Structure of the glycosyl-phosphatidylinositol membrane anchor of the Leishmania major promastigote surface protease

Abstract

In common with many other plasma membrane glycoproteins of eukaryotic origin, the promastigote surface protease (PSP) of the protozoan parasite Leishmania contains a glycosyl-phosphatidylinositol (GPI) membrane anchor. The GPI anchor of Leishmania major PSP was purified following proteolysis of the PSP and anaylzed by two-dimensional 1H-1H NMR, compositional and methylation linkage analyses, chemical and enzymatic modifications, and amino acid sequencing. From these results, the structure of the GPI-containing peptide was found to be Asp-Gly-Gly-Asn-ethanolamine-PO 4-6Manα1-2Manα1-6Manα1-4GlcNα1-6myo-inositol- 1-PO4-(1-alkyl-2-acyl-glycerol). The glycan structure is identical to the conserve..