FOOD SCIENCE ›› 2011, Vol. 32 ›› Issue (11): 239-242.doi: 10.7506/spkx1002-6630-201111049

• Bioengineering • Previous Articles     Next Articles

Purification and Characterization of Cold-adapted Neutral Protease from Enterococcus faecalis RQ15

ZHU Wei-wei,LI Yang,ZHU Wan-qin,WANG Yan-hua,JI Bao-ying,SUN Cui-huan*   

  1. Liaoning Scientific Academy of Microbiology, Chaoyang 122000, China
  • Online:2011-06-15 Published:2011-05-13

Abstract: The protease from Enterococcus faecalis RQ15 was characterized after purification with DEAE Sepharose Fast Flow and SuperdexTM 75. The molecular weight of the protease was determination by SDS-PAGE to be 32.4 kD. The optimal reaction temperature and pH of protease were 35-40 ℃ and 7.5, respectively. The protease was characterized to be a cold-adapted enzyme. It had more activity at 20-40 ℃ and a wide range of pH tolerance.The activity of the protease could be activated by Zn2+ but inhibited by Ag+, Hg2+ and EDTA-Na2 significantly. The Km and Vmax of the purified protease were 1.31 × 10-4 mol/L and 6.92×10-6 mol/(L ·s), respectively.

Key words: Enterococcus faecalis, cold-adapted acid protease, purification

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