Glyco

Title : Evidence for a novel O-linked sialylated trisaccharide on Ser-248 of human plasminogen 2

Abstract :

Human plasminogen , the inactive precursor of plasmin , exists in two major glycoforms
Plasminogen 1 contains an N-linked oligosaccharide at Asn-289 and an O-linked oligosaccharide at Thr-345
Plasminogen 2 is known to contain only an O-linked oligosaccharide at Thr-345
However, plasminogen 2 displays a further well documented microheterogeneity dependent on the N-acetylneuraminic acid content, which has functional consequences with regard to activation of plasminogen
The proposed structure and number of known oligosaccharide linkages in plasminogen 2 is insufficient to account for this microheterogeneity
In the present study, a combination of trypsin digestion, lectin affinity chromatography, Edman degradation amino acid sequence analysis, carbohydrate com position analysis, and mass spectrometry revealed the existence of a novel site for O-linked glycosylation on plasminogen 2 at Ser-248
Direct evidence for the structure of the carbohydrate was obtained from a combination of lectin affinity chromatography, desialylation experiments, and mass spectrometry analysis
These findings provide a structural basis for some of the observed microheterogeneity, and have implications with regard to the known functional consequences of the extent of sialylation of plasminogen

Output (sent_index, trigger, protein, sugar, site):

Output(Part-Of) (sent_index, protein, site):

*Output_Site_Fusion* (sent_index, protein, sugar, site):