Human L-ficolin: plasma levels, sugar specificity, and assignment of its lectin activity to the fibrinogen-like (FBG) domain.
Ficolins are characterised by the presence of collagen-like and fibrinogen-like (FBG) sequences. Human L-ficolin is synthesised in the liver and secreted into blood circulation. In previous studies, it was shown to bind to N-acetyl-D-glucosamine (GlcNAc). In the present study, its detailed sugar specificity and binding site have been investigated. It was found to bind to GlcNAc and GalNAc (N-acetyl-D-galactosamine) while showing no significant affinity for the precursor sugars. The structure in these molecules which is recognised by L.-ficolin has been deduced to include an amide (-CO-NH-) or similar group. L-Ficolin was digested with collagenase and the collagenase resistant FBG domain was shown to bind to GlcNAc. Its levels in adult and cord blood-derived human plasma were also determined and showed that adult plasma contains approximately three times more L-ficolin than that of newborn babies.
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National University Medical Institute, Clinical Research Centre, National University of Singapore, Singapore.
Lee
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Kon
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Lu
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D000328:Adult; D000818:Animals; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D002352:Carrier Proteins / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D005340:Fibrinogen / Q000737:chemistry*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D015394:Molecular Structure; D011817:Rabbits; D000097604:Ficolins
D002352:Carrier Proteins; D005340:Fibrinogen; D037102:Lectins; D000097604:Ficolins