FOOD SCIENCE ›› 2012, Vol. 33 ›› Issue (13): 100-103.doi: 10.7506/spkx1002-6630-201213020

• Basic Research • Previous Articles     Next Articles

Purification and Characterization of High Molecular Weight Caspase Inhibitor CPI-I from Silver Carp Eggs

SONGChuan,LIYan-fang,RENYang-yang,LIShu-hong   

  1. (College of Food Science, Sichuan Agricultural University, Ya, an 625014, China)
  • Online:2012-07-15 Published:2012-07-27

Abstract: In this study, crude extract concentrate from silver carp eggs was prepared and purified by Q Sepharose Fast Flow anionic chromatography and subsequent Sephacryl S-200 molecular sieve chromatography to obtain partially purified casepase inhibitor (CPI) named as CPI-I. Azocasein assay was used to determine the inhibitory activity of crude extract concentrate and CPI-I. In addition, the heat stability of CPI-I activity was evaluated using the fluorescent peptide Z-Phe-Arg-MCA as substrate. The purification factor of CPI-I relative to silver carp egg homogenate was 72, and the recovery rate was 10.25%. Based on the molecular weight standard curve obtained from Sephacryl S-200 molecular sieve chromatography and the results of reverse zymographic analysis, the molecular weight of CPI-I was preliminarily identified as 89 kD. The results of periodic acid-Schiff (PAS) staining demonstrated that CPI-I was a glycoprotein. CPI-I could inhibit cathepsin L from silver carp meat and showed remarkable heat stability.

Key words: silver carp egg, cysteine protease inhibitors, purification, characterization

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