A. Pisano et al., CHARACTERIZATION OF O-LINKED GLYCOSYLATION MOTIFS IN THE GLYCOPEPTIDEDOMAIN OF BOVINE KAPPA-CASEIN, Glycobiology, 4(6), 1994, pp. 837-844
kappa-Casein is the major glycoprotein in bovine milk, It has a protei
nase-sensitive (chymosin) site which cleaves the glycoprotein into two
segments: N-terminal-para-kappa-casein domain and the C-terminal kapp
a-casein macroglycopeptide domain which is highly heterogeneous in oli
gosaccharide content, We have identified six sites of O-glycosylation
on the macroglycopeptide by solid-phase Edman degradation: Thr121, Thr
131, Thr133, Thr136 (A variant only), Thr142 and Thr165. No Ser residu
es are glycosylated, The glycosylation status of 15 of 17 potential O-
glycosylation sites in the B variant was accurately predicted using th
e four peptide moths previously proposed for the glycosylation of huma
n glycophorin A (Pisano, A., Redmond, J. W., Williams, K. L. and Goole
y, A. A., Glycobiology, 3, 429-435, 1993), provided one additional ass
umption is made concerning an inhibitory role for a nearby Ile.