McDermott B M, Rux A H, Eisenberg R J, Cohen G H, Racaniello V R
Department of Microbiology, Columbia University College of Physicians & Surgeons, New York, New York 10032, USA.
J Biol Chem. 2000 Jul 28;275(30):23089-96. doi: 10.1074/jbc.M002146200.
To study the kinetics and equilibrium of poliovirus binding to the poliovirus receptor, we used surface plasmon resonance to examine the interaction of a soluble form of the receptor with poliovirus. Soluble receptor purified from mammalian cells is able to bind poliovirus, neutralize viral infectivity, and induce structural changes in the virus particle. Binding studies revealed that there are two binding sites for the receptor on the poliovirus type 1 capsid, with affinity constants at 20 degrees C of K(D)(1) = 0.67 microm and K(D)(2) = 0.11 microm. The relative abundance of the two binding sites varies with temperature. At 20 degrees C, the K(D)(2) site constitutes approximately 46% of the total binding sites on the sensor chip, and its relative abundance decreased with decreasing temperature such that at 5 degrees C, the relative abundance of the K(D)(2) site is only 12% of the total binding sites. Absolute levels of the K(D)(1) site remained relatively constant at all temperatures tested. The two binding sites may correspond to docking sites for domain 1 of the receptor on the viral capsid, as predicted by a model of the poliovirus-receptor complex. Alternatively, the binding sites may be a consequence of structural breathing, or could result from receptor-induced conformational changes in the virus.
为了研究脊髓灰质炎病毒与脊髓灰质炎病毒受体结合的动力学和平衡，我们使用表面等离子体共振来检测可溶性受体形式与脊髓灰质炎病毒的相互作用。从哺乳动物细胞中纯化的可溶性受体能够结合脊髓灰质炎病毒、中和病毒感染性并诱导病毒颗粒的结构变化。结合研究表明，1型脊髓灰质炎病毒衣壳上有两个受体结合位点，在20℃时的亲和常数分别为K(D)(1)=0.67微米和K(D)(2)=0.11微米。两个结合位点的相对丰度随温度变化。在20℃时，K(D)(2)位点约占传感器芯片上总结合位点的46%，其相对丰度随温度降低而降低，以至于在5℃时，K(D)(2)位点的相对丰度仅占总结合位点的12%。在所有测试温度下，K(D)(1)位点的绝对水平保持相对恒定。如脊髓灰质炎病毒-受体复合物模型所预测的，这两个结合位点可能对应于受体结构域1在病毒衣壳上的对接位点。或者，这些结合位点可能是结构波动的结果，也可能是受体诱导病毒构象变化的结果。
