The functional importance of structural features of ergosterol in yeast.

摘要: As an approach to the study of relationship between structure sterols and their capacity function in lipid leaflet membranes, various were examined for ability support growth anaerobic Saccharomyces cerevisiae. A marked dependence on precise structural features was observed growth-response morphology. Of chemical groups which distinguish ergosterol, main sterol S. cerevisiae, hydroxyl group at C-3 obligatory, other found be following relative importance: 24beta-methyl-delta22-grouping greater than 24beta-methyl delta5,7-diene system = delta5-bond approximately or equal no double bond. Methyl C-4 C-14 inconsistent with activity. Consequently, data strongly suggest that normal biosynthetic processes removal methyl from nucleus introduction one side chain are functional significance. bond C-17 C-20 joining steroidal had deleterious effect process but only if C-22 trans-oriented C-13. In cis-case all proceeded. This means natural probably acts functionally form its preferred conformer is right ("right-handed") usual view. Since placing a substituent (OH CH3) molecule such way it appears front right-handed completely destroyed activity, apparently presents face protein phospholipid when complexing occurs.