Direct estimation of dolichyl phosphate in rat liver by high pressure liquid chromatography

A method involving reverse‐phase high pressure liquid chromatography has been developed for determining the concentration of dolichyl phosphate (Dol‐P) in tissues. Individual Dol‐P homologs are resolved and amounts as small as 50 ng can be detected. Rat liver was found to contain 2.4 μg Dol‐P/g wet weight, or ca. 4% of total liver dolichol. In contrast, rat liver microsomes contained 64 ng Dol‐P/mg protein, which is about 40% of total microsomal dolichol. This enrichment in Dol‐P is consistent with the role of microsomes as the major site of Dol‐P‐mediated, glycoprotein biosynthesis in liver