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L I Valuev

Publications and source records attributed to L I Valuev.

29 records · Page 2Linked to original sources
PubMedDate not supplied

[Structure and functional properties of temperature-sensitive derivatives of immobilized proteins].

Polydiethylacrylamides (degree of polymerization, 13-470) containing a terminal carboxyl group were obtained by the method of radical polymerization of N,N-diethylacrylamide in the presence of mercaptoacetic acid. In the presence of 1-ethyl-(3,3-dimethylaminopropyl)-carbodiimide, these polymers reacted with ovomucoid to produce its polymeric derivatives. The values of the lower critical mixing temperature of these derivatives and the inhibitory activities of immobilized ovomucoid were determined by the length and amount of polydiethylacrylamide macromolecules bound to the molecule of ovomucoid.

Acrylamides↗
PubMedDate not supplied

[Oxidase activity of horseradish peroxidase in oxidation of the bilirubin-albumin complex].

The catalytic activity of horseradish peroxidase was investigated upon oxidation of the bilirubin-albumin complex (10(-5)-10(-4) M; BR: SA = 1: 1.5 mol/mol) by dissolved oxygen to biliverdin and other components. The process can be described by the Michaelis-Menten equation with Km = 14.4 microM and Vmax = 0.12 microM/min, if HRP = 3.1 x 10(-8) M. Oxidation is supposed to proceed in the triple complex--peroxidase: albumin: bilirubin.

Animals↗
PubMedDate not supplied

[Biospecific sorbent for removal of proteinases from biological fluids].

Sorbents for removal of proteases from biological fluids were synthesized via immobilization of a specific protease inhibitor-ovomucoid from whites of duck eggs--in the bulk of polymeric hydrogel. The sorbents were shown to exhibit high capacity and selectivity in the removal of proteases from the model protein-containing solutions, blood plasma and blood. The sorbents did not affect the blood cells as well as the blood-clotting system. The sorbents were demonstrated to be effective in the removal of proteases from canine blood in acute pancreatitis.

Acute Disease↗
PubMedDate not supplied

[Analysis of lytic effect on fibrin of immobilized heparin in complex with plasma proteins].

Reactions of heparin, covalently immobilized in hydrogel, with fibrinolysin, blood serum albumin, thrombin and fibrinogen were studied. All the proteins studied were shown to penetrate into the hydrogel pores and to interact with the immobilized heparin. Stability of the complexes was decreased in the following sequence: fibrinogen = thrombin much greater than fibrinolysin much greater than blood serum albumin. Complexes of the immobilized heparin with fibrinogen, thrombin and fibrinolysin hydrolyzed the unstabilized fibrin.

Adsorption↗
PubMedDate not supplied

[Covalent immobilization of the pancreatic trypsin inhibitor on a polymeric carrier].

Covalent immobilization of the pancreatic trypsin inhibitor onto a polymeric carrier was accomplished by introducing a double C = C bond in the inhibitor with a subsequent copolymerization of the activized inhibitor with acrylamide and N,N'-methylenebisacrylamide. To prevent a loss of the antitryptic activity under acylation of lysine residues of the reactive centre, the inhibitor was preliminary bound to a complex with trypsin, which was destructed by acidifying the solution before copolymerization. The antitryptic activity of the immobilized inhibitor was shown to be equal to the activity of the inhibitor in the native state.

Acrylamide↗
PubMedDate not supplied

[Problems in creating insulin preparations with increased stability against proteolysis].

Chemical methods that accelerate the transport of insulin and other polypeptides across biological membranes and increase their resistance to enzymatic hydrolysis are reviewed. These methods include chemical modification of insulin macromolecules, the use of compounds that increase the permeability of biological membranes or inhibit enzymatic proteolysis, the hormone immobilization in a polymer coat protecting it against the aggressive environment, the incorporation of insulin into liposomes, etc. The advantages and drawbacks of these methods are analyzed, and promising lines of research in this field of applied biochemistry are described.

Amino Acid Sequence↗
PubMedDate not supplied

[Preparation and characteristics of immobilized collagenase isolated from crab Paralithodes camtschatica].

Collagenolytic protease from hepatopancreas of king crab was immobilized on water-soluble reactive polymers containing N-succinimide units and possessing different hydrophobicity-hydrophilicity balance. The immobilized enzyme displayed higher heat stability, but its proteolytic activity decreased with the increase in the number of the copolymer hydrophobic groups. Highly active thermostable preparations of collagenolytic protease were obtained by copolymerization. The copolymerization did not affect the enzyme activity and increased the protease heat stability to the formation of pseudocross-links of protein molecules in their associates.

Animals↗
PubMedDate not supplied

[Interaction between globular proteins and water-soluble carbodiimides].

Interactions of a number of globular proteins with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide were studied. Under conditions of carbodiimide excess at a protein concentration lower than 88.5 x 10(-5) mol/l, the crosslinking reaction was found to proceed exclusively by an intramolecular mechanism. This resulted in conformational changes in the protein secondary structure and decreased its biological activity. At higher protein concentrations, the reaction of intramolecular crosslinking was always the first to proceed, and only then intramolecularly crosslinked proteins interacted. The reaction of intermolecular crosslinking was not followed by a further change in the protein conformation and activity.

Carbodiimides↗
PubMedDate not supplied

[Covalent binding of acylated trypsin with polymeric carriers].

In order to provide covalent binding of trypsin with polymer carriers, trypsin was activated by an administration of double C=C bond. Thereafter, activated trypsin was polymerized together with a monomer of the acrylic series. Trypsin acylation with an unsaturated acid allowed the enzyme immobilization by means of its copolymerization with a monomer forming a polymer matrix. The specific proteolytic activity of immobilized trypsin decreased in proportion to an increase in the molecular weight of the polymerization product.

Acylation↗