Formation of homogeneous carbohydrate-lectin cross-linked precipitates from mixtures of D-galactose/N-acetyl-D-galactosamine-specific lectins and multiantennary galactosyl carbohydrates.
Quantitative precipitation studies have shown that the Man/Glc-specific lectin concanavalin A (ConA) forms homogeneous (homopolymeric) cross-linked precipitates with individual asparagine-linked oligomannose and bisected hybrid-type glycopeptides in the presence of binary mixtures of the carbohydrates [Bhattacharyya, L., Khan, M. I. & Brewer, C. F. (1988) Biochemistry 27, 8762-8767]. The results indicate that the ConA-glycopeptide precipitates are highly organized cross-linked lattices that are unique for each carbohydrate. Using similar techniques, the present study shows that the Gal-specific lectins from Erythrina indica and Ricinus communis (agglutinin I) form homogeneous cross-linked complexes with individual carbohydrates in binary mixtures of triantennary and tetraantennary complex-type oligosaccharides with terminal Gal residues. Conversely, binary mixtures of Gal/GalNAc-specific lectins from E. indica, Erythrina cristagalli, Erythrina flabelliformis, R. communis, soybean (Glycine max), and Wistaria floribunda (tetramer) in the presence of a naturally occurring or synthetic branched-chain oligosaccharide with terminal GalNAc or Gal residues provide evidence for the formation of separate cross-linked lattices between each lectin and the carbohydrate. The present results therefore demonstrate the formation of homogeneous lectin-carbohydrate cross-linked lattices in (a) a mixture of branched-chain complex-type oligosaccharides in the presence of a specific Gal/GalNAc-binding lectin, and (b) a mixture of lectins with similar physicochemical and carbohydrate binding properties in the presence of an oligosaccharide. These findings show that lectin-carbohydrate cross-linking interactions provide a high degree of specificity which may be relevant to their biological functions as receptors.
Bhattacharyya
L
L
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461.
Brewer
C F
CF
D000116:Acetylgalactosamine; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003432:Cross-Linking Reagents; D005690:Galactose; D006385:Hemagglutination Inhibition Tests; D006386:Hemagglutination Tests; D037102:Lectins; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
D003432:Cross-Linking Reagents; D037102:Lectins; D009844:Oligosaccharides; D000116:Acetylgalactosamine; D005690:Galactose