS), achieve their biological functions by tight control of interdomain electron transfer (IET) process through interdomain interactions. In particular, the FMN-heme IET is essential in coupling electron transfer in the reductase domain with NO synthesis in the heme domain by delivery of electrons required for O2 activation at the catalytic heme site. Emerging evidence indicates that calmodulin (CaM) activates NO s...
Source: Journal of Inorganic Biochemistry - September 13, 2013 Category: Biochemistry Authors: Feng C, Chen L, Li W, Elmore BO, Fan W, Sun X Tags: J Inorg Biochem Source Type: research

Binding ability of glutathione towards alkyltin(IV) compounds in aqueous solution.
oli A Abstract The interactions between glutathione (H3GSH) and (CH3)2Sn(2+), (CH3)3Sn(+), (C2H5)3Sn(+) and (C3H7)3Sn(+) cations were studied by potentiometry, UV spectrophotometry, (1)H NMR spectroscopy and electrospray mass spectrometry (ESI MS). Potentiometric measurements evidenced speciation models very similar for all the alkyltin(IV) cation-GSH(3-) systems, with the formation of M(GSH)(z-3), M(GSH)H(z-2) and M(GSH)H2(z-1) species [M(z+)=(CH3)2Sn(2+), (CH3)3Sn(+), (C2H5)3Sn(+), or (C3H7)3Sn(+)] and, for dimethyltin(IV) cation, also the mixed hydrolytic M(GSH)(OH)(2-) one. The equilibrium behavior in NaCl aqu...
Source: Journal of Inorganic Biochemistry - September 13, 2013 Category: Biochemistry Authors: Cardiano P, Falcone G, Foti C, Giuffrè O, Napoli A Tags: J Inorg Biochem Source Type: research

Antiproliferative activity of Pt(IV)-bis(carboxylato) conjugates on malignant pleural mesothelioma cells.
Abstract The bifunctional Pt(IV) conjugate cis,cis,trans-diamminedichloridobis(valproato)platinum(IV), based on the cisplatin square-plane with two axial valproato (2-propylpentanoate, VPA) ligands, has been re-synthesized with a modified procedure and its biological activity was compared with that of its isomer cis,cis,trans-diamminedichloridobis(n-octanoato)platinum(IV). Both complexes showed a striking cytotoxic effect (in the micro or sub-micromolar range) on various human carcinoma cell lines (namely ovarian, colon, breast and lung cancer), and, in particular, on cells derived from malignant pleural mesotheli...
Source: Journal of Inorganic Biochemistry - September 13, 2013 Category: Biochemistry Authors: Alessio M, Zanellato I, Bonarrigo I, Gabano E, Ravera M, Osella D Tags: J Inorg Biochem Source Type: research

Cu(II) complex formation by ACES buffer.
Bal W Abstract ACES (N-(2-Acetamido)-2-aminoethanesulfonic acid), a popular Good's buffer, binds Cu(II) ions with a moderate affinity. Although this interaction was the subject of previous studies, no consensus in the literature was found. We used potentiometry to establish binding constants, and controlled the potentiometric model selection and binding constant calculations by UV-vis spectroscopy. As a result, we obtained a consistent set of complex stoichiometries and binding constants in this system, which contains Cu(2+), CuL(+), CuL2, CuH-1L2(-1) and CuH(-)2L2(-2) complexes. The negative indexes at H atoms in...
Source: Journal of Inorganic Biochemistry - September 6, 2013 Category: Biochemistry Authors: Zawisza I, Rózga M, Poznański J, Bal W Tags: J Inorg Biochem Source Type: research

Quantum mechanical investigation of aqueous desferrioxamine B metal complexes: Trends in structure, binding, and infrared spectroscopy.
Abstract A systematic density functional theory study supported by extended X-ray absorption fine structure (EXAFS) and infrared spectroscopic data was conducted to elucidate how structure and vibrational spectra of aqueous desferrioxamine B (DFOB) metal complexes vary with the metal ion identity. Structural parameters derived from EXAFS analyses and trends in metal binding constants are well reproduced and validated by the applied computational model. Vibrational mode analysis guides determination and recognition of crucial structure- and metal-sensitive infrared marker bands. The key marker bands, CO and CN stre...
Source: Journal of Inorganic Biochemistry - August 31, 2013 Category: Biochemistry Authors: Kruft BI, Harrington JM, Duckworth OW, Jarzęcki AA Tags: J Inorg Biochem Source Type: research

Anti-plasmodial activity of aroylhydrazone and thiosemicarbazone iron chelators: Effect on erythrocyte membrane integrity, parasite development and the intracellular labile iron pool.
This study has implications for malaria chemotherapy that specifically disrupts parasite iron utilization. PMID: 24028863 [PubMed - as supplied by publisher] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - August 26, 2013 Category: Biochemistry Authors: Walcourt A, Kurantsin-Mills J, Kwagyan J, Adenuga BB, Kalinowski DS, Lovejoy DB, Lane DJ, Richardson DR Tags: J Inorg Biochem Source Type: research

Structural effects on the hesperidin properties obtained by chelation to magnesium complexes.
os RM Abstract The magnesium complex [Mg(hesp)2(phen)] (1), where hesp=hesperidin and phen=1,10'-phenanthroline, was synthesized and characterized by Elemental Analysis (C,H,N), atomic absorption and spectroscopic (FTIR, UV-visible, (1)H NMR) techniques. The congested structure facilitates the tilting and contact of the two hesperidin ligands by hydrogen bonding interactions having a stabilizer effect on the hesperidin. The hydrogen bonds are strongly affected by the solvent used which can lead to changes in the physical-chemical, luminescence and biologic properties of complex 1. Complex 1 is more hydrosoluble (S...
Source: Journal of Inorganic Biochemistry - August 23, 2013 Category: Biochemistry Authors: Oliveira RM, de Souza Daniel JF, de Aguiar I, das Graças Fernandes Silva MF, Batista Fernandes J, Carlos RM Tags: J Inorg Biochem Source Type: research

Reduction of the internal disulfide bond between Cys 38 and 83 switches the ligand migration pathway in cytoglobin.
Abstract Despite the similar tertiary structure between cytoglobin (Cygb) and myoglobin, several structural features indicate a distinct mechanism of Cygb interactions with exogenous ligands. Here we present a spectroscopic investigation of the dynamics and thermodynamics of structural changes associated with the exogenous ligand migration between the solvent and the heme active site in Cygb with reduced and oxidized Cys 38 and Cys 83 side-chains (Cygb(ox) and Cygb(red), respectively). Photo-acoustic and transient absorption data show that disulfide bond formation alters the ligand migration pathway(s) as evident ...
Source: Journal of Inorganic Biochemistry - August 16, 2013 Category: Biochemistry Authors: Astudillo L, Bernad S, Derrien V, Sebban P, Miksovska J Tags: J Inorg Biochem Source Type: research

Chemical and cellular investigations of trans-ammine-pyridine-dichlorido-platinum(II), the likely metabolite of the antitumor active cis-diammine-pyridine-chorido-platinum(II).
Abstract It has been proposed that the well-studied monofunctional platinum complex cis-[PtCl(NH3)2(py)](+) (cDPCP) forms DNA adducts similar to those of the trans platinum complex trans-[PtCl2(NH3)(py)] (ampyplatin, py=pyridine). Thus this latter could be the active form of cDPCP. Detailed studies on the mechanism of ampyplatin action were performed in this work. Results indicate that ampyplatin has significantly higher antiproliferative activity than cDPCP and is comparable to cisplatin. Cellular uptake experiments indicate that ampyplatin can be efficiently accumulated in A549 cancer cells. Binding of ampyplati...
Source: Journal of Inorganic Biochemistry - August 14, 2013 Category: Biochemistry Authors: Xu D, Min Y, Cheng Q, Shi H, Wei K, Arnesano F, Natile G, Liu Y Tags: J Inorg Biochem Source Type: research

Preface.
te;s-Gutiérrez J PMID: 23993869 [PubMed - as supplied by publisher] (Source: Journal of Inorganic Biochemistry)
Source: Journal of Inorganic Biochemistry - August 14, 2013 Category: Biochemistry Authors: Domínguez-Martín A, Niclós-Gutiérrez J Tags: J Inorg Biochem Source Type: research