The role of cholesterol in mycoplasma membranes.

摘要: Cholesterol is the end product of sterol biosynthetic pathway in animal cells. The molecule arose necessarily with advent an aerobic environment (Bloch, 1983), making it a relative latecomer evolutionary development living Perhaps, as consequence, sterols are not uniformly distributed among life forms are, say, amino acids and nucleic acids, but reserved almost without exception membrane components eukaryotic rather than prokaryotic Notable exceptions to exclusionary rule prokaryotes can be found few bacteria (Bird et al., 1971) members class Mollicutes. Of three established families comprising Mollicutes, Mycoplasmataceae Spiroplasmataceae require cholesterol or related for growth whereas Acholeplasmataceae do not. None mycoplasmas* synthesize de novo, nor they generally metabolize modify molecule. Rather, mycoplasmas incorporate unchanged from levels approaching 50 mole% total lipid. These features coupled mycoplasmas’ inherent fatty acid auxotrophy single structure assure high rank organisms choice studies aimed at understanding role natural membranes. degree control over lipid content one achieve more closely approaches that obtained model membranes most other systems used study structure-function relationships such yeast, insects, fibroblasts. Although on have provided valuable information functional consequences sterol-phospholipid interactions, principles governing both sterol-protein interactions complex milieu must ultimately delineated before full cells reached.