IDENTIFICATION OF THE HUMAN LEWIS(A) CARBOHYDRATE MOTIF IN A SECRETORY PEROXIDASE FROM A PLANT-CELL SUSPENSION-CULTURE (VACCINIUM-MYRTILLUSL.)

This paper reports for the first time the presence of the human Lewis( a) type determinant in glycoproteins secreted by plant cells. A single glycopeptide was identified in the tryptic hydrolysis of the peroxida se VMPxC1 from Vaccinium myrtillus L. by HPLC/ESI-MS. The oligosacchar ide structures were elucidated by ESI-MS-MS and by methylation analysi s before and after removal of fucose by mild acid hydrolysis. The majo r structure determined is of the biantennary plant complex type contai ning the outer chain motif Lewis(a) [GRAPHICS] A corresponding fucosyl transferase activity catalyzing the formation of Lewis(a) type structu res in vitro was identified in cellular extracts of the suspension cul tures. (C) 1997 Federation of European Biochemical Societies.