Purification and characterization of a new mannose-specific lectin from Sternbergia lutea bulbs.
A new mannose-binding lectin was isolated from Sternbergia lutea bulbs by affinity chromatography on an alpha(1-2)mannobiose-Synsorb column and purified further by gel filtration. This lectin (S. lutea agglutinin; SLA) appeared homogeneous by native-gel electrophoresis at pH 4.3, gel filtration chromatography on a Sephadex G-75 column, and SDS-polyacrylamide gel electrophoresis, These data indicate that SLA is a dimeric protein (20 kDa) composed of two identical subunits of 10 kDa which are linked by non-covalent interactions. The carbohydrate binding specificity of the lectin was investigated by quantitative precipitation and hapten inhibition assays. It is an alpha-D-mannose-specific lectin that interacts to form precipitates with various alpha-mannans, galactomannan and asialo-thyroglobulin, but not with alpha-glucans and thyroglobulin. Of the monosaccharides tested only D-mannose was a hapten inhibitor of the SLA-asialothyroglobulin precipitation system, whereas D-glucose, D-galactose and L-arabinose were not. The lectin appears to be highly specific for terminal alpha(1-3)-mannooligosaccharides. The primary structure of SLA appears to be quite similar to that of the snow drop (Galanthus nivalis) bulb lectin which is a mannose-binding lectin from the same plant family Amaryllidaceae. The N-terminal 46 amino acid sequence SLA showed 76% homology with that of GNA.
Saito
K
K
Faculty of Human Life Science, Osaka City University, Japan.
Misaki
A
A
Goldstein
I J
IJ
D000595:Amino Acid Sequence; D001665:Binding Sites; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D037222:Collectins; D019281:Dimerization; D027801:Galanthus; D037102:Lectins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D037241:Mannose-Binding Lectins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D037121:Plant Lectins; D010944:Plants / Q000737:chemistry / Q000235:genetics; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
D002352:Carrier Proteins; D037222:Collectins; D037102:Lectins; D037241:Mannose-Binding Lectins; D009844:Oligosaccharides; D037121:Plant Lectins; C063117:snowdrop lectin