Novel substrate specificity of glutathione synthesis enzymes from Streptococcus agalactiae and Clostridium acetobutylicum

Kuniki Kino, Shoko Kuratsu, Atsushi Noguchi, Masahiro Kokubo, Yuji Nakazawa, Toshinobu Arai, Makoto Yagasaki, Kohtaro Kirimura

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Glutathione (GSH) is synthesized by γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GS) in living organisms. Recently, bifunctional fusion protein, termed γ-GCS-GS catalyzing both γ-GCS and GS reactions from gram-positive firmicutes Streptococcus agalactiae, has been reported. We revealed that in the γ-GCS activity, S. agalactiae γ-GCS-GS had different substrate specificities from those of Escherichia coli γ-GCS. Furthermore, S. agalactiae γ-GCS-GS synthesized several kinds of γ-glutamyltripeptide, γ-Glu-Xaa-Gly, from free three amino acids. In Clostridium acetobutylicum, the genes encoding γ-GCS and putative GS were found to be immediately adjacent by BLAST search, and had amino acid sequence homology with S. agalactiae γ-GCS-GS, respectively. We confirmed that the proteins expressed from each gene showed γ-GCS and GS activity, respectively. C. acetobutylicum GS had broad substrate specificities and synthesized several kinds of γ-glutamyltripeptide, γ-Glu-Cys-Xaa. Whereas the substrate specificities of γ-GCS domain protein and GS domain protein of S. agalactiae γ-GCS-GS were the same as those of S. agalactiae γ-GCS-GS.

Original languageEnglish
Pages (from-to)351-359
Number of pages9
JournalBiochemical and Biophysical Research Communications
Issue number2
Publication statusPublished - 2007 Jan 12


  • Clostridium acetobutylicum
  • Glutathione
  • Glutathione synthetase
  • Streptococcus agalactiae
  • γ-Glutamylcysteine synthetase
  • γ-Glutamylpeptide

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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