PMID: 1908233

 

    Legend: Sugar

Title : Glycosylation sites identified by detection of glycosylated amino acids released from Edman degradation: the identification of Xaa- Pro-Xaa-Xaa as a motif for Thr-O-glycosylation

Abstract :

1. Here we report the use of automated Edman degradation of covalently linked glycopeptides to identify positively the sites of O- and N-glycosylation
2. The O-glycosidic linkage of carbohydrate to the hydroxy amino acids Ser and Thr is a major form of post-translational modification
3. However, unlike Asn-linked glycosylation, which is identified by the consensus sequence Asn-Xaa-Thr/Ser, no simple motif conferring O-linkage to Thr and Ser has been described
4. After sequencing glycopeptides derived from two cell surface glycoproteins , a Thr-O-glycosylation motif of Xaa- Pro-Xaa-Xaa, where at least one Xaa = Thr (Sac), has been defined
5. This motif predicts the site(s) of Pro- associated Thr-O-glycosylation in O-glycosylated proteins , although it is clear that there are also other forms of Thr-O-glycosylation not associated with Pro