Phenyl phosphate as a water-soluble analog of dolichyl phosphate in microsomal mannosyltransferase systems.

摘要: Incubation of rat liver microsomes with GDP-[14C]mannose and phenyl phosphate for 30 min, followed by paper-chromatographic analysis, revealed the presence a new radioactive compound that was isolated characterized as beta-D-mannosyl phosphate. The enzyme catalyzing this reaction very closely related to dolichyl phosphate-synthesizing activity found in same microsomes. two activities were affected parallel fashion mild heating proportions whole microsomes, rough-surfaced smooth-surfaced mirosomes. Increasing concentration from 0 15 mM resulted progressive reduction rate mannose incorporation into endogenous It is concluded reactions are catalyzed single enzyme. labeled product rapidly excluded while retained suggesting may act mannose-trapping agent, thereby inhibiting mannosyltransferase involving glycosyl carrier.