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Purification of α-amylase from human saliva by superparamagnetic particles

Lin, Jenshinn, Lin, Yeong-Shenn, Kuo, Sho-Tin, Jiang, Chii-Ming, Wu, Ming-Chang
Journal of the science of food and agriculture 2009 v.89 no.4 pp. 574-578
humans, alpha-amylase, saliva, purification, magnetic separation, enzyme activity, molecular weight, thermal stability
BACKGROUND: Several studies of magnetic carrier technology have focused on the application of separation technology, because the magnetic support can separate the target from the reaction medium by application of a magnetic field and because the magnetic carrier can be easily recovered. In the present study, superparamagnetic iron oxide (SPIO) modified by epichlorohydrin was employed as a support whose surface could be coated with starch. The starch-coated support was used for isolating human salivary amylases.RESULTS: The results showed that the starch-SPIO support could isolate amylases from human saliva with 91.1% recovery and 3.5-fold purification to high specific activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the purifed amylase comprised two isoamylases with estimated molecular weights of 55 and 59 kDa. The activities of crude and purified amylases showed optimal pH values of 6-7 and 7 and optimal temperatures of 40 and 30 °C respectively. The thermal stability range for both crude and purified amylases was between 20 and 40 °C.CONCLUSION: The attachment of substrates to SPIO could offer a novel and efficient method for purifying enzymes either as an initial step prior to further purification or as a final step for diagnostic usage.