Characterization and molecular cloning of Sambucus nigra agglutinin V (nigrin b), a GalNAc-specific type-2 ribosome-inactivating protein from the bark of elderberry (Sambucus nigra).
The molecular structure of the Sambucus nigra agglutinin V (SNAV), which has been described previously as a type-2 ribosome-inactivating protein called nigrin b, has been studied in detail by analysis of the purified protein combined with cDNA cloning and molecular modelling. Native SNAV is a dimer of two [A-s-s-B] pairs. Hapten inhibition assays indicated that GalNAc is a 20-fold more potent inhibitor of SNAV than Gal. A cDNA clone encoding SNAV was isolated from a cDNA library constructed with mRNA from the bark. Sequence analysis of this cDNA revealed a striking similarity to the recently cloned NeuAc alpha-2,6-gal/GalNAc-specific S. nigra bark agglutinin I (SNAI) and to the previously sequenced type-2 ribosome-inactivating proteins from Ricinus communis and Abrus precatorius. In addition, molecular modelling of SNAV further suggested that its structure closely resembles that of ricin. The N-terminal sequence of the B chain of SNAV also shows a marked similarity with the polypeptide of the previously described GalNAc-specific s. nigra bark agglutinin II (SNAII), which unlike SNAV and SNAI has no ribosome-inactivating activity. It appears, therefore, that elderberry bark contains at least two different type-2 ribosome-inactivating proteins and a lectin built up of subunits which are closely related to the B chain of SNAV.
Van Damme
E J
EJ
Laboratory for Phytopathology and Plant Protection, Katholieke Universiteit Leuven, Belgium.
Barre
A
A
Rougé
P
P
Van Leuven
F
F
Peumans
W J
WJ
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D006384:Hemagglutination / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D037102:Lectins / Q000737:chemistry* / Q000235:genetics* / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases; D010802:Phylogeny; D037121:Plant Lectins; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics* / Q000494:pharmacology; D011487:Protein Conformation; D011817:Rabbits; D012156:Reticulocytes / Q000187:drug effects; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D017386:Sequence Homology, Amino Acid; D009626:Terminology as Topic; D014197:Trees / Q000737:chemistry / Q000235:genetics
D018076:DNA, Complementary; D018744:DNA, Plant; D037102:Lectins; D037121:Plant Lectins; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C050600:Sambucus nigra lectins; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins