Effect of Dinitrosyl Iron Complex on Albumin Conformation
AbstractBinding of dinitrosyl iron complex (DNIC) to albumin was studied using time-resolved fluorescence (TRF) and electron spin resonance (ESR) spectroscopy. It was found that the fluorescence lifetime of bovine serum albumin (BSA) and human serum albumin (HSA) decreases with binding and depends on DNIC concentration. The observed biexponential pattern of the BSA tryptophan (Trp) fluorescence decay is explained by the presence of two tryptophan residues in the protein molecule. We believe that DNIC forms stable complexes with the cysteine (Cys34) residue in the domain I of albumin. It was shown that the lifetime of album...
Source: Biochemistry (Moscow) - April 6, 2021 Category: Biochemistry Source Type: research

Impact of High-Sucrose Diet on the mRNA Levels for Elongases and Desaturases and Estimated Protein Activity in Rat Adipose Tissue
This study supports the notion that the regulation of mRNA levels and activity of both elongases and desaturases play an important role in managing the AT lipid composition in response to changes in the dietary status. (Source: Biochemistry (Moscow))
Source: Biochemistry (Moscow) - April 2, 2021 Category: Biochemistry Source Type: research

Chemical Chaperone PBA Attenuates ER Stress and Upregulates SOCS3 Expression as a Regulator of Leptin Signaling
This study involved twenty-four lean and twenty-four leptin-deficient (ob/ob) mice divided into PBA- and vehicle-treated groups. Pancreatic islets were isolated, incubated with leptin for 48 h, and assayed for the expression of CHOP and XBP1s (UPR signaling indicators) and SOCS3 (regulator of leptin signaling) by RT-qPCR. The expression levels of XBP1s and CHOP were markedly increased in the ob/ob controls compared to other groups with and without leptin treatment. No significant differences in the XBP1s and CHOP expression levels were found between the PBA-treated ob/ob and lean mice. SOCS3 expression was significantly up...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

D-Rhamnan and Pyruvate-Containing Teichuronic Acid from the Cell Wall of Rathayibacter sp. VKM Ac-2759
AbstractRathayibacter sp. VKM Ac-2759 (familyMicrobacteriaceae, class Actinobacteria) contains two glycopolymers in the cell wall. The main chain of rhamnan,glycopolymer 1, is built from the repeating tetrasaccharide units carrying terminal arabinofuranose residues at the non-reducing end, →3)-α-[α-D-Araf-(1 →2)]-D-Rhap-(1 →2)-α-D-Rhap-(1 →3)-α-D-Rhap-(1 →2)-α-D-Rhap-(1 →. Similar to other describedRathayibacter species, rhamnose in the neutral glycopolymer of the VKM Ac-2759 strain is present in the D-configuration. Acetalated with pyruvic acid teichuronic acid,g...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Heterologous Expression of Thermogutta terrifontis Endo-Xanthanase in Penicillium verruculosum , Isolation and Primary Characterization of the Enzyme
AbstractHeterologous endo-xanthanase (EX) from the thermophilic planktomyceteThermogutta terrifontis strain was obtained usingPenicillium verruculosum 537 ( ΔniaD) expression system with the cellobiohydrolase 1 gene promoter. Homogeneous EX with a molecular weight of 23.7 kDa (pI 6.5) was isolated using liquid chromatography methods. This xanthan degrading enzyme also possesses the enzymatic activity towards CM-cellulose, β-glucan, curdlan, lichenan, laminarin, galactomannan, xyloglucan but not towardsp-nitrophenyl derivatives of β-D-glucose, mannose and cellobiose. The temperature and pH optima of EX were ...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Normalization of Calcium Balance in Striatal Neurons in Huntington ’s Disease: Sigma 1 Receptor as a Potential Target for Therapy
AbstractHuntington ’s disease (HD) is a neurodegenerative, dominantly inherited genetic disease caused by expansion of the polyglutamine tract in the huntingtin gene. At the cellular level, HD is characterized by the accumulation of mutant huntingtin protein in brain cells, resulting in the development of the HD phe notype, which includes mental disorders, decreased cognitive abilities, and progressive motor impairments in the form of chorea. Despite numerous studies, no unambigous connection between the accumulation of mutant protein and selective death of striatal neurons has yet been established. Recent stud ies h...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Effect of Detergents and Osmolytes on Thermal Stability of Native and Mutant Rhodobacter sphaeroides Reaction Centers
AbstractPhotosynthetic reaction center (RC) of the purple bacteriumRhodobacter sphaeroides is one of the most well-studied transmembrane pigment-protein complexes. It is a relatively stable protein with established conditions for its isolation from membranes, purification, and storage. However, it has been shown that some amino acid substitutions can affect stability of the RC, which results in a decrease of the RCs yield during its isolation and purification, disturbs spectral properties of the RCs during storage, and can lead to sample heterogeneity. To optimize conditions for studying mutant RCs, the effect of various d...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Antioxidant Properties of Galanin and Its N-Terminal Fragments in in vitro and in vivo Oxidative Stress Modeling
AbstractAntioxidant properties of rat galanin GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2 (Gal), N-terminal fragment of galanin (2-15 aa) WTLNSAGYLLGPHA (G1), and its modified analogue WTLNSAGYLLGP βAH (G2) were studiedin vivo in the rat model of regional myocardial ischemia and reperfusion andin vitro in the process of Cu2+-induced free radical oxidation of human blood plasma low-density lipoproteins. Intravenous administration of G1, G2, and Gal to rats after ischemia induction reduced the infarction size and activities of the necrosis markers, creatine kinase-MB and lactate dehydrogenase, in blood plasma at the end of reperf...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Microbial Arsenal of Antiviral Defenses. Part II
AbstractBacteriophages or phages are viruses that infect bacterial cells (for the scope of this review we will also consider viruses that infect Archaea). The constant threat of phage infection is a major force that shapes evolution of microbial genomes. To withstand infection, bacteria had evolved numerous strategies to avoid recognition by phages or to directly interfere with phage propagation inside the cell. Classical molecular biology and genetic engineering had been deeply intertwined with the study of phages and host defenses. Nowadays, owing to the rise of phage therapy, broad application of CRISPR-Cas technologies...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

A Crosstalk between the Biorhythms and Gatekeepers of Longevity: Dual Role of Glycogen Synthase Kinase-3
AbstractThis review discusses genetic and molecular pathways that link circadian timing with metabolism, resulting in the emergence of positive and negative regulatory feedback loops. The Nrf2 pathway is believed to be a component of the anti-aging program responsible for the healthspan and longevity. Nrf2 enables stress adaptation by activating cell antioxidant defense and other metabolic processes via control of expression of over 200 target genes in response to various types of stress. The GSK3 system represents a “regulating valve” that controls fine oscillations in the Nrf2 level, unlike Keap1, which preve...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Epigenetic Modification of MicroRNA-219-1 and Its Association with Glioblastoma Multiforme
AbstractMicroRNA-219-1 (miR-219-1) acts as a tumor suppressor in a variety of cancers but, the regulatory epigenetic mechanism involved in its gene expression level has not been studied. Using real-time polymerase chain reaction (real-time PCR) and bisulfite genomic sequencing technology, promoter methylation level of miR-219-1 and gene expression levels of miR-219-5p and miR-219-1-3p were determined respectively, in glioblastoma multiforme (GBM) (n = 31), their adjacent normal tissues (n = 31), and GBM U87 cell line. Following treatment of GBM U87 cells with 5-aza-2 ′-deoxycitidine (5-aza-dC), miR-219-1 promoter met...
Source: Biochemistry (Moscow) - April 1, 2021 Category: Biochemistry Source Type: research

Rhodopsin Channel Activity Can Be Evaluated by Measuring the Photocurrent Voltage Dependence in Planar Bilayer Lipid Membranes
AbstractThe studies of the functional properties of retinal-containing proteins often include experiments in model membrane systems, e.g., measurements of electric current through planar bilayer lipid membranes (BLMs) with proteoliposomes adsorbed on one of the membrane surfaces. However, the possibilities of this method have not been fully explored yet. We demonstrated that the voltage dependence of stationary photocurrents for two light-sensitive proteins, bacteriorhodopsin (bR) and channelrhodopsin 2 (ChR2), in the presence of protonophore had very different characteristics. In the case of the bR (proton pump), the phot...
Source: Biochemistry (Moscow) - March 19, 2021 Category: Biochemistry Source Type: research

Characterization of Regulatory Elements of L11 and L1 Operons in Thermophilic Bacteria and Archaea
AbstractRibosomal protein L1 is a conserved two-domain protein that is involved in formation of the L1 stalk of the large ribosomal subunit. When there are no free binding sites available on the ribosomal 23S RNA, the protein binds to the specific site on the mRNA of its own operon (L11 operon in bacteria and L1 operon in archaea) preventing translation. Here we show that the regulatory properties of the r-protein L1 and its domain I are conserved in the thermophilic bacteriaThermus andThermotoga and in the halophilic archaeonHaloarcula marismortui. At the same time the revealed features of the operon regulation in thermop...
Source: Biochemistry (Moscow) - March 19, 2021 Category: Biochemistry Source Type: research

COVID-19 Pandemic and Male Fertility: Clinical Manifestations and Pathogenic Mechanisms
AbstractThe novel coronavirus disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been a major public health emergency worldwide with over 118.27-million confirmed COVID-19 cases and 2.62-million deaths recorded, as of March 12, 2021. Although this disease primarily targets lungs, damages in other organs, such as heart, kidney, liver, and testis, may occur. Testis is the cornerstone of male reproduction, while reproductive health is the most valuable resource for continuity of the human race. Given the unique nature of SARS-CoV-2, the mechanisms of its impact on the...
Source: Biochemistry (Moscow) - March 19, 2021 Category: Biochemistry Source Type: research

Molecular and Cellular Mechanisms of Respiratory Syncytial Viral Infection: Using Murine Models to Understand Human Pathology
AbstractRespiratory syncytial virus (RSV) causes severe pathology of the lower respiratory tract in infants, immunocompromised people, and elderly. Despite decades of research, there is no licensed vaccine against RSV, and many therapeutic drugs are still under development. Detailed understanding of molecular and cellular mechanisms of the RSV infection pathology can accelerate the development of efficacious treatment. Current studies on the RSV pathogenesis are based on the analysis of biopsies from the infected patients; however deeper understanding of molecular and cellular mechanisms of the RSV pathology could be achie...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Mitochondrial Antioxidant SkQ1 Improves Hypothermic Preservation of the Cornea
AbstractDiseases of the cornea are a frequent cause of blindness worldwide. Keratoplasty is an efficient method for treating severely damaged cornea. The functional competence of corneal endothelial cells is crucial for successful grafting, which requires improving the media for the hypothermic cornea preservation, as well as developing the methods for the evaluation of the corneal functional properties. The transport of water and ions by the corneal endothelium is important for the viability and optic properties of the cornea. We studied the impact of SkQ1 on the equilibrium sodium concentration in the endothelial cells a...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

AML-Associated Mutations in DNA Methyltransferase DNMT3A
AbstractIn mammals, DNA methylation is an essential epigenetic modification necessary for the maintenance of genome stability, regulation of gene expression, and other processes. Carcinogenesis is accompanied by multiple changes in the DNA methylation pattern and DNA methyltransferase (DNMT) genes; these changes are often associated with poor disease prognosis. Human DNA methyltransferase DNMT3A is responsible forde novo DNA methylation. Missense mutations in the DNMT3A gene occur frequently at the early stages of tumor development and are often observed in hematologic malignances, especially in acute myeloid leukemia (AML...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

On the Role of Normal Aging Processes in the Onset and Pathogenesis of Diseases Associated with the Abnormal Accumulation of Protein Aggregates
AbstractAging is a prime systemic cause of various age-related diseases, in particular, proteinopathies. In fact, most diseases associated with protein misfolding are sporadic, and their incidence increases with aging. This review examines the process of protein aggregate formation, the toxicity of such aggregates, the organization of cellular systems involved in proteostasis, and the impact of protein aggregates on important cellular processes leading to proteinopathies. We also analyze how manifestations of aging (mitochondrial dysfunction, dysfunction of signaling systems, changes in the genome and epigenome) facilitate...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Proteomics of Cellular Response to Stress: Taking Control of False Positive Results
AbstractOne of the main goals of quantitative proteomics is molecular profiling of cellular response to stress at the protein level. To perform this profiling, statistical analysis of experimental data involves multiple testing of a hypothesis about the equality of protein concentrations between the cells under normal and stress conditions. This analysis is then associated with the multiple testing problem dealing with the increased chance of obtaining false positive results. A number of solutions to this problem are known, yet, they may lead to the loss of potentially important biological information when applied with com...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Direct Effect of the Synthetic Analogue of Glucagon-Like Peptide Type 1, Liraglutide, on Mature Adipocytes Is Realized through Adenylate-Cyclase-Dependent Enhancing of Insulin Sensitivity
AbstractIncretin hormones analogues, including glucagon-like peptide type 1 (GLP-1), exhibit complex glucose-lowering, anorexigenic, and cardioprotective properties. Mechanisms of action of GLP-1 and its analogues are well known for pancreatic β-cells, hepatocytes, and other tissues. Nevertheless, local effects of GLP-1 and its analogues in adipose tissue remain unclear. In the present work effects of the GLP-1 synthetic analogue, liraglutide, on adipogenesis and insulin sensitivity of the 3T3-L1 adipocytes were examined. Enhancement of insulin sensitivity of mature adipocytes by the GLP-1 synthetic analogue liragluti...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Effect of Dynamic and Static Load on the Concentration of Myokines in the Blood Plasma and Content of Sodium and Potassium in Mouse Skeletal Muscles
AbstractModulation of cytokine production by physical activity is of considerable interest, since it might be a promising strategy for correcting metabolic processes at both cellular and systemic levels. The content of IL-6, IL-8, and IL-15 in the plasma and the concentration of monovalent cations in the skeletal muscles of trained and untrained mice were studied at different periods after static and dynamic exercises. Dynamic loads caused an increase in the IL-6 content and decrease in the IL-15 content in the plasma of untrained mice, but produced no effect on the concentration of IL-8. In trained mice, the effect of a s...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Upregulation of NOX-2 and Nrf-2 Promotes 5-Fluorouracil Resistance of Human Colon Carcinoma (HCT-116) Cells
AbstractAltered expression of cellular redox genes and proteins contributes to invasion, metastasis, and drug resistance in cancer. NADPH oxidase (NOX) isoforms are the pro-oxidant enzymes that generate ROS as a primary product. Dysregulation of NOX activity and expression alters ROS generation, which either directly or indirectly modulates cell death and survival signaling during the progression of cancer. Nuclear factor erythroid 2-related factor 2 (Nrf-2) is an inducible transcription factor, which transcribes an array of antioxidant genes and protects cancer cells from the oxidative stress. Both NOXs and Nrf-2 particip...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Microbial Arsenal of Antiviral Defenses – Part I
AbstractBacteriophages or phages are viruses that infect bacterial cells (for the scope of this review we will also consider viruses that infect Archaea). Constant threat of phage infection is a major force that shapes evolution of the microbial genomes. To withstand infection, bacteria had evolved numerous strategies to avoid recognition by phages or to directly interfere with phage propagation inside the cell. Classical molecular biology and genetic engineering have been deeply intertwined with the study of phages and host defenses. Nowadays, owing to the rise of phage therapy, broad application of CRISPR-Cas technologie...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Catalytic Properties of Flavocytochrome c Sulfide Dehydrogenase from Haloalkaliphilic Bacterium Thioalkalivibrio paradoxus
AbstractFlavocytochromec sulfide dehydrogenase (FCC) is one of the central enzymes of the respiratory chain in sulfur-oxidizing bacteria. FCC catalyzes oxidation of sulfide and polysulfide ions to elemental sulfur accompanied by electron transfer to cytochromec. The catalytically active form of the enzyme is a non-covalently linked heterodimer composed of flavin- and heme-binding subunits. TheThioalkalivibrio paradoxus ARh1 genome contains five copies of genes encoding homologous FCCs with an amino acid sequence identity from 36 to 54%. When growing on thiocyanate or thiosulfate as the main energy source, the bacterium syn...
Source: Biochemistry (Moscow) - March 1, 2021 Category: Biochemistry Source Type: research

Recombinant SARS-CoV-2 S Protein Binds to Glycans of the Lactosamine Family in vitro
AbstractMany viruses, beside binding to their main cell target, interact with other molecules that promote virus adhesion to the cell; often, these additional targets are glycans. The main receptor for SARS-CoV-2 is a peptide motif in the ACE2 protein. We studied interaction of the recombinant SARS-CoV-2 spike (S) protein with an array of glycoconjugates, including various sialylated, sulfated, and other glycans, and found that the S protein binds some (but not all) glycans of the lactosamine family. We suggest that parallel influenza infection will promote SARS-CoV-2 adhesion to the respiratory epithelial cells due to the...
Source: Biochemistry (Moscow) - February 25, 2021 Category: Biochemistry Source Type: research

Klotho Protein and Cardio-Vascular System
AbstractKlotho protein affects a number of metabolic pathways essential for pathogenesis of cardio-vascular diseases and their prevention. It inhibits lipid peroxidation and inflammation, as well as prevents endothelial injury and calcification of blood vessels. Klotho decreases rigidity of blood vessels and suppresses development of the heart fibrosis. Low level of its expression is associated with a number of diseases. Cardioprotective effect of klotho is based on its ability to interact with multiple receptors and ion channels. Being a pleiotropic protein, klotho could be a useful target for therapeutic intervention in ...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Hepatoprotective Effects of Polydatin-Loaded Chitosan Nanoparticles in Diabetic Rats: Modulation of Glucose Metabolism, Oxidative Stress, and Inflammation Biomarkers
AbstractPolydatin (PD) has a broad range of pharmacological activities; however, its effects on diabetic liver damage are poorly studies. This work is aimed to explore possible protective effects of polydatin-loaded chitosan nanoparticles (PD-CSNPs) or PD against liver damage associated with diabetes. Diabetes was induced in rats using nicotinamide/streptozotocin treatment. Diabetic rats were then divided into six groups: normal control rats, diabetic control rats, and rats orally treated with PD, PD-CSNPs, equivalent unloaded CSNPs, or metformin daily for 4 weeks. Treatment with PD and PD-CSNPs significantly reduced the b...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Humoral Effect of a B-Cell Tumor on the Bone Marrow Multipotent Mesenchymal Stromal Cells
AbstractThe properties of bone marrow (BM)-derived multipotent mesenchymal stromal cells (MSCs) are altered in the patients with the diffuse large B cell lymphoma (DLBCL) without BM involvement. It was suggested that plasma from the patients contains soluble factors that affect MSCs. Plasma and BM-derived MSCs from the DLBCL patients at the onset of the disease and one month after the end of treatment were studied. Concentration of the plasma cytokines and gene expression in the MSCs were evaluated by the Bio-Plex Pro Human Cytokine Panel kit to measure 27 analytes and real-time PCR. Plasma and MSCs from the healthy donors...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Glucocorticoids: Dr. Jekyll and Mr. Hyde of Hippocampal Neuroinflammation
AbstractGlucocorticoids (GCs) are an important component of adaptive response of an organism to stressogenic stimuli, a typical stress response being accompanied by elevation of GC levels in blood. Anti-inflammatory effects of GCs are widely used in clinical practice, while pro-inflammatory effects of GCs are believed to underlie neurodegeneration. This is particularly critical for the hippocampus, brain region controlling both cognitive function and emotions/affective behavior, and selectively vulnerable to neuroinflammation and neurodegeneration. The hippocampus is believed to be the main target of GCs since it has the h...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

The Role of P-Glycoprotein in Decreasing Cell Membranes Permeability during Oxidative Stress
In this study, we investigated the role of P-gp in limiting the cell membrane permeability during oxidative stress. Human adenocarcinoma colon cells (Caco-2) overexpressing P-gp were cultured for 72 h in the medium containing hydrogen peroxide (0.1-50 µM). The transport of the P-gp substrate fexofenadine was evaluated in a special Transwell system. The amounts of P-gp and Nrf2 transcription factor were analyzed by the enzyme-linked immunosorbent assay. The concentration of SH-groups in proteins and the contents of lipid peroxidation products and protein carbonyl derivatives were determined spectrophotometrically. Hyd...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

The Structure of the Potato Virus A Particles Elucidated by Small Angle X-Ray Scattering and Complementary Techniques
AbstractPotato virus A (PVA) protein coat contains on its surface partially unstructured N-terminal domain of the viral coat protein (CP), whose structural and functional characteristics are important for understanding the mechanism of plant infection with this virus. In this work, we investigated the properties and the structure of intact PVA and partially trypsinized PVA Δ32 virions using small-angle X-ray scattering (SAXS) and complimentary methods. It was shown that after the removal of 32 N-terminal amino acids of the CP, the virion did not disintegrate and remained compact, but the helical pitch of the CP packi...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Levels of Zinc Transporters mRNA Depending on Zinc Status and HIV-1 Tat Induced Inflammation in Muscle (Rhabdomyosarcoma) and Monocyte (THP-1) Cell Lines
AbstractMonocytes and muscles demonstrate functionally contrasting behavior under conditions of zinc deficiency with relation to zinc storage system (muscle retain zinc in contrast to monocytes). We aimed to understand the effects of zinc status and HIV-1 Tat mediated inflammation on expression of zinc transporters in these types of cells. Expression of zinc transporters [ZnTs, ZIPs, and metallothionein (MT)] was quantified by qRT-PCR in RD, THP-1 cells separately and in co-cultured THP-1 –RD cells. ZnT1 protein expression levels were confirmed by Western blot. Significant increase of MT and ZnT1 mRNA in response to ...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

The Mechanisms of L-Arginine Metabolism Disorder in Endothelial Cells
AbstractL-arginine is a key metabolite for nitric oxide production by endothelial cells, as well as signaling molecule of the mTOR signaling pathway. mTOR supports endothelial cells homeostasis and regulates activity of L-arginine-metabolizing enzymes, endothelial nitric oxide synthase, and arginase II. Disruption of the L-arginine metabolism in endothelial cells leads to the development of endothelial dysfunction. Conflicting results of the use of L-arginine supplement to improve endothelial function reveals a controversial role of the amino acid in the endothelial cell biology. The review is aimed at analysis of the curr...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Enhanced Solubility and One-Step Purification of Functional Dimeric Carboxypeptidase G2
AbstractCarboxypeptidase G2 is a bacterial enzyme that catalyzes methotrexate conversion to its inactive forms which are then eliminated via a non-renal pathway in patients with renal disorders during a high-dose methotrexate administration. Due to the increasing demand of this enzyme, it was of interest to simplify its production process. For this reason, we developed a method for production and one-step purification of this enzyme using an intein-mediated system with a chitin-binding affinity tag. The carboxypeptidase G2 gene fromPseudomonas RS16 was optimized, synthesized, cloned into the pTXB1 expression vector and fin...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

CRABP1 and CRABP2 Protein Levels Correlate with Each Other but Do Not Correlate with Sensitivity of Breast Cancer Cells to Retinoic Acid
AbstractRetinoic acid (RA) binding proteins, CRABP1 and CRABP2, are molecular chaperones that mediate intracellular activity of RA, the key promoter of cell differentiation with tumor suppressor activity. One of the main functions of CRABP2 is delivery and transfer of RA to the nuclear receptors RAR/RXR, which leads to activation of the transcription of a wide range of retinoid-responsive genes. The functions of CRABP1 are less studied but are apparently associated with sequestration of RA in cytoplasm and limitation of its transcriptional activity, suggesting involvement of this protein in the development of RA resistance...
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Erratum to: The Problem of Apoptotic Processes Reversibility
On p. 1157, “Funding” section: instead of “project no. 19-015-0023” should read “project no. 19-015-00233”. (Source: Biochemistry (Moscow))
Source: Biochemistry (Moscow) - February 1, 2021 Category: Biochemistry Source Type: research

Bioconversion of Renewable Plant Biomass. Second-Generation Biofuels: Raw Materials, Biomass Pretreatment, Enzymes, Processes, and Cost Analysis
AbstractThe review discusses various aspects of renewable plant biomass conversion and production of the second-generation biofuels, including the types of plant biomass, its composition and reaction ability in the enzymatic hydrolysis, and various pretreatment methods for increasing the biomass reactivity. Conversion of plant biomass into sugars requires the use of a complex of enzymes, the composition of which should be adapted to the biomass type and the pretreatment method. The efficiency of enzymatic hydrolysis can be increased by optimizing the composition of the enzymatic complex and by increasing the catalytic acti...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Diversity of LSM Family Proteins: Similarities and Differences
AbstractMembers of the Lsm protein family are found in all three domains of life: bacteria, archaea, and eukarya. They are involved in numerous processes associated with RNA processing and gene expression regulation. A common structural feature of all Lsm family proteins is the presence of the Sm fold consisting of a five-stranded β-sheet and an α-helix at the N-terminus. Heteroheptameric eukaryotic Sm and Lsm proteins participate in the formation of spliceosomes and mRNA decapping. Homohexameric bacterial Lsm protein, Hfq, is involved in the regulation of transcription of different mRNAs by facilitating their i...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Metallo- β-Lactamases: Influence of the Active Site Structure on the Mechanisms of Antibiotic Resistance and Inhibition
AbstractThe review focuses on bacterial metallo- β-lactamases (MβLs) responsible for the inactivation of β-lactams and associated antibiotic resistance. The diversity of the active site structure in the members of different MβL subclasses explains different mechanisms of antibiotic hydrolysis and should be taken into account when searching for potential MβL inhibitors. The review describes the features of the antibiotic inactivation mechanisms by various MβLs studied by X-ray crystallography, NMR, kinetic measurements, and molecular modeling. The mechanisms of enzyme inhibition for each M&beta...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Terminal Oxidase Cytochrome bd Protects Bacteria Against Hydrogen Sulfide Toxicity
AbstractHydrogen sulfide (H2S) is often called the third gasotransmitter (after nitric oxide and carbon monoxide), or endogenous gaseous signaling molecule. This compound plays important roles in organisms from different taxonomic groups, from bacteria to animals and humans. In mammalian cells, H2S has a cytoprotective effect at nanomolar concentrations, but becomes cytotoxic at higher concentrations. The primary target of H2S is mitochondria. At submicromolar concentrations, H2S inhibits mitochondrial heme-copper cytochromec oxidase, thereby blocking aerobic respiration and oxidative phosphorylation and eventually leading...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

The Mechanisms of Electrogenic Reactions in Bacterial Photosynthetic Reaction Centers: Studies in Collaboration with Alexander Konstantinov
AbstractIn this review, we discuss our studies conducted in 1985-1988 in collaboration with A. A. Konstantinov, one of the top scientists in the field of membrane bioenergetics. Studying fast kinetics of membrane potential generation in photosynthetic reaction centers (RCs) of purple bacteria in response to a laser flash has made it possible to examine in detail the mechanisms of electrogenic reactions at the donor and acceptor sides of RCs. Electrogenesis associated with the intraprotein electron transfer from the exogenous secondary donors, redox dyes, and soluble cytochrome (cyt)c to the photooxidized dimer of bacterioc...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Mechanism of Inhibition of Cytochrome c Oxidase by Triton X-100
AbstractIt is known that Triton X-100 (TX) reversibly inhibits activity of cytochromec oxidase (CcO). The mechanism of inhibition is analyzed in this work. The action of TX is not directed to the reaction of CcO with cytochromec, does not cause transition of the enzyme to the “slow” form, and is not associated with monomerization of the enzyme complex. TX completely suppresses oxygen reduction by CcO, but inhibition is prevented and partially reversed by dodecyl-β–D-maltoside (DDM), a detergent used to maintain CcO in solution. A 1/1 stoichiometry competition is s hown between DDM and TX for binding ...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Structural and Functional Aspects of Electron Transport Thermoregulation and ATP Synthesis in Chloroplasts
AbstractThe review is focused on analysis of the mechanisms of temperature-dependent regulation of electron transport and ATP synthesis in chloroplasts of higher plants. Importance of photosynthesis thermoregulation is determined by the fact that plants are ectothermic organisms, whose own temperature depends on the ambient temperature. The review discusses the effects of temperature on the following processes in thylakoid membranes: (i) photosystem 2 activity and plastoquinone reduction; (ii) electron transfer from plastoquinol (via the cytochromeb6f complex and plastocyanin) to photosystem 1; (iii) transmembrane proton t...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Molecular and Functional Effects of Loss of Cytochrome c Oxidase Subunit 8A
AbstractIn this work we studied molecular and functional effects of the loss of the smallest nuclear encoded subunit of cytochromec oxidase COX8A in fibroblasts from a patient with a homozygous splice site mutation and in CRISPR/Cas9 genome-edited HEK293T cells. In both cellular model systems, between 20 to 30% of the residual enzymatic activity of cytochromec oxidase (COX) was detectable. In immunoblots of BN-PAGE separated mitochondria from both cellular models almost no monomers and dimers of the fully assembled COX could be visualized. Interestingly, supercomplexes of COX formed with complex III and also with complexes...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

The Enigma of 2-Cys Peroxiredoxins: What Are Their Roles?
Abstract2-Cys peroxiredoxins are abundant thiol proteins that react efficiently with a wide range of peroxides. Unlike other enzymes, their exceptionally high reactivity does not rely on cofactors. The mechanism of oxidation and reduction of peroxiredoxins places them in a good position to act as antioxidants as well as key players in redox signaling. Understanding of the intimate details of peroxiredoxin functioning is important for translational research. (Source: Biochemistry (Moscow))
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Thermodynamics of the P-type Ferryl Form of Bovine Cytochrome c Oxidase
AbstractSeveral ferryl states of the catalytic hemea3-CuB center of the respiratory cytochromec oxidases (CcOs) are observed during the reduction of O2 to H2O. One of theP-type ferryl forms,PM, is produced by the reaction of the two-electron reduced CcO with O2. In this state, the hemea3 iron is in the ferryl state and a free radical should be also present at the catalytic center. However, the energetics of thePM formation has not been experimentally established yet. Here, the generation ofPM by the reaction of oxidized bovine CcO (O) with one molecule of H2O2 was investigated by the isothermal titration calorimetry and UV...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Time-Resolved Electrometric Study of the F →O Transition in Cytochrome c Oxidase. The Effect of Zn 2+ Ions on the Positive Side of the Membrane
AbstractThe effect of Zn2+ on the P-side of proteoliposomes containing membrane-incorporatedRhodobacter sphaeroides cytochromec oxidase was investigated by the time-resolved electrometrics following a single electron injection into the enzyme prepared in the F state. The wild-type enzyme was examined along with the two mutants, N139D and D132N. All obtained data indicate that the primary effect of Zn2+ added from the P-side of the membrane is slowing of the pumped proton release from the proton loading site (PLS) to the bulk aqueous phase on the P-side of the membrane. The results strongly suggest the presence of two pathw...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Molecular Biology of Bacillus subtilis Cytochromes anno 2020
AbstractBacillus subtilis serves as a model Gram-positive bacterium and an experimental system for research on respiratory enzymes. This review presents the heme proteins currently known for the well-characterized laboratory strainB. subtilis 168. It focuses on advances in research made during the last three decades concerning the function and composition of the cytochromebc complex, terminal oxidases, and succinate:menaquinone oxidoreductase. The aerobic respiratory system of strain 168 seems representative for the speciesB. subtilis, as determined by the cytochrome composition of the undomesticated strainB. subtilis NCIB...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

Anion-Specific Effects on the Alkaline State of Cytochrome c
AbstractSpecific effects of anions on the structure, thermal stability, and peroxidase activity of native (state III) and alkaline (state IV) cytochromec (cytc) have been studied by the UV-VIS absorbance spectroscopy, intrinsic tryptophan fluorescence, and circular dichroism. Thermal and isothermal denaturation monitored by the tryptophan fluorescence and circular dichroism, respectively, implied lower stability of cytc state IV in comparison with the state III. The pKa value of alkaline isomerization of cytc depended on the present salts, i.e., kosmotropic anions increased and chaotropic anions decreased pKa (Hofmeister e...
Source: Biochemistry (Moscow) - January 1, 2021 Category: Biochemistry Source Type: research

The Use of Fluorescently Labeled ARC1779 Aptamer for Assessing the Effect of H 2 O 2 on von Willebrand Factor Exocytosis
AbstractHere, we propose a new approach for quantitative estimation of von Willebrand factor (vWF) exposed on the surface of endothelial cells (ECs) using the ARC1779 aptamer that interacts with the vWF A1 domain. To visualize complex formation between vWF and the aptamer, the latter was conjugated with the Cy5 fluorescent label. Cultured human umbilical vein endothelial cells (HUVEC) were stained with the ARC1779-Cy5 conjugate and imaged with a fluorescence microscope. The images were analyzed with the CellProfiler software. vWF released from the Weibel –Palade bodies was observed as bright dot-like structures of ro...
Source: Biochemistry (Moscow) - December 31, 2020 Category: Biochemistry Source Type: research