[Novel Immobilized Biocatalyst for Microbiological Synthesis of Pharmaceutical Steroids].

The steroid-transforming activity of free and immobilized cells of Pimelobacter simplex VKPM As-1632 entrapped in an operationally stable macroporous polyvinyl alcohol cryogel was studied. It was shown that the macroporous matrix of the carrier did not create any diffusional limitations for steroid access to the cells or the removal of the transformation products from them. The optimal conditions for the hydrocortisone 1,2-dehydration into prednisolone by free and immobilized cells were elucidated.

[Transformation of delta4-3-ketosteroids by free and immobilized cells of Rhodococcus erythropolis actinobacterium].

9alpha-Hydroxy derivatives were prepared from 11 steroids ofandrostane and pregnane series using Rhodococcus erythropolis VKPM Ac-1740 culture with 0.5-20 g/l substrate concentration in the reaction mixture. 9alpha-Monohydroxylation proceeded regardless of the substituent structure at C17.

[Adsorptive immobilization of rhodococcal cells in hydrophobized derivatives of wide-pore polyacrylamide cryogel].

Adsorption of Rhodococcus ruber cells on columns with polyacrylamide cryogel (CryoPAAG) partially hydrophobized by different quantities (0.2, 1, and 5 mol %) of chemically grafted n-dodecane residues has been studied. The adsorption capacity (1.

[Biocatalytic properties of thermolysin immobilized on polyvinyl alcohol cryogel].

Preparations with different contents of thermolysin were obtained by the immobilization of the enzyme on granulated polyvinyl alcohol cryogel. Their activity and stability in an aqueous medium and in mixtures of polar organic solvents of different composition were investigated. The catalytic properties of the preparations in reactions of peptide bond formation were studied, and the optimal amount of the biocatalyst, the concentrations of initial reagents, and the ratios of organic solvents and water necessary for effective enzymatic peptide synthesis catalyzed by immobilized thermolysin were determined.

[Subtilisin Carlsberg in complex with sodium dodecyl sulfate--an effective catalyst for the solid phase segment coupling of peptides on polyvinyl alcohol cryogel].

Subtilisin Carlsberg (SK) was shown to catalyze the solid phase segment coupling of peptides in complex with sodium dodecyl sulfate (SDS) in an organic medium on Aminosilochrom and polyvinyl alcohol (PVA) cryogel activated with glutaraldehyde or divinylsulfone. Diamines of different lengths with a general formula NH2-(CH2)n-NH2 (n = 2, 4, and 6) were used as spacers between the PVA cryogel and the peptide. A model reaction of enzymatic attachment of the Dnp-Ala-Ala-Leu-OMe tripeptide to the PVA cryogel was carried out by treatment with the SDS-SK complex in a mixture of anhydrous ethanol and DMSO (7: 3, v/v) using a tenfold excess of the carboxyl component.