Isolation, cDNA Cloning, Biological Properties, and Carbohydrate Binding Specificity of Sieboldin-b, a Type II Ribosome-Inactivating Protein from the Bark of Japanese Elderberry (Sambucus sieboldiana)

• Published in: Archives of biochemistry and biophysics Vol. 340; no. 2; pp. 185 - 194
• Main Authors: Rojo, Maria Angeles, Yato, Misa, Ishii-Minami, Naoko, Minami, Eiichi, Kaku, Hanae, Citores, Lucia, Girbés, Tomas, Shibuya, Naoto
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-04-1997
• Subjects: ADN; Amino Acid Sequence; carbohydrate binding; Carbohydrate Metabolism; cDNA; Cloning, Molecular; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA, Complementary - genetics; elderberry; Genes, Plant; HeLa Cells; Humans; Lectins - chemistry; Lectins - genetics; Lectins - metabolism; Molecular Sequence Data; Molecular Weight; N-Glycosyl Hydrolases - genetics; Plant Lectins; Plants - genetics; Protein Synthesis Inhibitors; Ribosome Inactivating Proteins; ribosome-inactivating protein; RNA, Plant; SAMBUCUS; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; surface plasmon resonance; cDNA; carbohydrate binding; elderberry; surface plasmon resonance; Sambucus; ribosome-inactivating protein
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1006/abbi.1997.9927

A type II ribosome-inactivating protein (RIP) was isolated from the bark tissue of Japanese elderberry (Sambucus sieboldiana) and named sieboldin-b. Sieboldin-b is a heterodimeric protein consisting of 27- and 33-kDa subunits and showed strong ribosome-inactivating activityin vitrobut did not showin vivotoxicity. The amino acid sequence of sieboldin-b deduced from the structure of the cDNA showed that both subunits of sieboldin-b are encoded on a single precursor polypeptide. Sieboldin-b has a structure homologous with the Neu5Ac(α2-6)Gal/GalNAc-specific bark lectin fromS. sieboldiana(SSA) and also typical type II RIPs such as ricin and abrin. Detailed analyses of carbohydrate binding properties of sieboldin-b revealed that sieboldin-b binds to Gal/GalNAc, similar to ricin/abrin, in spite of its highly homologous structure with SSA. The biological properties of these toxins/lectins are compared, and the possible explanation for such diversity is discussed.