Studies on the Oxidation of LDL Induced by Cu2+ at Different Time by Spectroscopic Method
SUN Xia1, LIU Qing-ping1, 2*, ZHENG Xue-fang1, 2, LIU Zhe1, WANG Ren-jun1, HUANG Zhen-yu1, ZHANG Fan1
1. College of Bioengineering, Dalian University, Dalian 116622, China 2. Liaoning Key Laboratory of Bio-organic Chemistry, Dalian University, Dalian 116622, China
摘要: 氧化低密度脂蛋白(oxidized low density lipoprotein,oxLDL)被认为是动脉硬化的关键致病因素。文章综合运用紫外吸收光谱、荧光光谱、同步荧光光谱及圆二色(circular dichroism, CD)光谱研究了Cu2+诱导不同时间的LDL体外氧化过程。随着氧化时间的增加,生成的丙二醛(malonaldehyde,MDA)的量逐渐增加,其相对应的430 nm处的荧光强度也随之加强,氧化过程中生成了新的氧化产物。氧化低密度脂蛋白紫外吸收增强;表征氨基酸残基信息的特征荧光强度和同步荧光强度降低;载脂蛋白B-100(apolipoprotein B-100, apoB-100)α-螺旋含量减少。实验结果表明,LDL氧化过程中Cu2+不仅诱导了氧化产物的生成,而且改变了apoB-100的构象进而导致了生色基团的微环境的变化。
关键词:氧化低密度脂蛋白;紫外光谱;荧光光谱;同步荧光光谱;圆二色(CD)光谱
Abstract:Oxidized low density lipoprotein (oxLDL) is thought to be a key proatherogenic event. The oxidation of LDL induced by Cu2+ at different time was studied by UV-Vis absorption spectra and circular dichroism (CD) spectra. It was shown that long oxidation time is accompanied by an increased MDA content and fluorescence intensity at 430 nm, which suggested new product. The intensity of UV absorption peak of LDL increased, while fluorescence and synchronous fluorescence intensities, which typified amino acids, decreased. CD data displayed that α-helical content of the protein decreased and the secondary structure changed. The results indicated that during the process of oxidation of LDL Cu2+ induced not only the product but also the change of the conformation of apoB-100.
孙霞1,刘庆平1, 2*,郑学仿1, 2,刘哲1,王仁军1,黄振宇1,张帆1. 光谱法研究Cu2+诱导的不同时间的LDL体外氧化[J]. 光谱学与光谱分析, 2009, 29(05): 1386-1389.
SUN Xia1, LIU Qing-ping1, 2*, ZHENG Xue-fang1, 2, LIU Zhe1, WANG Ren-jun1, HUANG Zhen-yu1, ZHANG Fan1 . Studies on the Oxidation of LDL Induced by Cu2+ at Different Time by Spectroscopic Method . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2009, 29(05): 1386-1389.