Purification and partial characterization of a novel lectin from elder (Sambucus nigra L.) fruit.
A previously unknown haemagglutinin, named Sambucus nigra agglutinin-III (SNA-III), has been purified from the fruit of the elder (Sambucus nigra). Whereas elder bark agglutinin I (SNA-I) is highly specific for terminal alpha 2,6-linked sialic acid residues, SNA-III displays a high affinity for oligosaccharides containing exposed N-acetylgalactosamine and galactose residues. Different N-terminal sequences and the amino acid composition distinguish the fruit lectin from elder bark agglutinin II (SNA-II), which shows a similar carbohydrate specificity. The 40-fold higher affinity of SNA-III for asialofetuin than for human asialo-alpha 1-acid glycoprotein and human asialotransferrin respectively suggests a preference for O-linked glycans. SNA-III occurs mainly as a monomeric glycoprotein, but tends to form di- and oligo-meric aggregates. This aggregation seems to mediate the multivalent interaction, leading to agglutination. SDS/PAGE revealed two major polypeptides with apparent molecular masses of 32 and 33 kDa respectively. This heterogeneity is probably a result of proteolysis in the C-terminal region. Binding to concanavalin A and susceptibility to peptide: N-glycosidase F indicated the presence of N-glycosidically linked oligosaccharides.
Mach
L
L
Zentrum für Angewandte Genetik, Universität für Bodenkultur, Vienna, Austria.
Scherf
W
W
Ammann
M
M
Poetsch
J
J
Bertsch
W
W
März
L
L
Glössl
J
J
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D050260:Carbohydrate Metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002852:Chromatography, Ion Exchange; D003208:Concanavalin A / Q000378:metabolism; D006384:Hemagglutination; D006801:Humans; D005779:Immunodiffusion; D037102:Lectins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D037121:Plant Lectins; D011817:Rabbits; D054788:Ribosome Inactivating Proteins
D000596:Amino Acids; D037102:Lectins; D037121:Plant Lectins; C050600:Sambucus nigra lectins; D003208:Concanavalin A; D054788:Ribosome Inactivating Proteins