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

Autor: Pirie-Shepherd, S R, Stevens, R D, Andon, N L, Enghild, J J, Pizzo, S V
Jazyk: angličtina
Rok vydání: 1997
Předmět:
Zdroj: Pirie-Shepherd, S R, Stevens, R D, Andon, N L, Enghild, J J & Pizzo, S V 1997, ' Evidence for a novel O-linked sialylated trisaccharide on Ser-248 of human plasminogen 2 ', Journal of Biological Chemistry, vol. 272, no. 11, pp. 7408-11 .
Popis: Udgivelsesdato: 1997-Mar-14 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 composition 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.
Databáze: OpenAIRE