Journal ArticleDOI
Metabolism of delta24-sterols by yeast mutants blocked in removal of the C-14 methyl group.
TLDR
Investigation of the metabolism of exogenously provided delta24-sterols by whole cell cultures of a polyene-resistant mutant of Candida albicans blocked at removal of the C-14 methyl group indicated that zymosterol was a better (40 X) substrate than endogenous lanosterol.Abstract:
We have investigated the metabolism of exogenously provided Δ24-sterols by whole cell cultures of a polyene-resistant mutant (D10) of Candida albicans blocked at removal of the C-14 methyl group. Comparison of the relative efficiencies of transmethylation at C-24 of selected sterol substrates revealed the following substrate preferences of the Candida Δ24-sterol methyltransferase (EC 2.1.1.41): zymosterol > 4α-methylzymosterol > 14α-methylzymosterol. Exogenous 4,4-dimethylzymosterol was not transmethylated by mutant D10. Incorporation of the 14C-labelled methyl group of S-adenosyl-L-[methyl-14C]methionine into the sterols of a D10 culture preloaded with zymosterol indicated that zymosterol was a better (40 ×) substrate than endogenous lanosterol. Feeding zymosterol to D10 and a polyene-resistant strain of Saccharomyces cerevisiae (Nys-P100) that was also blocked at removal of the C-14 methyl group gave 24-methyl sterols possessing Δ22 and ring B unsaturation. Mutant D10 was able to produce ergosterol from...read more
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Journal ArticleDOI
Sterol structure and membrane function.
TL;DR: In this paper, Sterol, Structure and Membrane Function (SSTF) is used to describe the structure and function of Membranes in the human brain. Critical Reviews in Biochemistry: Vol. 14, No. 1, pp. 47-92.
Journal ArticleDOI
Structural and physiological features of sterols necessary to satisfy bulk membrane and sparking requirements in yeast sterol auxotrophs.
Russell J. Rodriguez,L. W. Parks +1 more
TL;DR: Data are extended to hypothesize a role for the C-28 methyl group of ergosterol in yeast to satisfy bulk membrane and high-specificity (sparking) functions in three yeast sterol auxotrophs.
Journal ArticleDOI
Sterol requirements and paclobutrazol inhibition of a celery cell culture
TL;DR: The results reveal that the celery cells have two requirements for sterols, one is for relatively large amounts of sterol and may be associated with membrane elaboration and the other essential role, termed ‘trigger’, requires trace amounts of Sterol with a 24α-ethyl side chain such as stigmasterol.
Journal ArticleDOI
A mutant of Ustilago maydis deficient in sterol C-14 demethylation: Characteristics and sensitivity to inhibitors of ergosterol biosynthesis☆
Rosemary C. Walsh,Hugh D. Sisler +1 more
TL;DR: Findings support the contention that inhibition of sterol C-14 demethylation in U. maydis is the primary mode of toxicity of fenarimol, etaconazole, and miconazole.
Journal ArticleDOI
Requirement for a second sterol biosynthetic mutation for viability of a sterol C-14 demethylation defect in Saccharomyces cerevisiae.
TL;DR: Growth studies with a sterol auxotrophic strain indicated that the major sterol of strain JR4, 14 alpha-methyl-ergosta-8,24(28)-dien-3 beta-ol, could satisfy "bulk" membrane requirements but not the second, structurally specific, sterol function that was defined previously.