six principal glycopeptides isolated by gel chromatography and deae-sephadex a-25 chromatography in the absence or presence of borate ion were analyzed for their carbohydrate and amino acid composition , as well as amino acid sequence , and found to be of two distinct types : glycotripeptides , thr*-ser*-glu , and glycotetrapeptides , thr*-gly-pro-ser , where an asterisk indicates the amino acid residues to which either the gal beta 1 -- -- 3galnac or fuc alpha 1 -- -- 3galnac beta 1 -- -- 3gal beta 1 -- -- 4gal beta 1 -- -- 3galnac chain is attached .
C0061472
glu
C0002520
amino acid