Two distinct binding affinities of poliovirus for its cellular receptor
Two distinct binding affinities of poliovirus for its cellular receptor
复制标题
DOI：
10.1074/jbc.m002146200
复制
发表时间：
2000-07-28
影响因子：
4.8
通讯作者：
Racaniello, VR
中科院分区：
文献类型：
--
作者：
McDermott, BM;Rux, AH;Racaniello, VR
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，我们利用表面等离子体共振来检测受体的可溶性形式与脊髓灰质炎病毒之间的相互作用。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、中和病毒的感染性，并诱导病毒颗粒的结构变化。结合研究表明，在1型脊髓灰质炎病毒衣壳上存在两个受体结合位点，在20℃时的亲和常数分别为\(K_{D1}=0.67\ \mu M\)和\(K_{D2}=0.11\ \mu M\)。这两个结合位点的相对丰度随温度而变化。在20℃时，\(K_{D2}\)位点约占传感器芯片上总结合位点的46%，并且其相对丰度随着温度降低而降低，以至于在5℃时，\(K_{D2}\)位点的相对丰度仅为总结合位点的12%。在所有测试温度下，\(K_{D1}\)位点的绝对水平相对保持恒定。这两个结合位点可能对应于病毒衣壳上受体结构域1的停靠位点，正如脊髓灰质炎病毒 - 受体复合物模型所预测的那样。或者，这些结合位点可能是结构“呼吸”的结果，或者可能是由受体诱导的病毒构象变化所导致的。
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-D1 = 0.67 mu M and K-D2, = 0.11 mu M. The relative abundance of the two binding sites varies with temperature. At 20 circle C, the K-D2 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-D2 site is only 12% of the total binding sites. Absolute levels of the K-D1 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.