H_2O_2氧化对肉牛血红素蛋白构象与氧化性质的影响  

Effects of H_2O_2 oxidation on conformation and oxidative properties of hemeprotein in beef

作　　者：陈皓 马国源 姬晓颖 张晴 马君义 余群力[1] CHEN Hao;MA Guoyuan;JI Xiaoying;ZHANG Qing;MA Junyi;YU Qunli(College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070,China;Qinghai Baide Investment Development Co., Ltd, Qinghai 810000,China)

机构地区：[1]甘肃农业大学食品科学与工程学院,甘肃兰州730070 [2]青海百德投资发展有限公司,青海西宁810000

出　　处：《食品与发酵工业》2019年第9期117-122,共6页Food and Fermentation Industries

基　　金：国家自然科学基金(31771905);甘肃农业大学优秀博士论文培育项目(2017003);甘肃省科技厅重点研发计划(18YF1NA075);国家肉牛牦牛产业技术体系(CARS-37)

摘　　要：该研究采用36月龄公牛背最长肌,提取血红素蛋白,并对蛋白质溶液建立H_2O_2氧化体系模拟体内氧化条件。采用激光拉曼光谱、傅里叶变换红外光谱分析H_2O_2处理对血红素蛋白的构象的影响,并考察其对二硫键、NO自由基和超氧化物歧化酶(superoxide dismutase,SOD)等氧化性质的影响。结果表明,血红素蛋白在使用H_2O_2氧化后,血红素卟啉环结构整体扩张,Fe原子接近卟啉环平面,α-螺旋含量下降7. 37%、β-折叠含量上升8. 77%、β-转角含量上升12. 03%、无规则卷曲含量下降9. 66%。二硫键浓度上升31. 791μmol/g,NO自由基浓度增加7. 078μmol/g,SOD活性略微上升后显著降低至11. 642 U/mg。得出H_2O_2氧化使血红素蛋白的卟啉环结构整体扩张,二级结构发生改变,进而使得二硫键含量升高,NO自由基含量上升,SOD含量降低。In order to study the changes in the structure and oxidative properties of hemeprotein before and after oxidation, longissimus dorsi muscle from a 36-month-old ox was used to extract hemeprotein. The effects of H2O2 treatment on its conformation were analyzed by laser raman spectroscopy and fourier transform infrared spectroscopy (FTIR). Besides, effects of H 2O 2 on disulfide bonds, NO free radicals, and oxidative properties of superoxide dismutase (SOD) were investigated. The results showed that after oxidizing the hemeprotein with H 2O 2, the heme porphyrin ring structure was completely expanded. Moreover, the Fe atom was close to the surface of porphyrin ring, the contents of α-helix and random coil decreased 7.37% and 9.66%, respectively. The contents of β-fold and β-rotation angle increased 8.77% and 12.03%, respectively. Furthermore, the contents of disulfide bonds increased 31.791 μmol/g, and NO free radicals increased 7.078 μmol/g. The SOD activity decreased significantly to 11.642 U/mg after a slight increase. The results revealed that H 2O 2 oxidation resulted in a complete expansion of porphyrin ring structure in hemeprotein as well as changes in the secondary structure. Consequently, the contents of disulfide bonds and NO free radicals in hemeprotein increased, while the amount of SOD decreased.

关 键 词：血红素蛋白 卟啉环结构 二级结构 氧化性质 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]