[Application of the ultrafiltration method to the isolation of cholesterol oxidase of microbial origin]. / Primenenie ul'trafil'tratsionnogo metoda dlia vydeleniia kholesterinoksidazy mikrobnogo proiskhozhdeniia.

Ultrafiltration of solutions of intracellular cholesterol oxidase of Actinomyces lavendulae through semi-permeable membranes (N-vinyl pyrrolidone and methacrylate copolymers) of varying porosity and acetyl cellulase ultrafilter UAM-200 M was investigated. The ultrafiltration through membranes of both types involved both concentration and purification of cholesterol oxidase from low molecular weight protein admixtures. When copolymer membranes were used, their performance and degree of purification were higher and losses were lower than in case of UAM-200 M filter. The optimum hydrolytic mode of ultrafiltration of intracellular cholesterol oxidase through both filters was determined.

[Conditions for isolation of cholesterol oxidase from Actinomyces lavendulae mycelia]. / Izuchenie uslovii vydeleniia kholesterinoksidazy iz mitseliia Actinomyces lavendulae.

The isolation conditions, composition and certain properties of cholesterol oxidase from the mycelium Actinomyces lavendulae were studied. Selective extraction of the enzyme occurred upon the mycelium extraction by the Tween-80 containing buffer. The specific activity of cholesterol oxidase thus obtained exceeded seven-fold that of the enzyme isolated via other methods. The optimal concentration of the detergent upon extraction was 0.15%. By disc-electrophoresis it was demonstrated that the preparation isolated from disrupted cells contained, in addition to cholesterol oxidase, 16 other protein components that had no enzymatic activity whereas the Tween-80 extracted preparation included no more than 7 fractions. The study of the relationship between activity of the resultant cholesterol oxidase and the substrate concentration and pH demonstrated that optimal conditions for the enzyme action were at pH 7.0-7.5 and cholesterol oxidase concentration of 0.0316 mM.

[Permeability of acetylcellulose ultrafiltration membranes with regard to biologically active substances]. / Pronitsaemost' atsetiltselliuloznykh ul'trafil'tratsionnykh membran po otnosheniiu k biologicheski aktivnym veshchestvam

The permeability of standard Soviet ultrafiltration membranes prepared from cellulose acetates was investigated with respect to biologically active substances (hemoglobin, trypsin, ribonuclease, vitamin B12, hydroxytetracycline) and inorganic salt (KH2PO4). The arrest of a substance by a membrane of a certain structure depended primarily on the size of the substance macromolecule in the solution. The filtration rate was related to the membrane type, pressure gradient and composition of the filtered solution. Potential use of the tested membranes is described.

[Complex-formation between myeloperoxidase and fibronectin and its modulation by fibronectin ligands]. / Kompleksoobrazovanie mieloperoksidazy i fibronektina i ego moduliatsiia ligandami fibronektina.

Human blood plasma fibronectin immobilised on agarose in physiological interacts with soluble myeloperoxidase (Kd = 2.43 mM). Interaction of myeloperoxidase with fibronectin adsorbed on immobilised gelatin a, natural fibronectin ligand, resulted in formation more stable complex (Kd = 0.94 mM). The presence of thermoaggregated (but not native) IgG in the liquid phase increased a stability of the complex (0.06 mM). It is suggested that myeloperoxidase could represent a component of complex super molecular structure, real immune complex.

[Composition and properties of cholesterol oxidase from Actinomyces lavendulae]. / Issledovanie komponentnogo sostava i svoistv kholesterinoksidazy Actinomyces lavendulae.

The composition of cholesterol oxidase isolated by different methods from the Actinomyces lavendulae mycelium was studied by gel-chromatography. It was shown that depending on the isolation conditions the enzyme can be detected within the complexes with different molecular weights. The values of pH, pI and Km for the isolated components were determined. The thermal inactivation of the cholesterol oxidase components at different temperature intervals was investigated.

[Thermodynamic parameters of complex formation of blood plasma fibronectin and myeloperoxidase]. / Termodinmicheskie parametry kompleksoobrazovaniia fibronektina plazmy krovi i mieloperoksidazy.

Previous studies have demonstrated that fibronectin immobilized on BrCN-activated agarose forms a complex with soluble myeloperoxidase. The affinity of such interaction increases after preliminary absorption of fibronectin on a column with immobilized gelatin, one of its natural ligands. The thermodynamic characteristics of the myeloperoxidase interaction with fibronectin-gelatin-agarose have been established. The role of fibronectin-myeloperoxidase interaction in the inflammation focus is discussed in terms of the mode of the phagocyte loading with the enzyme and as a way of protecting intrinsic body tissues from injury by oxidants generated by extracellular myeloperoxidase.