O-glycosylated

Jentoft, N., 1990. Wliy are proteins O-glycosylated Trends in Biochemical Sciences 155 291-294. 

The diamonds in Fig. 1 represent the point of O-glycosylation by tetrasac-charide 1. Asn-26 indicates the point of N-glycosylation by the complex oligosaccharide 2. 

PGE was isolated as desribed in Material and Methods. SDS-PAGE electrophoresis of purified protein showed a single band migrating at approximately 60 kDa. This observation is not in the agreement with the calculated molecular weight of 35 584. However a similar effect has been observed previously in case of PGI and PGC. Apart of the N-glycosylation which plays role in all PGs (Fig. 3), O-glycosylation may also be present as indicated by the band size shift after a treatment of PGE with O.IM NaOH (data not shown). 

IV. Structural Analysis of Glycopeptides and Glycoproteins Containing O-Glycosyl Linkages... 

Now that the general considerations concerning the 13C-n.m.r.-spec-tral data for O-glycosylated model compounds have been discussed, attention may be focused on some specific cases. Table IV gives the 13C-n.m.r.-spectral data for L-serine that has been glycosylated with various carbohydrates, such as a- and / -d-G1c, a- and /9-D-Gal, a- and / -d-Xyl, a-D-Man, and a-D-GalNAc. As mentioned earlier, the specific resonance-assignments to amino acid carbon atoms were based on chemical... 

As mentioned in the Introduction, a variety of unusual carbohydrate -protein linkages is found in Nature. These may be placed in several categories (i) carbohydrates O-glycosylated to jff-hydroxy amino acids (ii) carbohydrates S-glycosylated to cysteine (Hi) carbohydrates N-gly-cosylated to the N-terminal amino group of the protein or (iv) in some... 

---