Vladimir A. Serezhenkov
Semenov Institute of Chemical Physics
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Featured researches published by Vladimir A. Serezhenkov.
Biochemical Journal | 2005
Sergey Shleev; Andreas Christenson; Vladimir A. Serezhenkov; Dosymzhan Sh. Burbaev; A. I. Yaropolov; Lo Gorton; Tautgirdas Ruzgas
Mediatorless, electrochemically driven, redox transformations of T1 (type 1) and T2 copper sites in Trametes hirsuta laccase were studied by cyclic voltammetry and spectroelectrochemical redox titrations using bare gold electrode. DET (direct electron transfer) between the electrode and the enzyme was observed under anaerobic conditions. From analysis of experimental data it is concluded that the T2 copper site is in DET contact with gold. It was found that electron transfer between the gold surface and the T1 copper site progresses through the T2 copper site. From EPR measurements and electrochemical data it is proposed that the redox potential of the T2 site for high-potential blue laccase is equal to about 400 mV versus NHE (normal hydrogen electrode) at pH 6.5. The hypothesis that the redox potentials of the T2 copper sites in low- and high-potential laccases/oxidases from totally different sources might be very similar, i.e. approx. 400 mV, is discussed.
Nitric Oxide | 2013
Rostislav R. Borodulin; Lyudmila N. Kubrina; Vladimir A. Serezhenkov; Dosymzhan Sh. Burbaev; Vasak D. Mikoyan; Anatoly F. Vanin
Using the electron paramagnetic resonance (EPR) and optical spectrophotometric methods, it has been established that biologically active, water-soluble dinitrosyl iron complexes (DNIC) with glutathione are predominantly represented by the diamagnetic binuclear form (B-DNIC) even in the presence of a 10-fold excess of glutathione non-incorporated into DNIC at neutral pH. With the increase in рН to 10-11, B-DNIC are fully converted into the paramagnetic mononuclear form (М-DNIC) with a characteristic EPR signal at g⊥=2.04, g‖=2.014 and gaver.=2.03. After treatment with a strong reducing agent sodium dithionite, both М- and B-DNIC are converted into the paramagnetic form with a characteristic EPR signal at g⊥=2.01, g‖=1.97 and gaver.=2.0. Both forms display similar absorption spectra with absorption bands at 960 and 640nm and a bend at 450nm. After oxidation by atmospheric oxygen, this situation is reversed, which manifests itself in the disappearance of the EPR signal at gaver.=2.0 and complete regeneration of initial absorption spectra of М- or B-DNIC with characteristic absorption bands at 390 or 360 and 310nm, respectively. Treatment of bovine serum albumin (BSA) solutions with gaseous NO in the presence of Fe(2+) and cysteine yields BSA-bound М-DNIC (М-DNIC-BSA). After treatment with sodium dithionite, the latter undergo transformations similar to those established for low-molecular М-DNIC with glutathione. Based on the complete coincidence of the optical and the EPR characteristics of sodium dithionite-treated М- and B-DNIC and other findings, it is suggested that sodium dithionite-reduced B-DNIC are subject to reversible decomposition into М-DNIC. The reduction and subsequent oxidation of М- and B-DNIC are interpreted in the paradigm of the current concepts of the initial electronic configurations of М- and B-DNIC (d(7) ({Fe(NO)2}(7)) and d(7)-d(7) ({Fe(NO)2}(7)-{Fe(NO)2}(7)), respectively).
Biophysics | 2007
A. B. Shekhter; T. G. Rudenko; Vladimir A. Serezhenkov; Anatoly F. Vanin
Dimeric dinitrosyl iron complexes (DNIC) with cysteine or glutathione as NO donors accelerated the healing of experimental skin wound in rats, as demonstrated by histological and histochemical examination. After two injections of an aqueous DNIC solution into the wound (total 5 μmol) on days 1 and 2 after surgery, the granulocyte volume in wound tissue on day 4 was 3–4 times greater than in the control. Higher DNIC doses provoked inflammation in the wound. Similar experiments with another NO donor S-nitrosoglutathione in equivalent amounts (10 μmol) adversely affected the wound. Addition of 2.5 μmol glutathione DNIC for 40 min produced EPR-detectable protein-bound DNIC (2.5 nmol) in wound tissue. Under the same conditions, 5 μmol S-nitrosoglutathione produced less than 10 pmol of protein-bound DNIC; an EPR-active nitrosyl hemoglobin complex was mainly formed (1.5–2.0 nmol) in this case. The beneficial effect of DNIC on the wound was suggested to be due to the delivery of NO to its targets without pronounced formation of cytotoxic peroxynitrite in wound tissue. In contrast, peroxynitrite could form upon administration of rapidly decomposed S-nitrosoglutathione, thereby aggravating the wound condition.
Biochemistry | 2005
O. V. Nikitina; Sergey Shleev; E. S. Gorshina; T. V. Rusinova; Vladimir A. Serezhenkov; D.Sh. Burbaev; L. V. Belovolova; A. I. Yaropolov
A method for purification of enzymes from the ligninolityc complex of the basidiomycete Trametes pubescens (Schumach.) Pilat has been elaborated. Two homogeneous isoforms of laccases (laccase 1 and laccase 2) as well as a homogeneous preparation of lignin peroxidase were isolated. Basic biochemical parameters of the enzymes were determined, such as the molecular weights (67, 67, and 45 kD, respectively), isoelectric points (5.3, 5.1, and 4.2, respectively), as well as content and composition of the carbohydrate moiety of the laccases (N-acetylglucosamine, mannose, and xylose). The pH dependences and thermal stabilities of the laccases were investigated. The kinetic parameters of the enzymatic reactions catalyzed by the laccases were determined using different substrates, such as catechol, hydroquinone, 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate), and K4Fe(CN)6. The structure of the active sites of both laccases and the lignin peroxidase were studied by EPR, CD, and UV-VIS spectroscopy, as well as using fluorescence analysis. Our studies showed similarity of the spectral characteristics of the two laccases, whereas their kinetic properties were found to be different.
Nitric Oxide | 2008
Vladimir A. Serezhenkov; Alexander A. Timoshin; Tsvetina R. Orlova; Vasak D. Mikoyan; Lioudmila N. Kubrinа; Alexander P. Poltorakov; Ruuge Ek; Natalia A. Sanina; Anatoly F. Vanin
EPR studies have shown that water-soluble mononitrosyl iron complexes with N-methyl-d-glucamine dithiocarbamate (MNIC-MGD) (3 micromol) injected to intact mice were decomposed virtually completely within 1h. The total content of MNIC-MGD in animal urine did not exceed 30 nmol/ml. In the liver, a small amount of MNIC-MGD were converted into dinitrosyl iron complexes (30 nmol/g of liver tissue). The same was observed in intact rabbits in which MNIC-MGD formation was induced by endogenous or exogenous NO binding to NO traps, viz., iron complexes with MGD. In mice, the content of MNIC-MGD in urine samples did not change after bacterial lipopolysaccharide-induced expression of iNOS. It was supposed that MNIC-MGD decomposition in intact animals was largely due to the release of NO from the complexes and its further transfer to other specific acceptors. In mice with iNOS expression, the main contribution to MNIC-MGD decomposition was made by superoxide ions whose destructive effect is mediated by an oxidative mechanism. This effect could fully compensate the augmented synthesis of MNIC-MGD involving endogenous NO whose production was supported by iNOS. Water-soluble dinitrosyl iron complexes (DNIC) with various thiol-containing ligands and thiosulfate injected to intact mice were also decomposed; however, in this case the effect was less pronounced than in the case of MNIC-MGD. It was concluded that DNIC decomposition was largely due to the oxidative effect of superoxide ions on these complexes.
Doklady Biochemistry and Biophysics | 2002
S. V. Vasil'eva; A. M. Malashenko; Lyudmila N. Kubrina; Anatoly F. Vanin; Vladimir A. Serezhenkov
Nitric oxide is involved in the immune response of the body, which is an extremely important biological function of this compound. At the initial stage of the immune response, activated macrophages produce highly toxic nitric oxide, which suppresses the resistance of bacteria, viruses, and other invasive microorgansims. The cytotoxic and cytostatic effects of nitric oxide are accounted for by its ability to inhibit the respiratory-chain key enzymes and the DNA synthesis in the target cells [1, 2]. In animals and plants, nitric oxide is synthesized by the constitutive and inducible forms of NO synthases (NOSs) from the amino acid L-arginine. Numerous experimental evidence on the location of both constitutive and inducible NOSs, their specific regulation, activity, and functions has been obtained mostly at the cellular level [3]. However, to our knowledge, it had never been shown that the immune status of animals from isogenic lines differing in the activity of only one gene was directly associated with the level of nitric oxide synthesized in immunocompetent organs in pathology. In this study, the content of nitric oxide in the liver and intestine of mice with identified genotypes were compared under the conditions of a model inflammatory process caused by injection of lipopolysaccharide from the E. coli cell wall. Mice of the inbred line C57BL/10SnY (B 10) (control) and those of two mutant lines, C57BL/10-hr rhy (Rhino) and NZB/Orly (NZB), were used in this study. The hairless ( hr ) gene mutation is characterized by pleiotropic effects, including immune disorders. The incidence of leukemia in the HRS mice homozygous for the hr mutation is higher than in their normal sibs. HRS mice exhibit a decreased cellular immune response against sheep red blood cells [4]. In 1984, a new hr gene mutation referred to as rhino-Y was detected in B10.R109 mice in the Laboratory of Experimental Biological Models, Russian Academy of Medical Sciences. A lack of hairs and a coarse skin rugosity increasing with age are characteristic traits of the mutant phenotype. The mutant females are completely infertile, and the males lose their fertility beginning from the age of four to five months [5]. In these animals, an immune pathology condition develops that is accompanied by deposition of immune complexes in the skin, muscles, kidney, and thymus. Visible morphological changes were the following: increased lymph nodes and a reduced thymus, a complete involution of which was sometimes observed by the age of six to eight months. The nature of the rhino-Y mutation is now known and the mutation has been shown to cause similar pathological disorders in mice and humans [6, 7]. The NZB mouse line is generally used in experimental medicine as a biological model. These animals are characterized by autoimmune hemolytic anemia developing with age and by the lups-like nephritis [8].
Nitric Oxide | 2005
Anatoly B. Shekhter; Vladimir A. Serezhenkov; Tatiana Rudenko; Alexander V. Pekshev; Anatoly F. Vanin
Biochimie | 2004
Sergey Shleev; O. V. Morozova; Oxana Nikitina; E.S. Gorshina; T.V. Rusinova; Vladimir A. Serezhenkov; Dosymzhan Sh. Burbaev; Irina G. Gazaryan; A. I. Yaropolov
Nitric Oxide | 2007
Anatoly F. Vanin; Natalia A. Sanina; Vladimir A. Serezhenkov; Dosymzhan Sh. Burbaev; Vladimir I. Lozinsky; S. M. Aldoshin
Nitric Oxide | 2008
K. B. Shumaev; Andrey A. Gubkin; Vladimir A. Serezhenkov; Irina I. Lobysheva; Olga V. Kosmachevskaya; Ruuge Ek; V. Z. Lankin; A. F. Topunov; Anatoly F. Vanin