FOOD SCIENCE ›› 2013, Vol. 34 ›› Issue (9): 80-84.doi: 10.7506/spkx1002-6630-201309018

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Fast Separation and Purification of Superoxide Dismutase Using Magnetic Nanoparticles

YANG Lin1,SUN Shu-guo2,LUO Zhang1,*   

  1. 1. College of Food Science, Tibet Agricultural and Animal Husbandry College, Linzhi 860000, China;
    2. National Engineering Laboratory for Rice and Byproduct Process, Faculty of Food Science and Engineering,
    Center South University of Forestry and Technology, Changsha 410004, China
  • Received:2012-11-14 Revised:2013-04-11 Online:2013-05-15 Published:2013-05-07
  • Contact: Zhang LUO E-mail:luozhangvip@163.com

Abstract:

The magnetic nanoparticles used to quickly separate and purify superoxide dismutase (SOD) from yak blood was
evaluated and a kinetic model of SOD adsorption was established in our experiments. The effects of pH of binding buffer (sodium
phosphate buffer) and the dissociation buffer (sodium acetate buffer), NaCl concentration and adsorption time on the specific
activity and recovery of SOD were investigated to determine the optimal conditions for separation and purification of the
enzyme. The specific activity of SOD revealed an initial increase and a final decrease with the increase of pH, but the enzyme
recovery revealed a stable increase, suggesting that optimal pH of binding buffer was 7.5. The specific activity and recovery of
SOD exhibited an initial increase and following decrease with the increase of NaCl concentration. Meanwhile, the maximum
SOD adsorption was observed in the presence of 0.5 mol/L NaCl. When pH of dissociation buffer was increased from 4.0 to
5.5, the specific activity of SOD revealed an improvement, but the recovery of enzyme revealed a reduction. So the optimal
pH of dissociation buffer was determined to be 5.0. The experimental results also showed that under the optimal adsorption
conditions, the optimal static adsorption time was 2 h. As the concentration of crude enzyme extract was increased, SOD adsorption could be
expressed by Langmuir adsorption model. The specific activity of SOD was always maintained at a high level (3000—3250 U/mg), which
showed that the best separation selectivity for SOD can be achieved by using magnetic nanoparticles.

Key words: yak blood, superoxide dismutase, specific activity, adsorption kinetics

CLC Number: