A novel extracellular protease of Vibrio mimicus that mediates maturation of an endogenous hemolysin

Tamaki Mizuno, Ayako Nanko, Yoko Maehara, Sumio Shinoda, Shin-ichi Miyoshi

Research output: Contribution to journalArticle


Vibrio mimicus, a human pathogen that causes gastroenteritis, produces an enterotoxic hemolysin as a virulence factor. The hemolysin is secreted extracellularly as an inactive protoxin and converted to a mature toxin through removal of the N-terminal propeptide, which comprises 151 amino acid residues. In this study, a novel protease having the trypsin-like substrate specificity was purified from the bacterial culture supernatant. The N-terminal amino acid sequence of the purified protein was identical with putative trypsin VMD27150 of V. mimicus strain VM573. The purified protease was found to cause maturation of the protoxin by cleavage of the Arg151-Ser152 bond. Deletion of the protease gene resulted in increased amounts of the protoxin in the culture supernatant. In addition, expression of the hemolysin and protease genes was detected during the logarithmic growth phase. These findings indicate that the protease purified may mediate maturation of the hemolysin.

Original languageEnglish
Pages (from-to)503-512
Number of pages10
JournalMicrobiology and Immunology
Issue number9
Publication statusPublished - 2014



  • Hemolysin
  • Maturation
  • Protease
  • Vibrio mimicus

ASJC Scopus subject areas

  • Immunology
  • Microbiology
  • Virology
  • Medicine(all)

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