O- and N-glycosylation of the Leishmania mexicana-secreted acid phosphatase. Characterization of a new class of phosphoserine-linked glycans.

Abstract

The protozoan parasite Leishmania mexicana secretes a heavily glycosylated 100-kDa acid phosphatase (sAP) which is associated with one or more polydisperse proteophosphoglycans. Most of the glycans in this complex were released using mild acid hydrolysis conditions that preferentially cleave phosphodiester linkages. The released saccharides were shown to consist of monomeric mannose and a series of neutral and phosphorylated glycans by Dionex high performance liquid chromatography, methylation analysis, exoglycosidase digestions, and one-dimensional 1H NMR spectroscopy. The neutral species comprised a linear series of oligosaccharides with the structures [Man alpha 1-2]1-5Man. The phosphoryl..