The identification of threonine-95 as the major site of glycosylation in normal human myelin basic protein.

The enzymic transfer of N-acetylgalactosamine to myelin basic protein and that to peptides derived from basic protein were compared. Basic protein treated with pepsin and trypsin before glycosylation resulted in decreases of 7% and 23% in the amount of N-acetylgalactosamine transferred to the peptides respectively. However, digestion of basic protein had little effect on the sites glycosylated. It was found that Thr-95 was the major site for glycosylation in both the intact human basic protein and in the tryptic peptides.