经自由基氧化的乳清蛋白对碱性蛋白酶水解敏感性的研究

Study on proteolysis susceptibility of Alcalase to the oxidized whey protein by a free radical-generating system

研究了在羟基自由基氧化体系中,不同的H2O2浓度、FeCl3浓度对活性巯基含量的影响,以表明蛋白质的氧化程度,进一步对氧化的乳清蛋白进行酶水解,研究不同氧化条件下获得的乳清蛋白对碱性蛋白酶水解的敏感性,以及水解蛋白的三氯乙酸可溶性氮的变化。结果表明:氧化会引起乳清蛋白活性巯基的降低(P<0.05),经过氧化的蛋白明显更易于发生水解作用,无论是水解度还是TCA可溶性氮都有明显的增加(P<0.05)。表明氧化促进了蛋白酶的水解,提高了蛋白质对水解酶的敏感性,这意味着氧化后的蛋白可能更容易在体内被分解。

The changes of active sulfhydryts in different concentrations of H2O2 or FeCl3 were investigate,the effect of protein oxidation on proteolysis susceptibility of Alcalase in different oxidative conditions, and the changes of 12% TCA-N（Trichloroacetic acid nitrogen） solubility.The results showed that protein oxidation could significantly decrease the active sulfhydryls content（ P 〈0.05） in different oxidative environment.The oxidized whey protein was more easily hydrolyzed by Alcalase.The protein oxidation could significantly increase the degree of hydrolysis（DH） and 12% TCA-N solubility （P 〈 0.05）. It revealed proteolysis susceptibility was improved by protein oxidation, making protein hydrolysis more easily.It means that whey protein became more easily digestion after oxidation.