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R M Davydov

Publications and source records attributed to R M Davydov.

At least 19 recordsLinked to original sources
PubMed1986

[Effect of lipids and substrates on the kinetics of binding of ferrocytochrome P-450 to CO].

Using the flash photolysis technique, it was found that the kinetics of recombination of carbon monoxide with ferrocytochrome P-450 LM-2 can be approximated by the sum of three exponents. Incorporation of cytochrome P-450 into liposomes prepared from microsomal lipids leads to the reduction of the number of steps to two as well as to essential changes in rate constants. Addition of type I substrates (Triton N-101, albumin) cause similar changes in the reaction kinetics. NADPH-cytochrome P-450 reductase has no effect on this process. The multistep kinetics of CO recombination with cytochrome P-450 LM-2 may be accounted for by the presence of some protein conformers. The experimental results suggest that the activity and structure of cytochrome P-450 conformers is affected by the lipid microenvironment, type I substrates and Triton N-101.

Animals↗
PubMed1979

Spectral properties of nonequilibrium states in cytochrome P-450 formed by reduction at subzero temperatures.

Nonequilibrium conformational states in cytochrome P-450 in the presence and absence of substrates formed by reduction at subzero temperatures with hydrates electrons were obtained and characterized by their absorption spectra. Different absorption spectra between the relaxed (298 K) and the non-relaxed enzyme forms (77 K) indicate conformational changes proceeding in the relaxed form after reduction of the heme iron which lead to altered interactions between the active centre and its environment in the protein. The two maxima of the nonequilibrium form of cytochrome P-450 without substrate in the visible absorption spectrum (alpha-band, beta-band) and the ratio of their intensities indicate the low-spin character of the heme iron. These spectral properties give evidence for a reduced cytochrome P-450 with two heme-linked axial ligands.

Animals↗
PubMed1975

Studies on the conformational changes of metalloproteins induced by electrons in water-ethylene glycol solutions at low temperatures. III. Adrenal ferredoxin.

The reduction of adrenal ferredoxin (adrenodoxin) at low temperatures was investigated in order to separate local modifications of the active centre of the protein on its reduction, from the conformational transition which seems to accompany the change of the redox state of the irons; The ESR spectra of the states of the protein, where the reduced active centre is to be found by the "oxidized" conformation of the apoprotein, were obtained. The transition from the states of the protein to the state which occurs on its chemical reduction at room temperature was also investigated. The results of the work support the view that conformational changes in proteins (enzymes) which take place while they are functioning proceed after modifications of the active centres (change of the redox state, adsorption of a substrate, etc.), and are essentially caused by them. Adrenal ferredoxin was the third subject in our studies of the intermediate states of proteins which appear after reduction of their active centres by means of electrons trapped in water-ethylene glycol mixtures at the temperature of liquid nitrogen [1, 2]. In the reduced state, the active centre of the protein has an ESR signal with a g-factor of 1.94 [3, 4] which is convenient for our purposes.

Adrenodoxin↗