Biotech Values

[DewDiligence]

On the variation of glycosylation in human plasma derived antithrombin

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_...

[At GTCB’s annual meeting in May, I chatted with Harry Meade, GTCB’s head of R&D, about glycosylation and AT isoforms. According to Dr. Meade, this is not an area for concern. In fact, there is some evidence that ATryn may work slightly better than plasma-derived AT due to the slightly different proportion of isoforms resulting in greater binding affinity to heparin.]

>>
J Chromatogr A. 2005 Jul 1;1080(1):15-21.

Demelbauer UM, Plematl A, Josic D, Allmaier G, Rizzi A.

Institute of Analytical Chemistry, University of Vienna, A-1090 Vienna, Austria.

The paper presents data on the primary structure of the glycan variants present in human antithrombin (AT) isoforms obtained from a plasma pool. The analysis is conducted on the level of glycopeptides gained by tryptic digestion. The glycopeptides were pre-separated by lectin-affinity chromatography and analyzed by means of electrospray ionization-tandem mass spectrometry involving collision-induced dissociation. Variations of the canonical biantennary complex-type structure were present with relative abundances of about 1-5% and most of them were found site-specifically. Core fucosylation was observed at one single glycopeptide only (peptide containing N155), triantennary glycan structures with two glycopeptides (containing N155 and N135). Deficiency of one terminal sialic acid was observed as not site-specific. Fucosylation was not yet reported to be present in human AT from plasma, opposite to recombinant human AT from baby hamster kidney cells, which was reported as fully core fucosylated.

In total, the variability in the carbohydrate structure of plasma derived AT appears as being quite limited. This might be of significance in the context of the reported correlation between glycosylation and physiological activity.

PMID: 16013610 [PubMed - in process]
<<