Biomedical subjects

E K Deniakina

Publications and source records attributed to E K Deniakina.

6 recordsLinked to original sources

PubMedDate not supplied

[Hydrolysis of peptides by immobilized bacterial peptide hydrolases].

The feasibility of hydrolysis of a mixture of peptides with an enzyme from the bacterium Xanthomonas rubrilineans, displaying a peptidase activity and immobilized on aluminum oxide, was studied. Kinetic schemes and equations allowing for approaching quantitative description of peptide hydrolysis in complex mixtures containing free amino acids and peptides were obtained. It was demonstrated that as a result of hydrolysis, the content of free amino acids in hydrolysates decreased 2.5- to 3-fold and the molecular weight of the constituent peptides, 2-fold.

Aluminum Oxide↗

PubMedDate not supplied

[Enzyme preparations for research on protein hydrolysates and amino acid mixtures not containing peptides].

Some properties and the hydrolysing ability of two novel enzyme preparations, a proteolytic preparation "C" from Acremonium chrysogenum (Cephalosporium acremonium) and a peptidase preparation (the producer from the family Pseudomanadaceae), are described. The preparations can be used for obtaining protein hydrolysates with different ratios of free amino acids and peptides. The protein hydrolysis with the preparation "C" enables one to obtain hydrolysates containing 13-18% of free amino acids. The further treatment of the hydrolysates with the peptidase preparation results either in complete hydrolysis of the remained peptide fractions or in obtainment of solutions containing from 60 to 85% of free amino acids and low-molecular weight peptides.

Amino Acids↗

PubMedDate not supplied

[Production and properties of an immobilized enzyme preparation with peptidase activity].

A heterogeneous multienzyme preparation with the peptidase activity, isolated from the cells of Pseudomonadacea bacteria, was immobilized on alumina. The specific activity of the immobilized enzyme complex is not a simple function of the bound protein quantity, but depends on immobilization conditions. An additional glutaraldehyde treatment results in higher thermostability of the immobilized enzyme preparation. The substrate specificity of the preparation retains after immobilization, and it becomes less sensitive to pH changes.

Aluminum Oxide↗

PubMedDate not supplied

[Amino acid and peptide ratio in protein hydrolysates for parenteral feeding].

Using the method of amino acid analysis and routine methods of protein biochemistry, the ratio of amino acids and peptides in acid and enzyme protein hydrolyzates was determined. Depending on the production procedure, the hydrolyzates under study contained various amounts of free amino acids and peptides in which the number of amino acid residues varied from 2 to 7. Additional hydrolysis of these preparations by leucine aminopeptidase led to a decrease in the peptide content and to an increase in the amino acid content. This may have a beneficial effect on the quality of protein hydrolyzates.

Amino Acids↗

PubMedDate not supplied

[Conditions for immobilizing protosubtilin on aluminum oxide using transitional metal ions].

The effect of the degree of the carrier activation by titanium tetrachloride, type of buffer solution, and protein concentration on characteristics of protosubtiline G10x immobilized on alumina was studied. X-ray phase analysis and IR spectroscopy were used to investigate the structure of the carrier and its changes during activation. To obtain the immobilized enzyme preparation with the maximum activity, immobilization should be carried out in 0.02 M Ca-acetate buffer on alumina treated with 2% solution of titanium tetrachloride.

Aluminum↗

PubMedDate not supplied

[Casein hydrolysis by immobilized protosubtilin].

A study was made of the kinetics of sodium caseinate hydrolysis by protosubtilin G10X (Bac. subtilis producer) immobilized on silica gel with the aid of glutar dialdehyde. Optimal conditions for making the process were selected (pH 8.5, temperature 60 degree C, substrate concentration 0.3%). The apparent kinetic parameters of the reaction were calculated. An empiric equation that can be used for practical calculation was derived from the Michaelis-Menten equation with the use of the values obtained (Km = 2.48 +/- 0.10 micrometer/ml, Vmax = 25.6 +/- 1.9 micrometer/min/mg conventional protein).

Bacillus subtilis↗