Tseng J, Mortensen R F
Department of Microbiology, Ohio State University, Columbus 43210.
Exp Cell Res. 1989 Feb;180(2):303-13. doi: 10.1016/0014-4827(89)90059-1.
We have previously reported that purified human C-reactive protein (CRP) specifically binds to the cell-binding region of plasma fibronectin (Fn) in a Ca2+-dependent reaction that is saturable at a molar ratio of CRP/Fn of approximately 9. In this study, the binding of CRP to Fn was found to interfere with the cell-attachment promoting activity of Fn. The inhibition of cell attachment was dependent on the concentration of the CRP and involved the phosphorylcholine (PC) binding site of CRP since inhibition was prevented by allowing the CRP to react with either PC (or closely related monophosphate compounds) or a mAb specific for the PC-binding site of CRP. Binding of CRP to laminin was also Ca2+-dependent; however, this binding did not alter the cell-attachment promoting activity of laminin. CRP by itself does not mediate cell attachment. Since CRP is selectively deposited at sites of tissue damage along with plasma Fn and has the ability to bind to Fn and alter its cell-binding activity, CRP may modulate early events in tissue repair.
我们之前曾报道，纯化的人C反应蛋白（CRP）在Ca2+依赖的反应中特异性结合血浆纤连蛋白（Fn）的细胞结合区域，该反应在CRP/Fn摩尔比约为9时达到饱和。在本研究中，发现CRP与Fn的结合会干扰Fn的细胞附着促进活性。细胞附着的抑制取决于CRP的浓度，且涉及CRP的磷酸胆碱（PC）结合位点，因为通过使CRP与PC（或密切相关的单磷酸化合物）或针对CRP的PC结合位点的单克隆抗体反应可防止抑制作用。CRP与层粘连蛋白的结合也是Ca2+依赖的；然而，这种结合并未改变层粘连蛋白的细胞附着促进活性。CRP本身不介导细胞附着。由于CRP与血浆Fn一起选择性沉积在组织损伤部位，并且具有结合Fn并改变其细胞结合活性的能力，因此CRP可能调节组织修复的早期事件。
