[A granulopoiesis inhibitor. Synthesis and biological activity].

Three schemes of synthesis for pentapeptide Glp-Glu-Asp-Cys-Lys-OH were compared was carried out. Acetamidomethyl protection was used for the mercapto group of cysteine. For the same purpose, cystine was used as the starting compound for synthesis.

[Immunoenzyme method of determining trace amounts of proinsulin in recombinant human insulin].

An enzyme immunoassay (ELISA) for the detection of human proinsulin has been developed based on the interaction of the absorbed proinsulin with the antiserum against the synthetic proinsulin C-peptide. In the presence of high concentrations of insulin, the sensitivity of the assay slightly decreases due to the competitive adsorption of insulin onto the polystyrene carrier with the binding constant 800-1000 times less than that of proinsulin. A method is proposed for the interpretation of ELISA data based on analysis of a weighed dry insulin sample, which enables the detection of a 0.

[Use of arylsulfenylchlorides for cleaving fibrinogen at methionine residues].

Conditions for the fibrinogen fragmentation with 2-pyridyl-or o-nitrophenylsulfenylchloride were proposed. Resulting mixture of fragments is identical to the mixture prepared by the cyanogen bromide treatment and is suitable as supplementary analytical reagent in the determination of the tissue plasminogen activator (TPA) activity with a chromogenic substrate.

[The heterogeneous character of protein modification during substitution of their amino groups. Acylation of alpha-chymotrypsin].

Thin-layer isoelectric focusing of chymotrypsin modified by stepwise acylation with acryloyl chloride or maleic anhydride revealed a high heterogeneity of modification products, with a maximal number of components near 50% of substituted amino groups. Disc electrophoresis failed to establish the products diversity and could not therefore be used for heterogeneity control. The activity of the modified enzyme towards proteins and low molecular weight substrates depended on the modification reagent and correlated with the electrostatic enzyme--substrate interaction.

[Preparation of subtilisin BPN' and dextran conjugates].

The conditions for subtilishine BPN' binding with bromocyanogen activated dextranes have been selected. The dependence of the enzyme activity and stability from pH and temperature levels has been studied. The stability of a modified enzyme during storage in solution is increased as compared with that of the native enzyme due to a decrease in the autolysis rate.

[Effect of peptide hormones of the gastrointestinal tract on leukocytes].

A single i. m. administration of pentagastrin or secretin changed the amount of lymphoid and myeloid cells in rats and mice.

[Role of the molecular environment in chlorophyllase functioning during its immobilization on organic carriers].

Immobilization of chlorophyllase was performed on aminohexadecyl sepharose, aminoundecyl sepharose and heptyl sepharose. The enzyme activity lowers considerably and is rather close for all carriers. Essential differences are manifested in stability of the preparation during storage.

Interaction of synthetic human big gastrin with blood proteins of man and animals.

Radio gel and affin chromatography were used to study big gastrin interaction with blood proteins of man and animals. The experiments showed that big gastrin interacts with serum proteins in vitro. The gastrin-blood protein complex is labile and readily dissociates (T 1/2 = 8--14 min).

[Reaction between prolactin and serum proteins. II. Prolactin-binding gamma globulin of normal animal serum].

The authors identified prolactin-binding proteins in the blood of goats and rats. Proteins were isolated by affine chromatography. It was shown by gel filtration on Sephadex G-200 and Sepharose-6B and also by disc electrophoresis in polyacrylamide gel and zonal electrophoresis in agarose that these proteins were referred to gamma-globulins.

Relation between structure and function in some partially synthetic ribonucleases S'. Enzymic and spectroscopic investigation on [Orn10, Asn14]-RNase S' and 1epsilon, 7epsilon, 10delta-triguanidino-[Orn10, Asn14]-RNase S'.

Some analogues have been prepared of S-peptide, the peptide obtained together with S-protein from subtilisn-modified beef pancreatic R Nase A. The syntheses are described of [Orn10, Asn14]-S-peptide and 1epsilon, 7epsilon, 10delta-triguanidino-[Orn10, Asn14]-S-peptide. The S-peptide analogues are able to activate S-protein at the level of the parent [Orn10]-S-peptide and 1epsilon, 7epsilon-diguanidino-S-peptide respectively, although at high peptide-to-protein molar ratios.