The mycobacterial lipoglycans, lipomannan (LM) and lipoarabinomannan (LAM), are potent
immunomodulators in tuberculosis and leprosy. Little is known of their biosynthesis, other
than being based on phosphatidylinositol (PI), and they probably originate in the
phosphatidylinositol mannosides (PIMs; PIMans). A novel form of cell-free incubation
involving in vitro andin situ labeling with GDP-[14 C] Man of the polyprenyl-P-mannoses (C
35/C 50-P-Man) and the simpler PIMs of mycobacterial membranes, reisolation of the [14 C] …