Purification and characterization of the core-specific lectin from human serum and liver.
A lectin that displays specificity for the core region of asparagine-linked oligosaccharides (Man3GlcNAc2-Asn) was isolated from human serum and liver by affinity chromatography on mannan-Sepharose. The designation 'core-specific lectin' (CSL) is used to indicate its specificity. Selective elution of human CSL from mannan-Sepharose was accomplished with 50 mM-mannose. Two additional proteins that displayed Ca2+-dependent binding to mannan-Sepharose were eluted by mannose 6-phosphate or beta-glycerophosphate but not by mannose. The latter proteins were identified as C-reactive protein and serum amyloid protein. Human CSL isolated from liver was indistinguishable from serum CSL in its physicochemical properties, immunological properties and specificity. The N-terminal sequence of human CSL is homologous to that reported for 'mannan-binding protein C' (MBP-C) [Drickamer, Dordal & Reynolds (1986) J. Biol. Chem. 261, 6878-6887]. The amino acid composition of human CSL is similar to that of rat MBP-C, including the presence of hydroxyproline and hydroxylysine residues. Collagen-like sequences with hydroxylated proline and lysine residues appear to be present in human CSL as well as in rat CSL. The collagen-like regions of human and rat CSL may play a role in assembly of CSL subunits into complexes consisting of nine subunits that display Ca2+-dependent carbohydrate-binding activity.
Colley
K J
KJ
Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110.
Beranek
M C
MC
Baenziger
J U
JU
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000494:pharmacology; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D037102:Lectins / Q000097:blood / Q000302:isolation & purification* / Q000378:metabolism; D008099:Liver / Q000032:analysis*; D037601:Mannose-Binding Lectin; D008969:Molecular Sequence Data; D011506:Proteins / Q000494:pharmacology
D000596:Amino Acids; D002241:Carbohydrates; D037102:Lectins; D037601:Mannose-Binding Lectin; D011506:Proteins; C051631:core-specific lectin