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)

Arch Biochem Biophys. 1997 Apr 15;340(2):185-94. doi: 10.1006/abbi.1997.9927.

Abstract

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 activity in vitro but did not show in vivo toxicity. 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(alpha 2-6)Gal/GalNAc-specific bark lectin from S. 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carbohydrate Metabolism
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • 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*
  • RNA, Plant
  • Ribosome Inactivating Proteins

Substances

  • DNA, Complementary
  • Lectins
  • Plant Lectins
  • Protein Synthesis Inhibitors
  • RNA, Plant
  • sieboldin b
  • N-Glycosyl Hydrolases
  • Ribosome Inactivating Proteins