title: Characterization and cDNA cloning of monomeric lectins that correspond to the B-Chain of a type 2 ribosome-inactivating protein from the bark of Japanese elderberry (Sambucus sieboldiana).
abstract: Two monomeric lectins, SSA-b-3 and SSA-b-4, were purified from the bark tissue of Japanese elderberry, Sambucus sieboldiana. SDS-PAGE of the purified lectins showed the presence of single bands of 35 and 33 kDa for SSA-b-3 and SSA-b-4, respectively, irrespective of the presence of reducing agent. MS analysis as well as gel filtration of these lectins indicated that they exist mostly as monomeric lectins. Analysis of the N-terminal amino acid sequences of SSA-b-3 and SSA-b-4 yielded an identical sequence, indicating their close structural relationship. Four cDNA clones with extensive homology were obtained from the bark cDNA library and indicated to encode SSA-b-3 or SSA-b-4 from the comparison with the N-terminal sequences of these lectins. These clones were classified into two groups, three for SSA-b-3 and one for SSA-b-4, based on the predicted isoelectric points. The amino acid sequences of the encoded polypeptides were almost identical with the B-chain of a type 2 ribosome-inactivating protein from the same bark tissue, sieboldin-b, except for the absence of a small peptide containing a cystein residue, which is critical for the heteromeric dimerization with an A-subunit. Carbohydrate binding specificity and biological activity of these lectins are also reported.
authors.affiliation: Department of Biochemistry, National Institute of Agrobiological Resources, University of Tsukuba, Tsukuba, Ibaraki 305.
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Rojo
authors.forename: Hanae
authors.initials: H
authors.lastname: Kaku
authors.forename: Naoko
authors.initials: N
authors.lastname: Ishii-Minami
authors.forename: Eiichi
authors.initials: E
authors.lastname: Minami
authors.forename: Misa
authors.initials: M
authors.lastname: Yato
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hisajima
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Shibuya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001212:Asialoglycoproteins / Q000378:metabolism; D015139:Blotting, Southern; D002241:Carbohydrates / Q000494:pharmacology; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004903:Erythrocyte Aggregation / Q000502:physiology; D060748:Fetuins; D005690:Galactose / Q000378:metabolism; D006031:Glycosylation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009699:N-Glycosyl Hydrolases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D024301:Plant Bark / Q000737:chemistry / Q000235:genetics; D037121:Plant Lectins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D011817:Rabbits; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D027923:Sambucus / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012710:Serum Albumin, Bovine / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D001212:Asialoglycoproteins; D002241:Carbohydrates; D018076:DNA, Complementary; D060748:Fetuins; D037121:Plant Lectins; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C050600:Sambucus nigra lectins; D000509:alpha-Fetoproteins; C017029:asialofetuin; C026503:asialoglycophorin; C039136:bovine serum albumin-galactose (39); C105919:sieboldin b; D012710:Serum Albumin, Bovine; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins; D005690:Galactose