Biomedical subjects
Publications and source records attributed to V K Latov.
Thirty patients with peritonitis of different etiology were examined. Deep alterations of protein metabolism were revealed resulting from dyscoordination of amino acid metabolism. Efficiency of unbalanced amino acid mixtures was shown and on the contrary, the absence of a therapeutic effect when using balanced mixtures.
This report presents experimental data on kinetics of casein hydrolysate hydrolysis. The experiments were interpreted in the framework of a theory reported, which is guided by an experimentally measurable value--a total molar concentration of all peptides and amino acids (total amino nitrogen). The total amino nitrogen N was determined by photometry of N-trinitrophenyl (N-TNP) derivatives obtained by means of trinitrobenzenesulfonic acid (TNBS). Unlike the procedures reported previously, we stopped the proteolysis reaction by boiling, and performed the trinitrophenylation in a 20% V. aqueous solution of MeCN.
Experiments were carried out to study the effect of the styrene and maleinic acid copolymer on the activity of proteases produced by Bacillus subtilis--protosubtilin G15x. Unlike the hydrophilic ethylene--maleinic acid copolymer, styrenated maleinic acid produced a stabilizing effect on proteases via hydrophobic interaction. It is suggested that at least two forms of the enzyme differing in their activity and stability are involved in the process of inactivation. On the basis of the data obtained a scheme of protease inactivation is proposed.
The kinetics of the initial stages of autolysis of the yeast Saccharomyces cerevisiae was studied and the following kinetic parameters were determined: induction period, steady-state rate of the enzyme-induced effect, and steady-state concentration of intermediate products. It was shown that appropriate inducers were able to cause a more than fourfold increase in the rate of reactions catalyzed by proteinases and almost a tenfold increase in the concentration of intermediate peptides. The mean length of the peptide molecules formed in the process was determined and dependence of this value on the degree of hydrolysis was demonstrated.
Yeast autolysis and hydrolysate composition were studied with respect to the autolysis of baker's pressed yeast. A method of isolating a mixture of amino acids and lower peptides from autolysates was developed, using ion-exchange resins. The above compounds reached maximum accumulation by the 15-20th hour of autolysis. A mixture of amino acids applicable to nutrition, including dietotherapy, was prepared.
The possibility of coordination immobilization of fungal enzymes from Aspergillus niger MB and Aspergillus flavipes on the styrene copolymer with maleic acid has been explored. Optimal conditions for preparing insoluble chromium-containing enzyme polymeric complexes have been studied. The synergistic effect of salts of different metals on stability of chromium-containing immobilized preparations has been demonstrated. Properties of the resultant immobilized preparations have been examined.
In the presence of food fibers, proteolysis occurs with the formation of sorption complexes. At the initial stages of hydrolysis, the adsorption of both casein and pepsin is observed, the adsorption influencing the initial rate of hydrolysis. The composition of the sorption layer changes during hydrolysis in favor of intermediates. The initial and stationary rates of hydrolysis depend on the protein/fiber ratio. The catalytic activity of the system decreases both with a little amount and with an excess of fibers. The highest rate of hydrolysis is observed at a protein/fiber ratio of 1/2.
Insoluble enzymes have been obtained through an interaction of the complex preparation of proteases, protosubtilin G15x, with the sterol and maleic anhydride copolymer in aprotic dipolar solvents and as a result of formation of mixed enzyme-polymer complexes of protosubtilin G15x and the sterol and malic acid copolymer in aqueous solution in the presence of metal ions. The effect of metal ions on the yield and activity of the resultant immobilized preparation has been studied.