title: Studies on the delta 5-desaturation in ergosterol biosynthesis in yeast.
abstract: Studies were carried out on the delta 5-desaturation reaction in ergosterol biosynthesis with a particulate fraction of cell-free extract of yeast. A reduced pyridine nucleotide coenzyme and molecular oxygen were required for the reaction. It was shown that the enzyme activity is located in a fraction corresponding to microsomes. The reaction was inhibited by KCN, but not by CO. Menadione and potassium ferricyanide inhibited the NADPH- and NADH-dependent reactions, respectively, and cytochrome c inhibited both of them. These results suggested an involvement in delta 5-desaturation of a mixed function oxidase system resembling that for the fatty acyl-CoA desaturation reaction.
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D002248:Carbon Monoxide / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D003574:Cytochrome c Group / Q000494:pharmacology; D004875:Ergosterol / Q000096:biosynthesis*; D005949:Glucose Oxidase / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000494:pharmacology; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009249:NADP / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D014812:Vitamin K / Q000494:pharmacology
chemical_list: D003486:Cyanides; D003574:Cytochrome c Group; D014812:Vitamin K; D006153:Guanosine Diphosphate; D009249:NADP; D002248:Carbon Monoxide; D006899:Mixed Function Oxygenases; D005949:Glucose Oxidase; D001205:Ascorbic Acid; D010100:Oxygen; D004875:Ergosterol