[Blood coagulating properties of the copperhead Agkisrodon halys halys venom and its thrombin-like fractions].

Venom and its fraction with hemocoagulation properties from Agkistrodon halys halys exhibited dissimilar effects on blood plasma and fibrinogen preparation. The major component of this fraction proved to be a thrombin-like enzyme, properties of which were studied by means of several coagulation tests. Dissimilarity in coagulating effects of the venom and its thrombin-like fraction as well as different physical properties of blood clots formed after their action suggest that the venom from Agkistrodon halys halys contained other protein factors affecting blood coagulation besides the thrombin-like proteases.

[Isolation and characteristics of a nerve growth factor from the venom of the Central Asiatic viper Echis multisquamatus].

The nerve growth factor (NGF) was isolated from the Echis multisquamatus venom by ultrafiltration on PM-10 filter, chromatography on TSK-55 gel, ion-exchange chromatography on CM-cellulose and gel filtration on Sephadex G-75. The protein exhibited a marked nerve growth activity within the concentration range of 10-15 ng/ml in cultures of chicken embryo spinal ganglia. The molecular mass of NGF is equal to 33,000-37,000 Da according to Sephadex G-75 gel filtration data; however, according to SDS electrophoresis data its Mr is 13,000 Da.

[The use of Soviet substitutes for batroxobin in the determination of fibrinogen].

Plasma fibrinogen was measured by kinetic photometry with two Soviet analogs of the foreign agent batroxobin: ancistron-N and agichal, obtained from Central Asian Aspidelaps lubricus venom by different techniques. Both the preparations of thrombin-like enzyme from the venom have proved to be adequate substituents of batroxobin; the optimal concentration of ancistron-N for this test was found to be 20 micrograms/ml or 0.04 U/ml, that of agichal 0.

[Classification and identification of toxic polypeptides using a pattern recognition method].

A crucial rule for both rapid identification and classification of toxins by the relative content of the five most informative amino acids (glycine, cysteine, threonine, alanine and tryptophane) was established by using a computer algorithm of pattern recognition based on amino acid sequences of three families of toxic polypeptides.

[Therapeutic effect of purified components of a turtle spleen extract].

The administration of a spleen extract of Testudo horsfieldi to mice exposed to lethal radiation of 8 Gy was shown to increase the survival rate and to stimulate haemopoiesis and formation of endocolonies in the spleen. The gel filtration method was used to obtain an active fraction which was subjected to chromatography on cation exchanger to give two more fractions. Active was the fraction with basic components.

[Changes in the membrane surface charge and the potentiation of phospholipase A2 as affected by the cytotoxin from the venom of the Central Asian cobra].

The interaction of iodine labelled cytotoxin of the middle-asian cobra venom with erythrocyte membranes has been studied. The pretreatment of erythrocytes by cytotoxin results in the sensitivity to the lytic action of pure phospholipase A2 of the same venom. Using I-labelled serum albumin it has been proved that cytotoxin promotes the binding of acid proteins on the membrane such as phospholipase A2 interacted with it synergetically.

[Effect of the cytotoxin of Central Asia cobra venom on the functional state of rat liver mitochondria].

A study was made of the action of various concentrations of cytotoxin (C), free of phospholipase A admixtures, on the respiration, oxidative phosphorylation of the rat liver mitochondria and their "ghosts", and also on the permeability of their internal membranes for various ions. Low C concentrations (10--25 micrometer) failed to influence the functional parameters of the intact mitochondria, but sharply increased the permeability of the internal membranes for monovalent ions. Apparently the uncoupling action of C on the mitochondrial "ghosts" was caused by the formation in the membrane of nonspecific conductivity "canals" with poor selectivity to the ion size and charge.

[Heat denaturation of hemocytocardiotoxin from the venom of the Central Asian cobra].

It has been stated that boiled for three hours haemocytocardiotoxin (HT) from cobra poison loses "direct" hemolytic activity and is unable to potentiate a haemolytic effect of phospholipase A. Surface activity of HT does not change. It is shown that in the course of heat denaturation the aggregation of toxin molecules to dimers and trimers takes place and electrophoretic mobility is decreased.

[Role of calcium ions and fatty acids in the inhibition of Mg2+, Na+ and K+-ATPases by means of the "direct" hemolysin and phospholipase A of cobra venom].

The influence of calcium ions and fatty acids in the action of direct hemolytic factor and phospholipase A on Mg2+ and Na+, K+-ATPases was investigated. It was established that calcium activates greatly phospholipase A and to a less extent--the direct hemolytic factor. The activity of ATPases is inhibited most effectively by the system consisting of phospholipase A, direct hemolytic factor and Ca2+.