Effects of plasminogen, streptokinase and their equimolar complexes with pyruvate kinase on the human neuroblastoma IMR-32 cells

The system of extracellular proteolysing, consists of plasminogen (PGn), its active protease (plasmin), PGn activation and PGn activators inhibitors, influences the nervous tissue functions, their growth, differentiation and proliferation in both, normal and pathological conditions. The purpose of the investigation was to study the effects of exogenous PGn, its activator streptokinase (SK), PK and their equimolar complex on the morpho-functional state neuroblastoma IMR-32 cells. PGn, SK, PK and their complexes stimulated cells proliferation during 1-3 days of incubation, shown by cell quantity increase. We also observed DNA, RNA and protein increase. The low lactate dehydrogenase efflux was evidence of that an addition of the proteins under investigation in the culture medium prevented the development of degenerative alterations connected with serum deprivation. The levels of extracellular PGn-activator activity, as measured by the biochemical fibrinolytic assay, increased over SK. This SK effect vanished on the 3rd day when SK formed complexes with PK. New original facts obtained testify the probability of initiation of neoplastic transformation and tumor growth potentiation.     

Effect of self-association on the structural organization of partially folded proteins: inactivated actin

The propensity to associate or aggregate is one of the characteristic properties of many nonnative proteins. The aggregation of proteins is responsible for a number of human diseases and is a significant problem in biotechnology. Despite this, little is currently known about the effect of self-association on the structural properties and conformational stability of partially folded protein molecules. G-actin is shown to form equilibrium unfolding intermediate in the vicinity of 1.5 M guanidinium chloride (GdmCl). Refolding from the GdmCl unfolded state is terminated at the stage of formation of the same intermediate state. An analogous form, known as inactivated actin, can be obtained by heat treatment, or at moderate urea concentration, or by the release of Ca(2+). In all cases actin forms specific associates comprising partially folded protein molecules. The structural properties and conformational stability of inactivated actin were studied over a wide range of protein concentrations, and it was established that the process of self-association is rather specific. We have also shown that inactivated actin, being denatured, is characterized by a relatively rigid microenvironment of aromatic residues and exhibits a considerable limitation in the internal mobility of tryptophans. This means that specific self-association can play an important structure-forming role for the partially folded protein molecules.     

Development of the biological preparation enatin with broad-range antimicrobial action

Physiological and biochemical traits of epiphytic spore forming bacteria Bacillus pumilis BIM V-263 were examined. The nutrient medium and conditions for submerged cultivation of the strain were selected. The growth dynamics and antagonistic activity during cultivation in a laboratory fermenter ANKUM-2M were studied. The results provide grounds for development of the biological preparation Enatin with broad-range antimicrobial effect. The plant-protective and growth-stimulating effect of Enatin was examined in laboratory and field experiments. The preparation holds promise as means for biological control of crop pathogens.     

Immobilization of the lytic enzyme complex lysoricephine]

Entrapping of the lysoenzyme complex of lysoricephine in solutions of hydrophilic polymers and its immobilization on dressing materials were performed. Immobilized preparations that retained 80-100% of the lytic activity and stable during storage were obtained. Properties of the immobilized preparations: dependence on pH and temperature, stability in acidic medium, and effect of gamma-radiation were studied. It was shown that coimmobilization with protease C induced a 1.5-1.7-fold increase in the lytic activity of the immobilized preparation compared to the native enzyme complex of lysoricephine.