POLYMER EXCLUSION, CELL ADHESION AND MEMBRANE-FUSION
POLYMER EXCLUSION, CELL ADHESION AND MEMBRANE-FUSION
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DOI：
10.1038/254695a0
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发表时间：
1975-01-01
期刊：
影响因子：
64.8
通讯作者：
MAROUDAS, NG
中科院分区：
文献类型：
--
作者：
MAROUDAS, NG
从物理化学研究成纤维细胞的粘附合成substrata1，2I建议，在一般情况下，表面结合的聚合物（例如吸附的血清蛋白）可能会抑制细胞附着，因为它们的空间排阻体积。这种效应在胶体科学中是众所周知的（法拉第使用明胶来稳定金溶胶3），但在细胞生物学中似乎没有得到广泛的重视。因此，最近对蛋白质和二价阳离子在细胞粘附中的作用的综述，被视为胶体稳定性的问题，仅讨论了电荷排斥和钙桥4。此外，关于细胞表面的标准文本5提出了经典的DLVO（Derjaguin，朗道，Verwey和Overbeek）理论，即电荷排斥对色散吸引，但忽略了Overbeek及其同事后来发展的原理，即即使是不带电的表面，如果被吸附的聚合物分子覆盖，也可能相互排斥6。我现在表明，质膜上的糖萼聚合物的空间排斥可以解释最近观察到的各种细胞的融合和附着。术语空间排斥3不仅包括刚性分子（如棒状和球状）的几何排斥，还包括不利的热力学参数，如许多链段上的自由能，以及对于无规卷曲聚合物，每个分子通过弯曲其链段而要求额外空间的能力所产生的熵。
FROM physicochemical studies on the adhesion of fibroblasts to synthetic substrata1,2I suggested that, in general, surface-bound polymers (for example adsorbed serum proteins) probably inhibit cell attachment because of their steric exclusion volume. This effect is well known in colloid science (Faraday used gelatin to stabilise gold sols3) but does not seem to be widely appreciated in cell biology. Thus, a recent review on the role of proteins and divalent cations in cell adhesion, viewed as a problem in colloid stability, discusses only charge repulsion and calcium bridging4. Furthermore, standard texts on the cell surface5present the classical DLVO (Derjaguin, Landau, Verwey and Overbeek) theory of charge repulsion against dispersive attraction, but omit the later development by Overbeek and coworkers of the principle that even uncharged surfaces, if covered by adsorbed polymer molecules, may repel each other6. I now show that steric exclusion by glycocalyx polymers on the plasma membrane would explain some recent observations on fusion and attachment, by a variety of cells. The term steric exclusion3comprises not only geometric exclusion by rigid molecules, such as rods and spheres, but also unfavourable thermodynamic parameters such as free energy, summed up over many segments, and, for random coil polymers, entropy resulting from the ability of each molecule to claim extra lebensraum by flexing its segments.