Dioscorin, the major tuber storage protein of yam (Dioscorea batatas Decne) with carbonic anhydrase and trypsin inhibitor activities

Wen Chi Hou, Jih Shiou Liu, Hsien Jung Chen, Tzeng Err Chen, Chung Fang Chang, Yaw Huei Lin

Research output: Contribution to journalArticle

76 Citations (Scopus)

Abstract

Dioscorin, the tuber storage protein of yam (Dioscorea batatas Decne), was purified successively by ammonium sulfate fractionation, DE-52 ion exchange chromatography, and Sephadex G-75 column. Two protein bands (82 and 28 kDa) were found under nonreducing conditions after SDS-PAGE; but only one band (32 kDa) was detected under reducing conditions. The first 21 amino acids in the N-terminal region of the 28 kDa form were VEDEFSYIEGNPNGPENWGNL, which was highly homologous to deductive sequence of dioscorin from cDNA of another yam species (Dioscorea cayenensis Lam) reported by Conlan et al. (Plant Mol. Biol. 1995, 28, 369-380). Hewett-Emmett and Tashian (Mol. Phylogenet. Evol. 1996, 5, 50-77) mentioned that, according to DNA alignments, dioscorin from yam (D. cayenensis) was α-carbonic anhydrase (α- CA) related. In this report, we found that the purified dioscorin showed both CA dehydration activity using sodium bicarbonate as a substrate and CA activity staining after SDS-PAGE. A polyclonal antibody, which was raised against trypsin inhibitor (TI), a storage protein of sweet potato (Ipomoea batatas [L.] Lam var. Tainong 57), cross-reacted with dioscorin, which also showed TI activity determined by both activity staining after SDS-PAGE and trypsin inhibition determination.

Original languageEnglish
Pages (from-to)2168-2172
Number of pages5
JournalJournal of Agricultural and Food Chemistry
Volume47
Issue number5
DOIs
Publication statusPublished - May 1999
Externally publishedYes

    Fingerprint

Keywords

  • Carbonic anhydrase
  • Dioscorea batatas Decne
  • Dioscorin
  • Storage proteins
  • Trypsin inhibitor
  • Yam

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Food Science
  • Chemistry (miscellaneous)

Cite this