Amino acid sequence and oligosaccharide attachment sites of the glycosylated domain of dog erythrocyte glycophorin.

Glycophorin was prepared from dog erythrocyte membranes by extraction with lithium diiodosalicylate and partition in aqueous phenol. Tryptic and chymotryptic treatments of the glycophorin produced two major glycopeptides labeled T1 and CH1, respectively. The glycopeptides were isolated by gel chromatography followed by ion-exchange chromatography, and subjected to amino acid sequence analysis. Both glycopeptides represented the amino-terminal domain of the major dog glycophorin; T1 of 52 residues and CH1 of 43 residues. The amino-terminal sequence of dog glycophorin does not have significant homology with those of human, horse or porcine glycophorins. This result is in good agreement with our previous proposal that there is no homology in the sequence of the amino-terminal glycosylated domain of glycophorin.