Accumulation of phosphatidylcholine on gut mucosal surface is not dominated by electrostatic interactions
Accumulation of phosphatidylcholine on gut mucosal surface is not dominated by electrostatic interactions
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DOI：
10.1016/j.bbamem.2017.02.008
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发表时间：
2017-05-01
影响因子：
3.4
通讯作者：
Tanaka, Motomu
中科院分区：
文献类型：
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作者：
Korytowski, Agatha;Abuillan, Wasim;Tanaka, Motomu
磷脂酰胆碱（PC）在肠粘液层中的积累对于保护结肠上皮免受细菌攻击至关重要。据报道，PC的消耗是溃疡性结肠炎的一个显著特征。在这里，我们解决了PC如何与其结合蛋白（粘蛋白）相互作用的问题，粘蛋白可能会建立针对结肠微生物群的疏水屏障。在第一步中，二油酰磷脂酰胆碱（DOPC）的相互作用与两个粘蛋白制剂从猪胃，已经研究了使用动态光散射，zeta电位测量，和Langmuir等温线，表明粘蛋白结合到DOPC囊泡的表面。粘蛋白-PC相互作用的焓可以通过等温滴定量热法测定。两种粘蛋白类型对PC的高亲和力似乎是合理的，因为它们主要由粘蛋白2组成，粘蛋白2是流动粘液的主要成分。此外，通过净电荷的系统变化，我们得出结论，两性离子DOPC具有最强的结合亲和力，这不能在带电分子之间的静电相互作用内解释。(C)2017爱思唯尔B. V.保留所有权利。
The accumulation of phosphatidylcholine (PC) in the intestinal mucus layer is crucial for the protection of colon epithelia from the bacterial attack. It has been reported that the depletion of PC is a distinct feature of ulcerative colitis. Here we addressed the question how PC interacts with its binding proteins, the mucins, which may establish the hydrophobic barrier against colonic microbiota. In the first step, the interactions of dioleoylphosphatidylcholine (DOPC) with two mucin preparations from porcine stomach, have been studied using dynamic light scattering, zeta potential measurement, and Langmuir isotherms, suggesting that mucin binds to the surface of DOPC vesicles. The enthalpy of mucin-PC interaction could be determined by isothermal titration calorimetry. The high affinity to PC found for both mucin types seems reasonable, as they mainly consist of mucin 2, a major constituent of the flowing mucus. Moreover, by the systematic variation of net charges, we concluded that the zwitterionic DOPC has the strongest binding affinity that cannot be explained within the electrostatic interactions between charged molecules. (C) 2017 Elsevier B.V. All rights reserved.