The high mannose oligosaccharide of phytohemagglutinin is attached to asparagine 12 and the modified oligosaccharide to asparagine 60.
Phytohemagglutinin, the lectin of the common bean Phaseolus vulgaris, has a high mannose and a modified (fucosylated) oligosaccharide on each polypeptide. Fractionation by high performance liquid chromatography of tryptic digests of [(3)H]fucose or [(3)H]glucosamine labeled phytohemagglutinin, followed by amino acid sequencing of the isolated glycopeptides, shows that the high mannose oligosaccharide is attached to Asn(12) and the modified oligosaccharide to Asn(60) of the protein. In animal glycoproteins, high mannose chains are rarely found at the N-terminal side of complex chains.
Sturm
A
A
Department of Biology C-016, University of California, San Diego, La Jolla, California 92093.
Chrispeels
M J
MJ