Polymorphism of delta3,5-delta2,4-dienoyl-coenzyme A isomerase (the ECH1 gene product protein) in human striated muscle tissue

Mitochondrial ATP Synthase and Mild Uncoupling by Butyl Ester of Rhodamine 19, C4R1

The homeostasis of the transmembrane potential of hydrogen ions in mitochondria is a prerequisite for the normal mitochondrial functioning. However, in different pathological conditions it is advisable to slightly reduce the membrane potential, while maintaining it at levels sufficient to produce ATP that will ensure the normal functioning of the cell. A number of chemical agents have been found to provide mild uncoupling; however, natural proteins residing in mitochondrial membrane can carry this mission, such as proteins from the UCP family, an adenine nucleotide translocator and a dicarboxylate carrier. In this study, we demonstrated that the butyl ester of rhodamine 19, C4R1, binds to the components of the mitochondrial ATP synthase complex due to electrostatic interaction and has a good uncoupling effect. The more hydrophobic derivative C12R1 binds poorly to mitochondria with less uncoupling activity. Mass spectrometry confirmed that C4R1 binds to the β-subunit of mitochondrial ATP synthase and based on molecular docking, a C4R1 binding model was constructed suggesting the binding site on the interface between the α- and β-subunits, close to the anionic amino acid residues of the β-subunit. The association of the uncoupling effect with binding suggests that the ATP synthase complex can provide induced uncoupling.

Adaptation of two-dimensional electrophoresis for muscle tissue analysis

It is important to understand the molecular mechanisms that take place in muscle tissues and to predict meat quality characteristics. One of the most popular methods is two-dimensional electrophoresis, which allows us to visualize, share and identify different molecules, including meat proteins. However, the standard conditions of this method are not universal for all types of raw material, so the authors suggest a new variation of two-dimensional electrophoresis for muscle tissue analysis. Samples were tested by the classical version of isoelectric focusing (cathode buffer in the top and anode buffer in the bottom chamber of the electrophoresis cell) and its variation (anode buffer in the top and cathode buffer in the bottom chamber of the electrophoresis cell). Next, extruded gels were incubated in two different buffer systems: the first was equilibration buffer I (6 M urea, 20% w/v glycerol, 2% w/v SDS and 1% w/v Ditiothreitol in 375 mM Tris-HCl buffer, pH 8.8) followed by equilibration buffer II (6 M urea, 20% w/v glycerol, 2% w/v SDS and 4% w/v iodoacetamide in 375 mM Tris-HCl buffer pH 8.8 and the second, buffer А, consisting of 5 M urea, 2% w/v SDS, 5% v/v mercaptoethanol, 62.5 mM Tris-HCl buffer, pH 6.8 and 0.01% w/v bromophenol blue. Electrophoretic studies of muscle tissue revealed the best protein separation after changing the direction of the current (authors' variation), while no differences were detected after changing incubation buffers.

Influence of technological processing on lipid-lowering activity of substances containing in porcine hearts and aortas

Edible by-products are a good source of nutrients and bioactive substances and could be used as functional ingredients or for biopeptides production natively contained in raw materials. A wide range of peptides are also formed during the enzymatic hydrolysis or food processing. The comparative results of the effectiveness of isolated certain protein and peptide fractions by ultrafiltration with the same natively presented in raw tissues, as well as the influence of heat treatment on biological activity of origin active substances are presented. The model of rat alimentary hyperlipidemia was developed by adding cholesterol and fat to the standard diet and vitamin D2 injection per os. Serum lipid profile was determined on automatic analyzer BioChem FC-360. Dynamic of changes in serum lipid profile was assessed as corresponding control group medium results in ratio to certain rat data. Two-dimensional electrophoresis (2DE) was performed according to the method of O’Farrell with isoelectric focusing in ampholine pH gradient (IEF-PAGE) with following identification by MALDI-TOF MS and MS/MS mass spectrometry. Consumption of native pig aorta and pig heart during 14th days led to normalization of lipid profile in serum of hyperlipidemic rats, while low molecular weight (LMUF, MW <5 kDa) and medium molecular weight (MMUF, MW = 5 – 30 kDa) ultrafiltrates of pig aorta extract did not strongly influenced on level of triglicerides and, on contrary, elevated high density cholesterol. Consumption of developed product by hyperlipidemic rats during 28th days did not lead to significant changes in serum lipid profile, while on 42nd day all ratios reached ones in group, which were treated with native raw material or isolated active fractions. The stability of developed product was confirmed by proteomic studies. Obtained results open prospects to modernization the technology, presumably use as a matrix dietary meat (e.g. poultry) with incorporated active identified components.

Human COQ10A and COQ10B are distinct lipid-binding START domain proteins required for coenzyme Q function

Coenzyme Q (CoQ or ubiquinone) serves as an essential redox-active lipid in respiratory electron and proton transport during cellular energy metabolism. CoQ also functions as a membrane-localized antioxidant protecting cells against lipid peroxidation. CoQ deficiency is associated with multiple human diseases; CoQ₁₀ supplementation in particular has noted cardioprotective benefits. In Saccharomyces cerevisiae, Coq10, a putative START domain protein, is believed to chaperone CoQ to sites where it functions. Yeast coq10 deletion mutants (coq10Δ) synthesize CoQ inefficiently during log phase growth and are respiratory defective and sensitive to oxidative stress. Humans have two orthologs of yeast COQ10, COQ10A and COQ10B Here, we tested the human co-orthologs for their ability to rescue the yeast mutant. We showed that expression of either human ortholog, COQ10A or COQ10B, rescues yeast coq10Δ mutant phenotypes, restoring the function of respiratory-dependent growth on a nonfermentable carbon source and sensitivity to oxidative stress induced by treatment with PUFAs. These effects indicate a strong functional conservation of Coq10 across different organisms. However, neither COQ10A nor COQ10B restored CoQ biosynthesis when expressed in the yeast coq10Δ mutant. The involvement of yeast Coq10 in CoQ biosynthesis may rely on its interactions with another protein, possibly Coq11, which is not found in humans. Coexpression analyses of yeast COQ10 and human COQ10A and COQ10B provide additional insights to functions of these START domain proteins and their potential roles in other biologic pathways.

Bovine mucous membranes as a source of antimicrobial compounds

Loss of food quality, deterioration of organoleptic properties and accumulation of anti-alimentary compounds are in focus of modern food science. Nowadays, such traditional methods as processing, physical and chemical treatment are used for improving of shelf life. An alternative ways of shelf life increasing are quite a sharp problem. Antimicrobial peptides (AMPs) could be an actual alternative. According to Antimicrobial Peptide Database (http://aps.unmc.edu/AP/main.php), 2884 antimicrobial peptides from six kingdoms were found and identified. Mucous membranes of farm animals due to their border position and intensive contact with different pathogens could be a capacious source of such substances. Objects of the study were bovine oral cavity mucosa, nasal cavity mucosa, tracheal cavity mucosa, rectal mucosa, tongue mucosa, saliva gland and submandibular lymph nodes. Two-dimensional electrophoresis (2DE) was performed according to the method of O'Farrell, 35 protein fractions were identified by MALDI-TOF MS and MS/MS mass spectrometry. A number of qualitative and quantitative differences were revealed. A large number of histones (H2bd-like, H2BC, HIST1H2BD, HIST2H2AC, HIST1H2AH, histone H3.3 and H2bl-like, HIST2H2AC and histone H3.3, mixture HIST1H2AJ, HIST2H2BE and histone H2A type 2-C) were found in all mucous membranes as well as several tissue-specific proteins (proteins S100-A12 and AGR2, isoforms of ribosomal proteins, myelin P2, odorant-binding protein, secretoglobin), which could be a precusors of bioactive peptides

Glutamate contributes to alcohol hepatotoxicity by enhancing oxidative stress in mitochondria

Chronic alcohol intoxication is associated with increased oxidative stress. However, the mechanisms by which ethanol triggers an increase in the production of reactive oxygen species (ROS) and the role of mitochondria in the development of oxidative stress has been insufficiently studied. The biochemical and proteomic data obtained in the present work suggest that one of the main causes of an increase in ROS generation is enhanced oxidation of glutamate in response to long-term alcohol exposure. In the course of glutamate oxidation, liver mitochondria from alcoholic rats generated more superoxide anion and H₂O₂ than in the presence of other substrates and more than control organelles. In mitochondria from alcoholic rats, rates of H₂O₂ production and NAD reduction in the presence of glutamate were almost twice higher than in the control. The proteomic study revealed a higher content of glutamate dehydrogenase in liver mitochondria of rats subjected to chronic alcohol exposure. Simultaneously, the content of mitochondrial catalase decreased compared to control. Each of these factors stimulates the production of ROS in addition to ROS generated by the respiratory chain complex I. The results are consistent with the conclusion that glutamate contributes to alcohol hepatotoxicity by enhancing oxidative stress in mitochondria.

Mitochondrial alterations and oxidative stress in an acute transient mouse model of muscle degeneration: implications for muscular dystrophy and related muscle pathologies

Muscular dystrophies (MDs) and inflammatory myopathies (IMs) are debilitating skeletal muscle disorders characterized by common pathological events including myodegeneration and inflammation. However, an experimental model representing both muscle pathologies and displaying most of the distinctive markers has not been characterized. We investigated the cardiotoxin (CTX)-mediated transient acute mouse model of muscle degeneration and compared the cardinal features with human MDs and IMs. The CTX model displayed degeneration, apoptosis, inflammation, loss of sarcolemmal complexes, sarcolemmal disruption, and ultrastructural changes characteristic of human MDs and IMs. Cell death caused by CTX involved calcium influx and mitochondrial damage both in murine C2C12 muscle cells and in mice. Mitochondrial proteomic analysis at the initial phase of degeneration in the model detected lowered expression of 80 mitochondrial proteins including subunits of respiratory complexes, ATP machinery, fatty acid metabolism, and Krebs cycle, which further decreased in expression during the peak degenerative phase. The mass spectrometry (MS) data were supported by enzyme assays, Western blot, and histochemistry. The CTX model also displayed markers of oxidative stress and a lowered glutathione reduced/oxidized ratio (GSH/GSSG) similar to MDs, human myopathies, and neurogenic atrophies. MS analysis identified 6 unique oxidized proteins from Duchenne muscular dystrophy samples (n = 6) (versus controls; n = 6), including two mitochondrial proteins. Interestingly, these mitochondrial proteins were down-regulated in the CTX model thereby linking oxidative stress and mitochondrial dysfunction. We conclude that mitochondrial alterations and oxidative damage significantly contribute to CTX-mediated muscle pathology with implications for human muscle diseases.

Proteomic analysis of human skeletal muscle (m. vastus lateralis) proteins: identification of 89 gene expression products

Proteins from bioptates and autoptates of human skeletal muscle m. vastus lateralis were separated by O'Farrell two-dimensional gel electrophoresis (2DE). MALDI-TOF MS and MS/MS enabled identification of 89 protein spots as expression products of 55 genes. A modification of the O'Farrell's method including non-equilibrium electrophoresis in a pH gradient allowed detection--among major sarcomeric, mitochondrial, and cytosolic proteins--of several proteins, such as PDZ- and LIM domain-containing ones (pI > 8.70), fragments of known proteins, and a stable complex of heavy and light ferritin chains. The data underlie further studies of human skeletal muscle proteins in terms of molecular mechanisms of some physiological and pathological processes.