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1.
Kotel'nikov A. I. Ortega J. M. Medvedev E. S. Psikha B. L. Garcia D. Mathis P. 《Russian Journal of Electrochemistry》2002,38(1):77-87
The electron transfer from the heme of cytochrome c to the bacteriochlorophill dimer in reaction centers of photosynthetic purple bacteria Rps. sulfoviridis is studied by laser flash photolysis at 40–296 K in conditions where one, two, or three cytochrome hemes are chemically reduced. In the model used for the electron transfer kinetics, the protein relaxation is described with a temperature-independent oscillatory coordinate and a temperature-dependent diffusion coordinate, with the protein dielectric relaxation times widely distributed along the diffusion coordinate. It is found that all the protein complexes can be divided into proteins with fast (k
et = 107 to 10–4 s–1) and slow (k
et 100 s–1) electron transfer. These populations presumably differ by the protonation state of the functional group. The contribution of the oscillatory and diffusion coordinates alters, which severely affects k
et. Parameters V
ab, G, , 0, and for these reactions are determined. 相似文献
2.
L. A. Syrtsova A. I. Kotel’nikov B. L. Psikha E. S. Malkova N. I. Shkondina E. I. Gainullina 《Russian Chemical Bulletin》2007,56(4):754-760
Hemoglobin (Hb) reduces 3,3-bis(nitroxymethyl)oxetane (NMO) only in the presence of cysteine (Cys) via intermediate cysteine thionitrate. The kinetics of the reaction of NMO with Cys and the kinetics and mechanism of formation
of NO in the ternary system Hb-NMO-Cys were studied. The formation rate of Hb-NO in the ternary system is higher than that
of Hb-NO in the reaction of Hb only with NO
2
−
generated in the binary system NMO-Cys. The second-order rate constants of the main reaction steps in the system Hb-NMO-Cys
were estimated by simulating the kinetics of the reactions with a system of equations taking into account equilibria between
all components of the reaction mixture. Hemoglobin reduces cysteine thionitrate, the intermediate in the reaction of NMO with
Cys, to NO.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 725–731, April, 2007. 相似文献
3.
Neshev N. I. Sokolova E. M. Psikha B. L. Rudneva T. N. Sanina N. A. 《Russian Chemical Bulletin》2016,65(3):779-783
Russian Chemical Bulletin - The kinetic regularities of nitric oxide donation in the presence of erythrocytes by representatives of a new class of synthetic nitric oxide donors, binuclear... 相似文献
4.
N. I. Neshev B. L. Psikha E. M. Sokolova N. A. Sanina T. N. Rudneva S. V. Blokhina 《Russian Chemical Bulletin》2010,59(12):2215-2218
The kinetics of erythrocyte hemolysis and intra-erythrocyte hemoglobin oxidation under the action of synthetic sulfur-nitrosyl
iron complexes was studied. The complexes capable of releasing nitric oxide due to spontaneous hydrolytic decomposition was
studied. The addition of these complexes to a 0.2% suspension of mouse erythrocytes results in hemolysis. The kinetic curves
of hemolysis exhibit an induction period, whose duration is different for each complex. The hemolysis is preceded by hemoglobin
oxidation with nitric oxide penetrating into the cell. The oxidation of hemoglobin follows the first-order rate equation.
The apparent first-order rate constants characterizing the NO-donating ability of each complex were determined. The hemolytic
effect of the studied complexes is suggested to be related to the formation of peroxynitrite inside erythrocytes. Peroxynitrite
is the cytotoxic product of interaction of nitric oxide and the superoxide radical anion. 相似文献
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6.
Sanina N. A. Syrtsova L. A. Psikha B. L. Shkondina N. I. Rudneva T. N. Kotel’nikov A. I. Aldoshin S. M. 《Russian Chemical Bulletin》2010,59(10):1994-1998
By an example of the iron cysteamine nitrosyl complex {Fe2[S(CH2)2NH3]2(NO)4}SO4··2.5H2O (CAC), it was shown for the first time that the hydrolysis of this NO donor in the presence of ferrocytochrome c (cyt c
2+) affords the iron nitrosyl complex NO-cyt c
2+, which serves as the NO depot. The rate constant of NO release from CAC was determined from the kinetics of the formation
of NO-cyt c
2+. At pH 3.0 the rate constant is (2.7±0.1)·10−3 s−1. Ferrocytochrome c produces a less stabilizing effect on CAC than deoxyhemoglobin (Hb). Thus in the presence of cyt c
2+, the reaction is completed in 1 h, whereas NO is released from a solution of CAC (2·10−4 mol L−1) in the presence of Hb during 40 h. The previously unknown stabilization of iron nitrosyl complexes by hemoglobin was found. 相似文献
7.
Kotelnikov AI Ortega JM Medvedev ES Psikha BL Garcia D Mathis P 《Bioelectrochemistry (Amsterdam, Netherlands)》2002,56(1-2):3-8
The broad set of nonexponential electron transfer (ET) kinetics in reaction centers (RC) from Rhodopseudomonas sulfoviridis in temperature range 297-40 K are described within a mixed adiabatic/nonadiabatic model. The key point of the model is the combination of Sumi-Marcus and Rips-Jortner approaches which can be represented by the separate contributions of temperature-independent vibrational (v) and temperature-dependent diffusive (d) coordinates to the preexponential factor, to the free energy of reaction DeltaG=DeltaG(v)+DeltaG(d)(T) and to the reorganization energy lambda=lambda(v)+lambda(d)(T). The broad distribution of protein dielectric relaxation times along the diffusive coordinate is considered within the Davidson-Cole formalism. 相似文献
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The reaction of the nitric oxide donor, viz., iron tetranitrosyl complex bearing the thiosulfate ligand (TNIC), with adenosine triphosphoric acid (ATP) was studied.
By spectrofluorometry and electronic microscopy, the formation of the reaction products of ATP both with TNIC and with Na2S2O3 and FeSO4 was shown and the complexation constants of ATP with these compounds were calculated. 相似文献