STUDIES ON THE DELTA-5-DESATURATION IN ERGOSTEROL BIOSYNTHESIS IN YEAST

  • 1 January 1979
    • journal article
    • research article
    • Vol. 85  (3) , 819-826
Abstract
The .DELTA.5-desaturation reaction in ergosterol biosynthesis was studied with a particulate fraction of cell-free extract of yeast. A reduced pyridine nucleotide coenzyme and molecular O2 were required for the reaction. 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. .DELTA.5-Desaturation apparently involves a mixed function oxidase system resembling that for the fatty acyl-CoA desaturation reaction.