[Thrombin and anticoagulant therapy].

New data which reveal rational approaches for pharmacologic control of blood coagulation process and confirm the key role of thrombin in haemostasis processes compared with other proteinases are presented in the review. Modulation of thrombin properties described in the review gives a new possibility for creating anti-thrombin preparations. Thrombin allosteria can serve a basis for development of new therapy.

[Sodium ions as the effector of catalytic action of alpha-thrombin].

A process of thrombin interaction with synthetic and natural substrates in the presence of Na+ ions has been analyzed in the survey. Molecular bases of this interaction have been presented, interrelation between the structure and function of thrombin has been noted; the nature of the unique site of its active centre which determines high thrombin affinity for the substrates and increase of its catalytic activity defined by the term of "specificity to univalent cations" have been considered in detail. Na+ ions play the role of allosteric effector in realization of two informational states of thrombin which penform, respectively, two fundamental and competing functions in the process of hemostasis.

[Human thrombin: drug stability and stabilization].

Stabilization of enzymes is a key factor when using biocatalysis in practice. Each enzyme stability depends both on the structure of its molecule and on the effect of various environmental factors, thus, one of the methods of the enzyme stability preservation is the formation of optimal macromedium. Thus, water structure and enzyme hydration change in the presence of solvable additives that affects its stability and catalytic properties.

[Interrelation between thrombin structure and its stability].

Temperature inactivation of human thrombin has been studied when finding out the mechanism of this enzyme stabilization by amino acids. Effect of a number of amino acids on thrombin in the conditions (pH) of the highest activity of proteinase has been investigated. It is established that most amino acids are characterized to more or less extent by the protective action, when hampering the temperature inactivation of the enzyme.

[Interaction of human alpha-thrombin with organic ligands of ionic nature].

Investigations results of human thrombin interaction with organic ligands of ion nature containing nonpolar groups are presented. It is shown that electrostatic interaction is the basic one under enzyme binding, while hydrophobic binding is only additional function in the reaction enzyme-ligand, this fact is confirmed by the absence of interaction between thrombin and rivanol which has a positive charge side by side with cumbrous hydrophobic group. New data are presented about the ligand specificity of binding sites of thrombin active centre.

[Interrelation between thrombin structure and its stability].

Data concerning peculiarities of fermentative nature and structure of thrombin in water-salt solution have been generalized; regularities of stabilizing effect made on thrombin by various polyols and other substances have been analyzed. It has been shown that formation of thrombin optimum macrostructure is one of the methods of its stabilization. Presence of different dissolving additives changes this enzymes hydration and this affects its stability and activity.

[Human thrombin: enzymatic properties, stability and standardization of preparation].

The work deals with estimation of thrombin preparation having such features as: sedimentation activity 3000-3200 NIH un. per 1 mg of protein and 97% of active centres. The enzyme isolated has been estimated according to the amidolytic activity on synthetic substrates S-2160 and BAPNA being equal 5200 and 185 milli un/mg of protein, respectively.

[Binding of Kunitz-Northrop inhibitor on some sorbents].

This work is devoted to the problem of sorption and desorption of Kunitz--Northrop inhibitor on different sorbents. By passing through Dowex 1.10 column 0.

[Polypeptide serine proteinase inhibitors isolated from venom from several reptilian species].

The survey encompasses literature data on the polypeptide inhibitors of some reptiles serine proteinases and their separation from adder Viperidae and cobra Elapidae species. The evolutionary comparison of physico-chemical and biological properties of them are also given and discussed within this work. Considerable homology (about 50%) in amino acid composition of adder, bee, mammal and others of different phylogenetic origin is being emphasized and high homology in structure of their functionally important inhibitors sites is observed.

[Isolation and properties of fish chymopsin].

A simple and convenient method of fish chymopsin isolation from the acetone powder of pyloric appendices has ben developed using classical methods. The enzyme preparation includes 62-65% of protein, the specific weight of trypsin and chymopsin being 1000 and 3000 units per 1 mg of protein, respectively. Heterogeneity of the isolated chymopsin was shown using electrophoresis in PAAG.

[Role of S'2-stimulation of serine proteases in regulation of proteolysis].

Data about ligand specificity and functionality of the nearest surrounding of hydrolytic centre of serine proteases are presented. A regulatory role of S'2-site predetermining highly-specific activation of proenzymes into the enzymes and formation of stable enzyme-serine complexes is discussed.

[Peptide hydrolases of marine organisms].

The survey is devoted to the description of properties of proteolytic enzymes of some sea organisms. Structure peculiarities and properties of proteinases of trypsin and chymotrypsin type, carboxypeptidases A and B, aminopeptidase and leucine aminopeptidase of molluscs, stars, shrimps, fishes and other sea organisms have been considered. Data are presented about trypsins typical of the sea organisms which are characterized by high content of asparaginic and glutaminic acids and small values of activation energy of the reactions which they catalyse.

[Hydrophobic interactions of serine proteases with low molecular weight compounds: partial effector displacement from the activated enzyme by the substrate].

1,2,3-tris-tri-beta-phenylethylaminopropane (a compound which can simultaneously interact with S1- and S2'-enzyme sites and has complicated grouping in the region analogous to "leaving group" of a substrate) has been studied for the effect on chymotriptic hydrolysis. Anomalously high inhibitory effect of some cumbersome organic compounds is explained on the base of the obtained data.

[Hydrophobic interactions of serine proteases with low molecular compounds: role of the S'2-site in substrate activation and interaction with serpines].

An attempt is made to simulate the P1-P'2 site of the reactive centre of protein inhibitors of serine proteases (serpines). On the basis of data from literature structure requirements are formulated and compound 1,5 bis-dibenzyl-aminopentane is synthesized. It may simultaneously interact with S1- and S'2-sites of chymotrypsin and contains no bonds adequate to the hydrolytic centre of proteinase.

[Enzyme activity and lipids of a preparation from the pyloric ceca of salmon].

Proteolytic activity and lipid composition of enzymic preparations of water extract from the pyloric caeca of salmon fishes have been studied. Phospholipids and sterols are tightly bound with proteins. The participation of lipids in the proteolytic activity is discussed.

[Comparative study of the properties of serine proteases of lower and higher vertebrates].

Results of the comparative study of trypsin- and chymotrypsin-like serine proteases from pyloric caeca of salmon fishes and trypsin and chymotrypsin of bulls are presented in the paper. The hydrolytic activity of salmon proteases with respect to methyl ethers of N-benzoyl-L-leucine is 2.4 times higher than that of bull chymotrypsin, but with respect to methyl esters of N-benzoyl-L-tyrosine and N-benzoyl-L-arginine the activity of salmon proteases is 6.

[Hydrophobic interaction of alpha-chymotrypsin with low molecular weight compounds].

Data on alpha-chymotrypsin interactions with hydrophobic low-molecular compounds have been generalized. Existence of two sites of noncovalent interaction with hydrophobic nuclei of a ligand molecule is shown. When the substance to be bound contains only one hydrophobic nucleus, the interaction is mediated by a "hydrophobic pocket" of the enzyme--a binding site of amino acid residues which are, in the P1-position relative to the cleaved bond.

[Preparation and properties of trypsin from the pyloric caeca of Pacific Ocean salmon].

Trypsin from pyloric caeca of Pacific salmon was purified by affinity chromatography of the water extract on hexamethylenediamine-glycidylmethacrylate-cellulose. A protein band with a molecular weight of 22.5 kDa was found on SDS-electrophoresis in PAG.

[Trypsin-, chymotrypsin-like proteinases in fishes].

Recent data on the nature of trypsin-, chymotrypsin-like proteinases of fish are generalized. Localization and secretion of these enzymes in pyloric appendages of fish are considered in detail. Trypsin and chymotrypsin are in the state of proenzymes and transform into the active form by means of their own proteolytic factors.

[Serine proteinases of lower vertebrates].

Recent data on the effect of serine proteinases of lower vertebrates are generalized. Hydrolysis specificity and kinetics of different synthetic substrates, dependence of the activity of enzymes on pH, their irreversible inhibition by chloromethyl ketones of amino acids and peptides as well as high-molecular proteinase inhibitors are considered in detail. The data testify to the fact that chymotrypsins and trypsins of higher vertebrates and serine proteinases of lower vertebrates act as an acid-base catalysis.

[Isolation and properties of enzyme preparations from the whale pancreas].

A simple and convenient technique was developed for isolation of the proteolytic enzyme complexes from the whale (Balaenoptera) pancreas. The proposed techniques enables the proteolytic complexes to be obtained with the protein yield 2.6 times higher than the classical procedure.

[Affinity chromatography of aminopeptidases].

The recent data are generalized concerning a series of synthetic oligopeptides which are competitive inhibitors of aminopeptidases of animal, plant and microbic origin. A method for biospecific chromatography of these enzymes is developed, using as ligands such inhibitors as diazo derivatives of p-aminophenyl-, chloromethyl- and methylketones of L-amino acids and peptides, amino acids, aliphatic acid amides. It is established that the most effective inhibitors of aminopeptidases contain L-amino group in the uncharged form in the N-end position, hydrophobic lateral chain of L-configuration and a carbonyl group analogous to position of these groups in the substrate.