[Disordered regions in C-domain structure of influenza virus M1 protein].

Influenza virus matrix M1 protein is one of the main structural components of the virion performing also many different functions in infected cell. X-ray analysis data with 2.08 angstrom resolution were obtained only for the N-terminal part of M1 protein molecule (residues 2-158) but not for its C-terminal domain (159-252). In the present work M1 protein of A/Puerto Rico/8/34 (H1N1) virus strain in acidic solution was investigated with the help of tritium bombardment. Tritium label incorporation into M1 protein domains preferentially labeled the C-domain and inter-domain loops. Analytical centrifugation and dynamic light scattering experiments demonstrated increased hydrodynamic parameters (diameter) that may be explained by low degree of M1 structural organization. Computational analysis of M1 protein by intrinsic disorder predictions methods also demonstrated the presence of unfolded regions mostly in the C-domain and inter-domain loops. It is suggested, that influenza virus M1 polyfunctionality in infected cell is determined by its tertiary structure plasticity which in its turn results from the presence of unstructured regions.

[Comparative study of structural stabylity of potato virus X coat protein molecules in solution and in the virus particles].

With help of several optical methods and differential scanning calorimetry we studied the structure and stability of molecules of coat protein (CP) of filamentous of potato virus X (PVX) in free state and in the virions. According to the results of all these methods, at room temperature (25 degrees C) free PVX CP subunits possess some fixed tertiary structure but this structure is highly unstable and is completely disrupted at temperatures as low as 35 degrees C. The free PVX CP tertiary structure was also disrupted by very low sodium dodecylsulfate and cetyltrimetylammonium bromide concentrations: 3 to 5 moleculs of the surfactants per the CP molecule were sufficient to induce its total disruption. At the same time, these treatments did not result in any changes in the PVX CP secondary structure. Incorporation of the CP subunits into the PVX virions resulted in a strong increase in their stability to effects of increased temperatures and surfactants. This combination of highly labile tertiary structure and rather stable secondary structure of free PVX CP subunits may represent a structural basis for recently observed capacity of the PVX CP moleculs to assume two different functional states in the virion.

[Heme-heme interactions in circular dichroism spectra]. / Proiavlenie gem-gem vzaimodeistviia v spektrakh krugovogo dikhroizma.

Using the theory of optical activity by Kirkwood and Tinoco, the CD spectra of the heme peptides in mono- and dimeric forms have been calculated according to the simple spectral model of heme of Simpson.

[Study of the complex of myoglobin with nicotinic acid by the method magnetic circular dichroism. Nature of the double hemochromogen]. / Issledovanie kompleksa mioglobina s nikotinovoi kislotoi metodom magnitnogo krugovogo dikhroizma. K voprosu o prirode dvoinogo gemokhromogena.

The complex formed by myoglobin and nicotinic acid exhibits unusual spectral properties. Instead of the usual two bands in the visible region the complex shows four bands assigned to the so called twin hemochromogen. Some attempts were previously made to clarify the nature of the twin hemochromogen, but the interpretation given was somewhat doubtful. We have shown that the combination of two spectral methods, namely magnetic circular dichroism and absorption spectra, give evidence that unusual absorption spectrum of the myoglobin complex with nicotinic acid is not attributed neither to the presence of the other hemochromogen nor to the soft vibrations but is due to the strong splitting of the pure electronic Q00 band into two Qox and Q0y bands. The splitting is caused by the distortion of heme structure by its asymmetrical environment.

[Absorption spectrum and magnetic circular dichroism of heme-containing proteins in nonequilibrium states. I. Hemoglobin and its derivatives]. / Spektry pogloshcheniia i magnitnogo krugovogo dikhroizma gemosoderzhashchikh belkov v neravnovesnykh sostoianiiakh. I. Gemoglobin i ego proizvodnye.

Absorption and magnetic circular dichroism spectra of nonequilibrium states of hemoglobin and its derivatives formed by reduction oxidased forms of hemoproteins by thermalysed electrons at 77 degrees K were studied. Mixtures of low spin and high spin ferroforms were observed for nonequilibrium hemoglobin and its complexes with inosithexaphosphate and fluorine. The content of the high spin form increasing as follows: hemoglobin, complex with inosithexaphosphate, complex with fluorine. Only low spin forms were found for cyanide and azide complexes of hemoglobin reduced at low temperature. The spectral differences of nonequilibrium low spin ferroforms were supposed to be due to the presence of different ligands in the coordination sphere of the heme iron. The alpha-band splitting was observed for the nonequilibrium imidazole complex of hemoglobin. This effect was explained by a lowe-ring of the active centre's symmetry. The temperature relaxation of all nonequilibrium systems was investigated.

[Absorption and magnetic circular dichroism spectra of heme proteins in nonequilibrium states. IV. Cytochrome c and its derivatives]. / Spektry pogloshcheniia i magnitonogo krugovogo dikhroizma gemsoderzhashchikh blekov v neravnovesnykh sostoianiiakh. IV. Tsitokhrom s i ego proizvodnye.

Absorption and magnetic circular dichroism spectra (77 degrees K) of nonequilibrium cytochrome c and its derivatives reduced by thermolysed electrons was studied. The low temperature spectral characteristics of reduced cytochrome c (pH 7.0, 1.6 and 10.0), dimer, carboxymetylated and formylated derivatives at netral and acid pH, also fluoride complexes differ from the characteristics of equilibrium reduced forms. The temperature increase (up to 177 degrees K) induces relaxation of nonequilibrium states. These effects are due to structural differences in the heme vicinity of the reduced and oxidized forms.

[Absorption and magnetic circular dichroism spectra of nonequilibrium states of hemoproteins. II. Myoglobin and its complexes]. / Spektry pogloshcheniia n magnitonogo krugovogo dikhroizma gemsoderzhashchikh blekov v neravnovesnykh sostoianiiakh. II. Mioglobin i ego kompleksy.

Absorption and magnetic circular dichroism spectra of non-equilibrium states of myoglobin and its complexes formed by reduction oxidased forms of proteins by thermalysed electrons at 77 degrees K were studied. Mixtures of high spin and low spin ferroforms were observed for nonequilibrium states of myoglobin and its complex with fluorine, the content of the high spin form is larger in the complex. Two intense peaks were found in the alpha-band region of absorption spectra of myoglobin and its spectra with F-, OH- and imidazole. This effect is due to lowering of the active centre's symmetry. Similarity of spectral characteristics of low spin ferroforms of these complexes was explained by the strong influence of distal histidine. The low temperature reduction of azide and cyanide complexes of myoglobin led to formation of nonequilibrium low spin ferroforms whose spectra demonstrate the presence of N3- and CN- in heme iron's coordination sphere. The temperature relaxation of all nonequilibrium systems were investigated.

[Absorption and magnetic circular dichroism spectra of nonequilibrium states of hemoproteins. III. Complexes of peroxidase]. / Spektry pogloshcheniia i magnitnogo krurovogo dikhroizma gemsoderzhashchikh belkov v neravnovesnykh sostoianiiakh. III. Kompleksy peroksidazy.

Absorption and magnetic curcular dichroism spectra of nonequilibrium states of peroxidase and its complexes with F-, N3-, CN- produced by reduction of oxidased forms of proteins by thermalysed electrons at 77 degrees K were studied. Mixtures of high spin and low spin ferroforms were found in nonequilibrium states of peroxidase and complexes with F- and N3-, the content of the high spin ferroform increasing as follows: N3- complex less than peroxidase less than fluorine complex. Only low spin ferroforms was found after low temperature reduction of the cyanide complex. The existence of the low spin ferroform in equilibrium states of peroxidase and its complex with F- was explained by location of iron near the porphyrine plane. In the case of azide and cyanide complexes the existence of the low spin form is due to the presence of these ligands in heme iron's coordination sphere. The temperature relaxation of all nonequilibrium forms was investigated and a possible mechanism of the process is proposed.

[Recombinant human insulin. VII. Increased efficacy of chromatographic separation based on a principle of bifunctionality]. / Genno-inzhenernyi insulin cheloveka. VII. Povyshenie éffektivnosti khromatograficheskogo razdeleniia pri ispol'zovanii printsipa bifunktsional'nosti.

Retention mechanisms of insulin and deamido[AsnA21] insulin on the bifunctional sorbent Armsphere-C8(PR) in conditions of reversed-phase chromatography (HPLC and ion-pair HPLC) were studied. In accordance with the chemical differences of these proteins, molecular mechanisms of their interaction with silica gel modified with hydrophobic and ion-exchange groups were revealed. The possibility of simultaneous interaction of sorbed proteins with the stationary phase by both mechanisms under conditions of reversed-phase HPLC was demonstrated. The dependences of the separation selectivity and resolution on the mobile phase composition and properties (a salt buffer type, pH, ionic strength) were found. It was demonstrated that the separation selectivity can be regulated by altering the contribution of each of the two separation mechanisms and the bifunctional sorbent used allows higher selectivity in the separation of close protein analogs than monofunctional sorbents.

[Genetic engineering of human insulin. IV. Development and optimization of an analysis system using reversed phase high pressure liquid chromatography]. / Genno-inzhenernyi insulin cheloveka. IV. Razrabotka i optimizatsiia sistemy analiza s pomoshch'iu obrashchenno-fazovoi vysokoéffektivnoi zhidkostnoi khromatografii.

The effectiveness of the RP HPLC application for the step-by-step analysis of the recombinant insulin production was studied. Properties of a number of commercial and experimental columns in different chromatographic conditions were considered. A three-dimension optimization of selectivity and resolution versus pH and ion strength was carried out. A mechanism of the resolution and selectivity control is suggested.

[Genetically engineered human insulin. 1. HPLC in analyzing products of basic production stages]. / Genno-inzhenernyi insulin cheloveka. 1. VEZhKh v analize produktov osnovnykh stadii proizvodstva.

Application of some variants of HPLC for the step-by-step analysis of recombinant human insulin production was studied. Chromatographic columns with commercial and specially developed supports for size-exclusion, ion-exchange and reverse phase HPLC were used. Effective combinations of the chromatographic techniques for analysis of products and intermediates at every technological step were found and used for production of insulin. The authenticity of insulin obtained in the Shemyakin Institute of Bio-organic Chemistry by the scheme described in the present paper was confirmed by means of some physical and chemical methods and biological activity analysis.

[Secondary structure and amino acid composition of protein complex associated with the rod part of myosin molecule]. / Vtorichnaia struktura i aminokislotnyi sostav belkovogo kompleksa, sviazannogo so sterzhnevoi chast'iu molekuly miozina.

The secondary structure and amino acid composition of a protein complex (LMM-Rp) bound to the heavy chains (HC) of light meromyosin (LMM), and the secondary structures of LMM and its fractions obtained at an intermediate stage of LMM-Rp preparation were studied. The data obtained were compared with the similar ones for LMM HC and for the myosin light chains (LC). For the secondary structure study the data of CD-spectra were used. This structure was characterized by molar parts of the amino acid residues belonging to four different conformations: alpha-helices, beta-structures, beta-bends and irregular coils. In LMM-Rp unlike HC and LC, the alpha-helices are nearly absent, and appreciable parts of irregular coils and beta-bends are present. The amino acid compositions of LMM-Rp, HC and LC markedly differ. This difference is more significant when LMM-Rp is compared with HC, then with LC. This is an accordance with comparable data for the secondary structure.

[Conformation and reduction-oxidation properties of cytochrome c incorporated into reversed micelles of a surfactant in an organic solvent]. / Konformatsiia i okislitel'no-vosstanovitel'nye svoistva tsitokhroma c, vkliuchennogo v obrashchennye mitselly poverkhnostno-aktivnogo veshchestva v organicheskom rastvoritele.

Changes observed in CD- and absorption spectra of cytochrome c solubilized in reversed micelles AOT showed significant structural transformations of protein in the region of the active centre and particularly revealed a replacement of the sixth ligand of heme iron. These changes also affected the redox properties of cytochrome c.

[Antihypoxic activity of cytochrome c heme peptides]. / Antigpoksicheskaia aktivnost' gem-peptidov tsitokhroma c.

A comparative study of antihypoxic activity of five and two cytochrome c derivatives was performed during their single prophylactic administration on the model of acute hypobaric hypoxia (AHBH) and during rehabilitation period after AHBH, respectively. Antihypoxic efficiency of cytochrome c derivatives was shown to be dependent on doses, time of drug administration, and type of experimental animal resistance. The heme-nonapeptide of cytochrome c proved to be of maximum efficiency during prophylactic administration and rehabilitation period after AHBH.