Biomaterial Database

Identification of 24-methylene-24,25-dihydrolanosterol as a precursor of ergosterol in the yeasts Schizosaccharomyces pombe and Schizosaccharomyces octosporus. 1995

N Harmouch, and J Coulon, and R Bonaly

Laboratoire de Biochimie Microbienne, G.E.V.S.M., Université Henri Poincaré, Nancy l. Faculté de Pharmacie, France.

Study of the plasma membrane sterol composition in the yeasts Schizosaccharomyces pombe and Schizosaccharomyces octosporus revealed the presence of ergosterol, lanosterol, dehydroergosterol, fecosterol, episterol and 24-methylene-24,25-dihydrolanosterol (eburicol), a C-31 derivative. The growth of both yeasts in the presence of ketoconazole led to a decrease by 85% of the ergosterol content while the levels of lanosterol and eburicol increased. This suggests that in the biosynthetic pathway of ergosterol in Schizosaccharomyces species, the transmethylation process on the C-24 may occur directly on lanosterol and not only on zymosterol. On the other hand, it cannot be excluded that in the genus Schizosaccharomyces two routes exist from lanosterol to ergosterol: the classical one via a direct C-14, C-4 demethylation of lanosterol and the second one via the formation of a C-31 derivative followed by demethylations.

UI	MeSH Term	Description	Entries
D007654	Ketoconazole	Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients.	Nizoral,R-41400,R41,400,R41400,R 41400
D007810	Lanosterol	A triterpene that derives from the chair-boat-chair-boat folding of 2,3-oxidosqualene. It is metabolized to CHOLESTEROL and CUCURBITACINS.	Kryptosterol,4,4,14 alpha-trimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004875	Ergosterol	A steroid occurring in FUNGI. Irradiation with ULTRAVIOLET RAYS results in formation of ERGOCALCIFEROL (vitamin D2).	Lumisterol,Pro-Vitamin D2,Provitamin D 2,D2, Pro-Vitamin,Pro Vitamin D2
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012568	Schizosaccharomyces	A genus of ascomycetous fungi of the family Schizosaccharomycetaceae, order Schizosaccharomycetales.	Fission Yeast,Schizosaccharomyces malidevorans,Schizosaccharomyces pombe,Yeast, Fission,S pombe,Fission Yeasts
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013261	Sterols	Steroids with a hydroxyl group at C-3 and most of the skeleton of cholestane. Additional carbon atoms may be present in the side chain. (IUPAC Steroid Nomenclature, 1987)	Sterol