THE CARBOHYDRATE MOIETY OF IGM FROM ATLANTIC SALMON (SALMO-SALAR L)

The carbohydrate moiety of salmon Igh? was estimated to be about 12.5% of the total molecular weight of salmon IgM based on SDS-PAGE analysi s and less than or equal to 8.0% based on FACE analysis. The carbohydr ate moiety was restricted to the heavy chain and was all N-linked. Six different oligosaccharides were identified using the FACE oligosaccha ride profiling technique. Monosaccharide composition analysis, as well as digestion with endoglycosidase H, suggested that the oligosacchari des were mainly of the complex type rather than high mannose type. Rem oval of about 80% of the carbohydrate affected the: sensitivity of IgM to trypsin but had no effects on antigen binding or the complement fi xation ability of anti s-RBC IgM. (C) 1997 Elsevier Science Inc.