Volanakis J E, Wirtz K W
Nature. 1979 Sep 13;281(5727):155-7. doi: 10.1038/281155a0.
C-Reactive protein (CRP), the most characteristic of the 'acute phase proteins' (ref. 1) is thought to participate in the mediation and/or modulation of acute inflammatory processes, but its exact function is unknown. CRP has a Ca2+-dependent binding specificity for phosphorylcholine, the polar head group of two widely distributed lipids, lecithin (phosphatidylcholine, PC) and sphingomyelin (SM). A number of observations suggest that at least some of the biological activities of CRP depend on its interaction with phospholipids of cell membranes. In addition, interaction of CRP with PC- and SM-containing lipid dispersions and with PC-containing liposomes can activate the complement system. We report here that binding of CRP to model membranes of PC requires the incorporation into the bilayer of lysophosphatidylcholine (LPC). Thus, a disturbance of the molecular organisation of the bilayer appears to be necessary for binding of CRP. These findings provide a possible biochemical explanation for binding of CRP to damaged but not intact cell membranes and might be relevant to its biological function.
C反应蛋白（CRP）是“急性期蛋白”中最具代表性的一种（参考文献1），被认为参与急性炎症过程的介导和/或调节，但其确切功能尚不清楚。CRP对磷酸胆碱具有钙离子依赖性结合特异性，磷酸胆碱是两种广泛分布的脂质（卵磷脂（磷脂酰胆碱，PC）和鞘磷脂（SM））的极性头部基团。一些观察结果表明，CRP的至少某些生物学活性取决于其与细胞膜磷脂的相互作用。此外，CRP与含PC和SM的脂质分散体以及含PC的脂质体的相互作用可激活补体系统。我们在此报告，CRP与PC模型膜的结合需要溶血磷脂酰胆碱（LPC）掺入双层膜中。因此，双层膜分子组织的紊乱似乎是CRP结合所必需的。这些发现为CRP与受损而非完整细胞膜的结合提供了一种可能的生化解释，并且可能与其生物学功能相关。
