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).
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.
Rojo
Maria Angeles
MA
Department of Biochemistry, National Institute of Agrobiological Resources, University of Tsukuba, Tsukuba, Ibaraki 305.
Kaku
Hanae
H
Ishii-Minami
Naoko
N
Minami
Eiichi
E
Yato
Misa
M
Hisajima
Shigeru
S
Yamaguchi
Takeshi
T
Shibuya
Naoto
N
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
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