Korean J Vet Res.  2015 Sep;55(3):175-179. 10.14405/kjvr.2015.55.3.175.

Characterization of proteases isolated from Kudoa septempunctata

• Shin SP
• Zenke K
• Yokoyama H

• KMID: 2049852
• DOI: http://doi.org/10.14405/kjvr.2015.55.3.175

Abstract

Proteases play important roles in parasite development and host parasite interactions. The protease of Kudoa spp. has been recognized as a key factor of severe proteolysis of fish muscle post-mortem; however, there is little information available regarding the protease of Kudoa (K.) septempunctata, which was recently identified as a cause of food poisoning in humans. The present study was conducted to isolate and characterize proteases to elucidate the type of protease contained in the parasite and determine the optimal pH for protease activity. We confirmed the cysteine protease and metalloprotease produced by K. septempunctata. While the cysteine protease showed optimal activity at pH 5 that decreased rapidly with increasing pH, the optimal activity of metalloprotease was pH 7, and it remained stable from pH 6 to pH 8. These results indicate that the pH of cysteine protease is not proper for fish muscle postmortem, and that metalloprotease can act in human intestines. Overall, the present study provides important information that improves our understanding of the role of protease physiology and the subsequent food poisoning caused by K. septempunctata.

Keyword

pH; cysteine protease; Kudoa septempunctata; metalloprotease

MeSH Terms

Cysteine Proteases
Foodborne Diseases
Host-Parasite Interactions
Humans
Hydrogen-Ion Concentration
Intestines
Parasites
Peptide Hydrolases*
Physiology
Proteolysis
Cysteine Proteases
Peptide Hydrolases