[Calcitonin: properties and methods of production]. / Kal'tsitonin: svoistva i sposoby polucheniia.

Calcitonin structure, biological activity, formation in organism and methods of production including isolation from natural sources, chemical synthesis and genetic engineering methods are reviewed.

[Effect of peptides--structural analogs of NH2-terminal sites of fibrin alpha- and beta-chains--on specific binding of the NH2-terminal disulfide bond of fibrin with fibrinogen]. / Vliianie peptidov--strukturnykh analogov NH2 kontsevykh uchastkov alpha- i beta-tsepei fibrina--na spetsificheskoe sviazyvanie NH2-kontsevogo disul'fidnogo uzla fibrina s fibrinogenom.

Peptides Gly-Pro-Arg-Pro and Gly-His-Arg-Pro (fibrin alpha- and beta-chain NH2-terminal analogs, respectively) are studied for their effect on fibrinogen (F) and fibrin NH2-terminal disulphide knot (N-DSK) specific binding. Both peptides are found to inhibit the formation of soluble and insoluble F-N-DSK-complexes through inhibition of the interdomain D-E-binding. Gly-Pro-Arg-Pro is much more potent inhibitor than Gly-His-Arg-Pro. Lowering the insoluble F-N-DSK-copolymer quantity by concentration-dependent way these peptides do not change its composition described by the formula [F(N-DSK)2]n. Invariability of fibrinogen and N-DSK copolymer structure is asserted. In this structure neighbouring fibrinogen molecules are bound by two N-DSK molecules via the D1-E1 and D2-E2 binding sites.

[Toxicological characteristics of disodium salt of N-lauroyl-L-glutamic acid--a surface-active agent used in the food processing industry]. / Toksikologicneskaia kharakteristika dinatrievoi soli N-lauroil-L-glutaminovoi kisloty--poverkhnostno-aktivnogo veshchestva dlia pishchevoi promyshlennosti.

To synthesize the disodium salt of N-lauroyl-L-glutamic acid (LG-Na2), use was made of the chloranhydride method with some modifications. The yield of the product was 85%. LG-Na2 possesses good surface-active properties and an emulsifying effect. The critical concentration of micelloformation of LG-Na2 is 6 10(-3) mol/l. LG-Na2 is a non-toxic compound. It is not cumulated in the animals' body. The LD50 for albino rats per os exceeds 10 000 mg/kg, that for mice 6500 mg/kg. It was shown in subacute experiments in rats that LG-Na2 did not produce any substantial influence on the animals' status or on some biochemical and morphological indicators of blood and organs. The authors suggest a tentative level of a safe oral action of LG-Na2 on man (10 mg per kg bw/day). LG-Na2 is likely to be widely used in food industry.

[Removal of surface-active substances from proteins by reversible immobilization on water-insoluble carrier]. / Osvobozhdenie belkov ot poverkhnostio-aktivnykh veshchestv metodom obratimoí immobilizatsii na nerastvorimom nostitele.

Techniques for removing of surface-active substances from cysteine and cystine-containing proteins preliminarily immobilized by thiol-disulfide exchange on water-insoluble carrier, followed by protein transfer into solution, as examplified in sodium dodecyl sulfate, cetyltrimethylammonium bromide and bovine serum albumin are described. This procedure may be used to remove any sort of material non-covalently bound to protein.