Khattari Ziad
Physics Department, Faculty of Science, Hashemite University, Zarqa, Jordan.
J Biol Phys. 2017 Sep;43(3):381-395. doi: 10.1007/s10867-017-9458-3. Epub 2017 Jun 24.
The secondary structure of apolipoprotein B-100 is studied within the bulk phase and at the air/water interface. In these "in viro" experiments, infrared reflection absorption spectroscopy (IRRAS) study was performed at the air/water interface while circular dichroism (CD) was conducted in the bulk phase. In the bulk phase, the conformational structure containing a significant amount of β-structure, whereas varying amount of α-helix, unordered structures, and β-sheet were observed at the air/water interface depending on the low-density lipoprotein (LDL) film interfacial pressure. The present IRRAS results demonstrate the importance of interfacial pressure-induced structural conformations on the apoB-100. A correlation between the secondary structure of the apoB-100 protein and the monomolecular film elasticity at the air/water interface was also established. The orientation of apoB-100 with respect to the LDL film-normal was found to depend on the interfacial pressure exhibited by the monomolecular film. These results may shed light on LDL's pivotal role in the progression of atherosclerotic coronary artery disease as demonstrated previously by clinical trials.
载脂蛋白B - 100的二级结构在本体相和空气/水界面进行了研究。在这些“体外”实验中，在空气/水界面进行了红外反射吸收光谱（IRRAS）研究，而在本体相中进行了圆二色性（CD）研究。在本体相中，构象结构含有大量的β - 结构，而在空气/水界面观察到不同数量的α - 螺旋、无序结构和β - 折叠，这取决于低密度脂蛋白（LDL）膜的界面压力。目前的IRRAS结果证明了界面压力诱导的结构构象对载脂蛋白B - 100的重要性。还建立了载脂蛋白B - 100蛋白的二级结构与空气/水界面单分子膜弹性之间的相关性。发现载脂蛋白B - 100相对于LDL膜法线的取向取决于单分子膜所呈现的界面压力。这些结果可能有助于阐明低密度脂蛋白在动脉粥样硬化性冠状动脉疾病进展中的关键作用，正如先前临床试验所证明的那样。
