Enzymatic transfer of mannose from guanosine diphosphate mannose to dolichol phosphate in yeast ( Hansenula holstii) A possible step in mannan synthesis

Abstract

A particulate enzyme fraction isolated from yeast ( Hansenula holstii) catalyzes the transfer of mannose from GDPmannose to endogenous lipid acceptors. Kinetic studies are presented which suggest that one of the mannolipids is a precursor to cell wall mannan. The solubility and chromatographic properties, the stability to mild alkali, and the release of mannose by mild acid hydrolysis are characteristic of polyisoprenyl phosphoryl mannose. Addition of dolichol phosphate to the enzyme system stimulates the synthesis of a mannolipid with properties similar to that synthesized from endogenous lipid. That the exogenous dolichol phosphate was acting as a mannosyl acceptor was demonstrated by showing that dolichol [ 32P]phosphate was converted to dolichol [ 32P]phosphate mannose.