自由基氧化对大黄鱼肌原纤维蛋白交联和聚集的影响  

Effects of Radical Oxidation on the Cross-Linking Pattern of Myofibrillar Protein in Large Yellow Croaker(Pseudosciaena crocea)

作　　者：李学鹏[1] 周凯[1] 周明言[1] 王祺[1] 王金厢[1] 励建荣[1] 

机构地区：[1]渤海大学食品科学研究院辽宁省食品安全重点实验室,辽宁锦州121013

出　　处：《中国食品学报》2015年第4期13-21,共9页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31301569);"十二五"国家科技支撑计划项目(2012BAD29B06);辽宁省教育厅重点实验室基础研究项目(LZ201 4047)

摘　　要：采用不同浓度羟自由基和超氧阴离子自由基氧化体系对大黄鱼肌原纤维蛋白进行模拟氧化,研究自由基氧化对肌原纤维蛋白交联和聚集的影响。结果显示:两种自由基氧化体系均会导致大黄鱼肌原纤维蛋白羰基含量升高,同时发生不同程度的交联和聚集。在羟自由基氧化体系中,肌原纤维蛋白质粒径增大,且当H2O2浓度为10 mmol/L时达到最大粒径396.1 nm;在超氧阴离子氧化体系中,蛋白质主要发生降解作用使粒径减小,而黄嘌呤浓度为1 mmol/L时仍有部分大粒径的蛋白质生成。两种自由基体系中,总巯基的不断减少以及二硫键含量的增加表明巯基氧化形成二硫键是肌原纤维蛋白主要的交联方式之一。二聚酪氨酸含量显著增加表明氧化蛋白质的聚集也与其他共价键或非共价键生成有关。SDS-PAGE显示,两种自由基体系氧化引起的蛋白质聚集主要由二硫键交联所致,而在超氧阴离子自由基氧化体系中肌球蛋白重链受到其他交联方式的影响。羟自由基氧化体系对蛋白质交联和聚集影响比超氧阴离子自由基体系更为显著。The myofibrillar protein（MP） of large yellow croaker（Pseudosciaena crocea） was incubated in different concentrations of hydroxyl radical and superoxide anion radical oxidation systems in order to investigate the effects of protein oxidation induced by radicals on the cross-linking pattern of MP. The results showed that the carbonyl content of MP increased and extensive cross-linking and aggregation of MP was found in both oxidation systems. In the fendon oxidation system（FOS）, protein particle sizes increased, and the largest protein particle size reached to 396.1 nm when incubated in FOS of 10 mmol/L H2O2. In xanthine/xanthine oxidase system（XOS）, protein degradation led to a decrease in the MP particle size, but some macromolecular protein appeared when incubated in XOS of 1 mmol/L xanthine. Furthermore, the reduction of total sulihydryl and the increase of disulfide bond in both oxidation systems indicated that disulfide formed by the oxidation of sulihydryl was the preferred protein cross-linking pattern. Dityrosine content of MP significant increased, demonstrating that there were other covalent bonds pattern or non-covalent bond formation appeared to contribute to the cross-linking. SDS-PAGE results confirmed that protein aggregation induced by radicals was mainly caused by disulfide bond cross-linking. However, the myosin heavy chain oxidized in XOS was affected by other crosslinking patterns. Overall, the hydroxyl radical system had more obvious effects on the cross-linking and aggregation of MP than that of the superoxide anion radical system.

关 键 词：蛋白质氧化 肌原纤维蛋白 自由基 交联与聚集 

分 类 号：TS254.1[轻工技术与工程—水产品加工及贮藏工程]