[Synthesis of ATP and free radicals in an aqueous solution, containing NADH, riboflavin, ADP and inorganic phosphate]. / Sintez ATF i svobodnye radikaly v vodnom rastvore, soderzhashchem NAD.N, riboflavin, ADF i neorganicheskii fosfat.

pH-dependence of initial (admixture) adenosine triphosphate (ATP) changes (ATP synthesis and hydrolysis) was studied for aerated and deaerated aqueous solutions during the incubation of adenosine diphosphate (ADP) and inorganic phosphate (Pi) in the presence of reduced nicotinamide adenine dinucleotide (NADH) and riboflavin (Rf). The preferential pH regions were indicated both for ATP synthesis and ATP hydrolysis (pH less than pH 5.4, 5.9 divided by pH 6.5 and pH greater than 6.6, pH 5.5 divided by pH 5.8 respectively). 'Free radical content measurements were paralleled by ESR technique. On the basis of the obtained results it was assumed that a part of ESP signal attributed to ADP radicals was increased during ATP synthesis.

[Segmental flexibility of Fc-region of spin labeled 2 subclasses of IgG molecule from cow blood and local conformational mobility of their carbohydrate components]. / Segmental'naia gibkost' Fc-oblasti spin-mechenykh molekul IgG dvukh podklassov syvorotki krovi korov i lokal'naia konformatsionnaia podvizhnost' ikh uglevodnykh komponent.

Spin-label was bound to carbohydrates of Fc-region of two subclasses of the IgG molecule from the blood serum of healthy and ill cows. By the value of rotational correlation time (10 nsec) internal flexibility of Fc-region of both IgG subclasses and by value of the order parameter (S = 0.9)--rigid attachment of oligosaccharide chains to protein parts of the molecules were found. At the same time the states of IgG1 an IgG2 molecules determined by dynamic steric characteristics for ill and healthy cows did not differ.

[Measurements of the time of rotational correlation of bovine serum albumin molecule using iodine and mercury-containing spin-labels]. / Izmerenie vremeni vrashchatel'noi korreliatsii molekuly bych'ego syvorotochnogo al'bumina s pomoshch'iu iod- i rtut'soderzhashchikh spin-metok.

New spin-labels based on iodine and hydrargirum containing imidazolids were approbated on the bovine serum albumin (BSA) molecule. It is shown that all hydrargirum labels are binded to the external SH-group of BSA practically immediately in comparison with earlier known spin-labels based on piperidine with maleimide and iodacetamide groups, requiring some minutes of hours, correspondingly. Rotational correlation times and the character of relative mobility of the spin-label were measured. Values of the rotational correlation times of the protein molecule obtained by hydrargirum containing labels were found in the range of correlation times typical for the BSA molecule and represent at pH 7.0 a rigid stretch ellipsoid of rotation. The result obtained revealed that the relative reorientation nature of spin-labels is essentially different and is taken into account in different values of order parametres S according to model--fast anisotropic rotator on slow isotropic rotator. ESR spectra based on theoretical calculations by means of computer are given.

Selective spin-labelling of an N-acetylneuraminic acid residue in the Fab-region oligosaccharide of immunoglobulin M.

A method is proposed for spin-labelling using 2,2,6,6-tetramethyl-4-aminopiperidine-1-oxyl, the N-acetylneuraminic acid residue within the Fab-region oligosaccharide of immunoglobulin M (IgM). The selectivity of spin-labelling was achieved by the controlled periodate oxidation of the oligosaccharide groups of the IgM prior to the spin-labelling. The spin-labelled IgM prepared in this way may be useful for the studies of dynamics of the IgM structure, particularly upon antigen binding.

[Energizing of F1-ATPase after irradiation with visible light]. / Energizatsiia F1-ATFazy pri obluchenii vidimym svetom.

It was shown that ATP synthesis by F1-ATPase sensitized by visible light was combined with oxidation of SH groups and decrease of initial flavin fluorescence in the F1-ATPase preparation. It was suggested that it was an endogenous flavin group that regulated redox transitions between SH-S-S groups which was essential for the catalysis in vivo.

[Changes in the segmental flexibility and conformation stability of side groups in spin-labeled molecules of 2 IgG subclasses in the serum of normal cows and cows in various pathological states]. / Razlichiia v segmental'noi gibkosti i lokal'noi konformatsionnoi podvizhnosti bokovykh grupp spin-mechenykh molekul dvukh podklassov IgG syvorotki krovi korov v norme i pri patologii.

The segmental flexibility of molecules from two IgG subclasses of cows' blood serum was first observed. It was shown that IgG1 molecule has a more flexible hinge region than IgG2 molecule and lower local conformational stability. At the same time the states of IgG1 and IgG2 molecules determined by dynamic-steric characteristics for ill and healthy cows practically did not differ.

[Determining the motility of glycoprotein oligosaccharides from lymphocyte membranes using the spin label method]. / Opredelenie podvizhnosti oligosakharidov glikoproteinov iz membran limfotsitov metodom spinovoi metki.

Splenocyte glycoproteins solubilized by papain were purified on lectyl-lectin Sepharose 4B. Glycoproteins eluted from lectin were spin-labeled at carbohydrates. Quantitative evaluation of ESR spectra of spin-labeled glycoproteins pointed to strong restriction of reorientation of the spin label bound to oligosaccharides. Calculated correlation time of relaxing volume tagged with the spin label was equal to the molecular weight about 6000-7000 dalton. This value suggests the existence of flexibility of the glycoproteins studied.

[Segmental motility of the COOH-terminal fragment of immunoglobulin G heavy peptide chains in a solution]. / Segmental'naia podvizhnost' COOH-kontsevogo fragmenta tiazhelykh peptidnykh tsepei immunoglobulina G v rastvore.

The rotational correlation time of pFc' fragment of IgG1 determined by spin-label method was found to be equal to 5.2 nsec. This value points to the significant segmental mobility of Ch3 domains built fragment as well as to the structural lability of Ch3 domains themselves.