摘要
【目的】探究乙二胺四乙酸钠(EDTA)对猪肉12-脂肪氧合酶(12-LOX)构象和酶活力的影响,为猪肉加工贮藏过程中控制12-LOX活性提供参考依据。【方法】采用EDTA处理猪肉12-LOX,测定其酶活力,并分析EDTA对猪肉12-LOX的储藏稳定性、热稳定性、催化亚油酸反应、荧光光谱和圆二色谱(Circular dichrosim spectra,CD)的影响。【结果】添加EDTA可抑制猪肉12-LOX的酶活力,随EDTA浓度的增加,抑制作用逐渐增强,当EDTA浓度为10.0 mmol/L时,猪肉12-LOX活力约下降60%。EDTA能提高猪肉12-LOX的热稳定性和贮藏稳定性,使其比正常条件下保持较高酶活力。随着EDTA浓度的增加,猪肉12-LOX分子内部的α-螺旋和β-折叠含量降低,引起其二级结构发生明显变化;猪肉12-LOX的荧光强度不断减弱,EDTA浓度为20.0 mmol/L时,酶的内源荧光发射峰强度下降13%,但最大发射峰(λmax)的位置未发生变化。【结论】EDTA能引起猪肉12-LOX的构象变化进而抑制其酶活力。
【Objective】To investigate the effects of sodium ethylene diamite tetracetate(EDTA)on the conformation and enzyme activity of porcine 12-lipoxygenase(12-LOX),and provide reference for controlling 12-LOX activity during pork processing and storage.【Method】Porcine 12-LOX was treated with EDTA to determine the enzyme activity of porcine 12-LOX,and the storage stability,thermal stability,catalytic linoleic acid reaction,fluorescence spectroscopy and circular dichroism spectra(CD)of EDTA effects on porcine 12-LOX were analyzed.【Result】The results showed that EDTA inhibited the activity of porcine 12-LOX and the inhibitory effect increased with the increasing of EDTA concentration. When the concentration of EDTA was 10.0 mmol/L,the activity of porcine 12-LOX decreased by 60% approximately. The addition of EDTA could increase the thermal stability and storage stability of porcine 12-LOX and make porcine 12-LOX retain enzyme activity for a longer time than normal conditions. As the concentration of EDTA increased, the content of α-helix and β-sheet inside the porcine 12-LOX molecule decreased,causing obvious change in its secondary structure and the fluorescence intensity of porcine 12-LOX was continuously weakened. When the concentration of EDTA was 20.0 mmol/L,the intensity of the endogenous fluorescence emission peak of the enzyme decreased by 13%, but the position of the maximum emission peak(λmax)did not change.【Conclusion】Collectively,this study indicates that EDTA can cause conformational change of porcine 12-LOX and result in the activity change of porcine 12-LOX,which may providereference for the control of LOX activity during meat processing and storage.
作者
王晶晶
张新笑
卞欢
耿志明
李鹏鹏
王道营
徐为民
WANG Jing-jing;ZHANG Xin-xiao;BIAN Huan;GENG Zhi-ming;LI Peng-peng;WANG Dao-ying;XU Wei-min(Institute of Agro-product Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;Key Laboratory of Meat Processing and Quality Control,Ministry of Education,Nanjing Agricultural University,Nanjing 210095,China;Jiangsu Collaborative Innovation Center of Meat Production and Processing,Quality and Safety Control,Nanjing 210095,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2019年第9期2052-2057,共6页
Journal of Southern Agriculture
基金
国家青年科学基金项目（31701532）
江苏省自然科学基金面上项目（BK20171324）
江苏省农业科学院自主研究项目（jg201702）
