Bovine colostrum CMP-NeuAc:Gal beta(-->4)GlcNAc-R alpha(2-->6)-sialyltransferase (alpha 6-sialyltransferase) appears to be capable of catalysing alpha 6-sialylation of the disaccharide GalNAc beta(1-->4)GlcNAc to yield the trisaccharide NeuAc alpha(2-->6)GalNAc beta(1-->4)GlcNAc. This provides an enzymic basis for the occurrence of this sialylated structure on the N-linked glycans of a number of bovine milk glycoproteins. Competition experiments using Gal beta(1-->4)GlcNAc and GalNAc beta(-->4)GlcNAc as acceptors indicate that both substrates are recognized by a single active site on the alpha 6-sialyltransferase. Extrapolation of these results suggests that the NeuAc alpha(2-->6)GalNAc beta(1-->4)GlcNAc structural element occurring on the N-linked glycans of several human glycoproteins are similarly synthesized by the action of a Gal beta(1-->4)GlcNAc-R alpha(2-->6)-sialyltransferase.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1133160 | PMC |
| http://dx.doi.org/10.1042/bj2870311 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Redefined substrate specificity of ST6GalNAc II: a second candidate sialyl-Tn synthase.
Biochem Biophys Res Commun
May 2000
Molecular Glycobiology, Frontier Research Program, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, Japan.
The acceptor substrate specificities of ST6GalNAc I and II, which act on the synthesis of O-linked oligosaccharides, were reexamined using ovine submaxillary mucin, [Ala-Thr(GalNAc)-Ala]n polymer (n = 7-11). It has been suggested that only ST6GalNAc I can synthesize carbohydrate structures of sialyl-Tn-antigen; i.e.
View Article and Find Full Text PDFProperties of native and in vitro glycosylated forms of the glucagon-like peptide-1 receptor antagonist exendin(9-39).
Metabolism
June 1999
Unit of Protein Research, Pharmacia & Upjohn, Kalamazoo, MI, USA.
The intestinal hormone glucagon-like peptide-1-(7-36)-amide (GLP-1) has recently been implicated as a possible therapeutic agent for the management of type 2 non-insulin-dependent diabetes mellitus (NIDDM). However, a major difficulty with the delivery of peptide-based agents is their short plasma half-life, mainly due to rapid serum clearance and proteolytic degradation. Using a peptide analog of GLP-1, the GLP-1 receptor antagonist exendin(9-39), we investigated whether the conjugation of a carbohydrate structure to exendin(9-39) would generate a peptide with intact biological activity and improved survival in circulation.
View Article and Find Full Text PDFMonoclonal antibody directed against colon cancer mucin has high specificity for malignancy.
Int J Cancer
May 1993
Gastrointestinal Research Laboratory, Veterans Affairs Medical Center, San Francisco, CA 94121.
Exposure of core carbohydrate structures such as NeuAc alpha2-6GalNAc-Ser/Thr (sialosyl-Tn) in mucus glycoproteins is often associated with malignant transformation in a number of different tissues. Reagents that specifically identify such structures would be useful in the diagnosis of cancer. Monoclonal antibody JT10e has been produced against mucins from xenografts of LS174T colon cancer cells but also reacts with mucins of pancreatic cancer xenografts.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!