4-O-acetyl-N-acetylneuraminic acid in the N-linked carbohydrate structures of equine and guinea pig alpha 2-macroglobulins, potent inhibitors of influenza virus infection
To investigate the molecular basis of the differential ability of human, equine, and guinea pig alpha 2-macroglobulins to inhibit hemagglutination and infectivity of a human influenza virus, A/Memphis/102/72 (H3N2), the structures of oligosaccharides released from the three glycoproteins by hydrazin...
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Published in | The Journal of biological chemistry Vol. 264; no. 17; pp. 9842 - 9849 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
15.06.1989
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Subjects | |
Online Access | Get full text |
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Summary: | To investigate the molecular basis of the differential ability of human, equine, and guinea pig alpha 2-macroglobulins to
inhibit hemagglutination and infectivity of a human influenza virus, A/Memphis/102/72 (H3N2), the structures of oligosaccharides
released from the three glycoproteins by hydrazinolysis were analyzed comparatively. Approximately seven to eight sugar chains
were released from each subunit of two potent inhibitors (equine and guinea pig alpha 2-macroglobulins) and a weak inhibitor
(human alpha 2-macroglobulin). More than 70% of the oligosaccharides contained sialic acids in all three cases. Structural
analysis of these sialo-oligosaccharides revealed that all of the three glycoproteins contain biantennary oligosaccharides
with one and two sialic acids as major sugar chains (70-80% of total sugar chains). Four percent of the biantennary oligosaccharides
from equine sample, 10% of those from guinea pig, and 24% of those from human contain a fucosylated trimannosyl core. No triantennary
oligosaccharide was detected in equine alpha 2-macroglobulin. However, human and guinea pig alpha 2-macroglobulins contain
both fucosylated and nonfucosylated triantennary oligosaccharides. All sialic acid residues occur as the Sia alpha 2---6Gal
group. The one unique feature of the carbohydrate groups of equine and guinea pig alpha 2-macroglobulins was the presence
of 4-O-Ac-Neu5Ac as 30-50% of the total sialic acids, while human alpha 2-macroglobulin contained only Neu 5Ac. However, 4-O-Ac-Neu5Ac
is not responsible for the potent inhibition of influenza virus infection and hemagglutination as will be described in the
accompanying paper. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9258 1083-351X |