Biosynthesis of Leishmania lipophosphoglycan: elongating and branching galactosyltransferases are depicted using synthetic acceptor substrates

摘要

The protozoan parasite Leishmania infects over 12 million people worldwide, causing a variety of diseases that range from mild cutaneous lesions to fatal visceral infections. Infectious metacyclic promastigotes of Leishmania synthesise lipophosphoglycans (LPGs, the most abundant, surface macromolecules), which contain phosphosaccharide repeats of [-6)(R-3)Gal(β-4)Man(α1-OPO3H-]. In L. donoivani R = H, whereas in L. major R is predominantly β-Gal. It's been demonstrated by Carver & Turco [J. Biol. Chem. 1992, 295, 309] that the LPG backbone is assembled in parasites by sequential addition of Manα1-OPO3H and β-Gal.