肌红蛋白血红素辅基氧化修饰对肌球蛋白结构性质的影响  

Influence of Oxidative Modification of Hemin Prosthetic Group of Myoglobin on the Structure and Properties of Myosin

作　　者：朱宏星 王道营[2] 徐为民 孙冲[2] 葛庆丰[1] 高田毅[2] 黄杨 ZHU Hongxing;WANG Daoying;XU Weimin;SUN Chong;GE Qingfeng;GAO Tianyi;HUANG Yang(College of Food Science and Engineering,Yangzhou University,Yangzhou 225127,China;Institute of Agri-products Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China)

机构地区：[1]扬州大学食品科学与工程学院,江苏扬州225127 [2]江苏省农业科学院农产品加工研究所,江苏南京210014

出　　处：《肉类研究》2020年第11期1-8,共8页Meat Research

基　　金：国家自然科学基金面上项目(31973137);江苏省食品质量安全重点实验室自主研究项目(2019JG001)。

摘　　要：以肌球蛋白为对象,研究血红素辅基氧化修饰对肌球蛋白羰基、巯基、表面疏水性、溶解度、ATPase活力、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、内源荧光、二级结构的影响,并对血红素辅基氧化修饰肌球蛋白进行分子动力学模拟。结果表明:在低浓度血红素辅基氧化下,肌球蛋白的表面疏水性显著降低(P<0.05);高浓度血红素辅基氧化下,肌球蛋白表面疏水性显著增加(P<0.05),溶解度显著降低(P<0.05);血红素辅基处理后,肌球蛋白总巯基和活性巯基含量显著下降(P<0.05),Ca2+-ATP酶活力显著降低(P<0.05);肌球蛋白荧光强度降低、峰值蓝移及α-螺旋相对含量下降,表明血红素辅基对肌球蛋白的构象产生影响;分子动力学模拟结果证实血红素辅基能与肌球蛋白结合,但高度氧化状态下不利于维持肌球蛋白结构的稳定。综上,血红素辅基可以通过氧化修饰肌球蛋白,引起肌球蛋白结构变化,进而对肉品品质造成影响。In this paper, the influence of oxidative modification of the hemin prosthetic group of myoglobin on the carbonyl and sulfhydryl groups, surface hydrophobicity, solubility, ATPase activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) profile, endogenous fluorescence, and secondary structure of myosin. Meanwhile, molecular dynamics simulation was performed on myoglobin with oxidative modification of its hemin prosthetic group. The results showed that the surface hydrophobicity of myosin significantly decreased(P < 0.05) when the hemin prosthetic group was oxidized at low concentrations, but significantly increased(P < 0.05) at high concentrations, together with a significant reduction in the solubility(P < 0.05). Hemin prosthetic group modification significantly decreased the contents of total and reactive sulfhydryl groups and Ca2+-ATPase activity of myosin(P < 0.05). In addition, this treatment reduced the fluorescence intensity of myosin accompanied by a spectral blue shift and the proportion of α-helix indicating conformational changes in myosin. Molecular dynamics simulation revealed that the hemin prosthetic group could bind to myosin. However, its oxidation at high concentrations was detrimental to maintaining the stability of myosin. In a word, oxidative modification of the hemin prosthetic group could cause structural changes in myosin and consequently affect meat quality.

关 键 词：肌红蛋白血红素辅基 肌球蛋白 蛋白氧化 分子动力学模拟 肉品品质 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]