Identification of cysteine protease inhibitors that belong to cystatin family 1 in the cellular slime mold dictyostelium discoideum

Medhat S. El-Halawany, Susumu Ohkouchi, Hideki Shibata, Kiyotaka Hitomi, Masatoshi Maki

Research output: Contribution to journalArticle

5 Scopus citations


Family 1 cystatins are cytosolic inhibitors of cysteine proteases, and they are conserved in higher eukaryotes. We characterized two newly identified family 1 cystatins of the cellular slime mold Dictyostelium discoideum, cystatin A1 and A2. Their recombinant proteins showed specific inhibitory activity against papain and cathepsin B, respectively. Using specific polyclonal antibodies, we found that cystatin A1 is stably expressed throughout the life cycle of Dictyostelium, whereas cystatin A2 expression is up-regulated during the course of development.

Original languageEnglish (US)
Pages (from-to)547-550
Number of pages4
JournalBiological Chemistry
Issue number6
Publication statusPublished - Jun 1 2004
Externally publishedYes



  • Cathepsin B
  • Development
  • Inhibition specificity
  • Papain
  • Protein expression profile

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Clinical Biochemistry

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