Author/Editor		Lanišnik-Rižner, Tea
Title		Izolacija in karakterizacija 17beta-hidroksisteroidne dehidrogenaze iz glive Cochliobolus lunatus
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1996
Volume		str. 101
Language		slo
Abstract		17beta-HSD are oxidoreductases that catalyze interconversions of androgens and estrogens. Mammalian 17beta-HSD are involved in biosynthesis of androgens and estrogens in classical steroidogenic tissues as well as in the regulation of the concentrations of biologically active sex hormones in peripheral tissues. Mammalian 17beta-HSD and bacterial 3beta,17beta-HSD from Pseudomonas testosteroni are well characterized enzymes while fungal 17beta-HSD are less known. The only fungal 17beta-HSD purified so far is inducible 17beta-HSD from Cylindrocarpon radicola. The existence of constitutive 17beta-HSD activity in fungi was first demonstrated in the fungus Cochliobolus lunatus by co-workers at the Institute of Biochemistry at the Ljubljana Medical Faculty. Later, the steroid binding proteins as well as the endogenous biosynthesis of testosterone were proven in the same fungus by the same authors. Constitutive 17beta-HSD from Cochiliobolus lunatus was purified by ammonium sulphate precipitation, gel (Sephacryl S-300) and affinity chromatography (2'5'ADP Sepharose). The specific activity of 40 micromol of product/mg of protein h was achieved by 1873-fold purification resulting in a yield of 32%. 17beta-HSD from Cochliobolus lunatus was found to be a dimer with a molecular weight of 28 297 Da. The N-terminal and a partial amino acid sequence after proteolysis with Lys-C and Glu-C were determined, altogether 134 amino acids. Results of a similarity search indicate that 17beta-HSD from Cochliobolus lunatus is a member of the short-chain alcohol dehydrogenase (SCAD) protein family. The highest homology was found with fungal enzymes: 66% with ketoreductase from Aspergillus parasiticus and 59% with tetrahydroxynaphtalene reductase from Magnaphorthe grisea. (Abstract truncated at 2000 characters).
Descriptors		ASCOMYCETES 17-HYDROXYSTEROID DEHYDROGENASES CYTOSOL CHROMATOGRAPHY, GEL CHROMATOGRAPHY, AFFINITY AMINO ACID SEQUENCE IMMUNOCHEMISTRY MOLECULAR WEIGHT