Biosynthetic preparation of labeled 4,4-dimethylzymosterol.

Labeled 4,4-dimethyl-5 alpha -cholesta-8,24-dien-3 beta-ol (4,4-dimethylzymosterol) was prepared by incubating labeled mevalonate with rat liver extracts in the presence of arsenite and lanosterol.

Isolation and characterization of an altered cytochrome P-450 from a yeast mutant defective in lanosterol 14 alpha-demethylation.

A cytochrome P-450 (P-450SG1) was purified from a lanosterol 14 alpha-demethylase (P-450(14DM)) defective mutant of Saccharomyces cerevisiae, strain SG1, by a method similar to that used in the purification of the wild type enzyme (Yoshida, Y., and Aoyama, Y. (1984) J.

Spectral properties of a novel cytochrome P-450 of a Saccharomyces cerevisiae mutant SG1. A cytochrome P-450 species having a nitrogenous ligand trans to thiolate.

An altered cytochrome P-450 (SG1 P-450) was partially purified from Saccharomyces cerevisiae mutant SG1 which is defective in lanosterol 14 alpha-demethylation. Oxidized SG1 P-450 showed a Soret peak at 422 nm and the alpha peak was lower than the beta peak. This spectrum was considerably different from those of known low-spin P-450s, indicating a unique ligand structure of SG1 P-450.

Altered cytochrome P-450 in a yeast mutant blocked in demethylating C-32 of lanosterol.

Spectroscopic and enzymatic analysis of a Saccharomyces cerevisiae mutant in sterol biosynthesis (SG1 (erg 11); Trocha, P. J., Jasne, S.