writer：Yu Hu, Jing Jin, Haojun Liang, Xiangling Ji, Jinghua Yin, Wei Jiang
keywords：纤维蛋白原, pH, 构象, 取向, 血小板黏附, 整合素
source：期刊
specific source：Langmuir, 2016, 32(16), 4086-4094
Issue time：2016年

摘要：利用带耗散功能的石英晶体微天平（QCM-D）和双偏振干涉技术（DPI），通过改变pH值研究了纤维蛋白原（Fib）在不同表面的吸附行为，并利用DPI研究了整合素与吸附Fib的黏附，通过扫描电镜、共聚焦激光扫描显微镜和乳酸脱氢酶（LDH）释放实验对血小板黏附进行了定性和定量研究。结果表明，吸附Fib的构象和取向取决于表面性质和pH循环。对于亲水表面，pH 7.4下吸附的Fib呈αC隐藏取向，因此未观察到整合素黏附，血小板黏附数量很少；当冲洗溶液pH由7.4变为3.2再回到7.4时，吸附Fib在pH循环中发生构象转变，取向变为αC暴露，整合素更易黏附，黏附和活化的血小板增多。对于疏水表面，由于Fib与表面强相互作用，吸附的Fib更铺展和伸展，冲洗溶液pH循环后αC暴露取向保持不变，因此大量整合素和血小板黏附到吸附Fib上，且几乎所有黏附血小板都被活化。

Abstract：Quartz crystal microbalance with dissipation (QCM-D) and dual polarization interferometry (DPI) were used to investigate fibrinogen (Fib) adsorption behavior on different surfaces by changing the pH value. Moreover, integrin adhesion to the adsorbed Fibs was studied using DPI. Qualitative and quantitative studies of platelet adhesion to the adsorbed Fibs were performed using scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), and released lactate dehydrogenase (LDH) assay. Experimental results indicated that the conformation and orientation of the absorbed Fibs depended on surface property and pH cycling. For the hydrophilic surface, Fibs adsorbed at pH 7.4 presented an αC-hidden orientation, so no integrin adhesion was observed and a small number of platelets were adhered. By changing the rinsing solution pH from 7.4 to 3.2 and then back to 7.4, the adsorbed Fib orientation became αC-exposed via the transformation of Fib conformation during pH cycling, so integrin adhesion was more likely to occur and more platelets were adhered and activated. For the hydrophobic surface, the adsorbed Fibs became more spread and stretched due to the strong interaction between the Fibs and surface, and the αC-exposed orientation remained unchanged during pH cycling. Therefore, a large number of integrins and platelets were adhered to the adsorbed Fibs, and almost all of the adhered platelets were activated.

论文链接：https://doi.org/10.1021/acs.langmuir.5b04238