KINETICS AND THERMODYNAMICS OF VIRUS BINDING TO RECEPTOR - STUDIES WITH RHINOVIRUS, INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1), AND SURFACE-PLASMON RESONANCE
KINETICS AND THERMODYNAMICS OF VIRUS BINDING TO RECEPTOR - STUDIES WITH RHINOVIRUS, INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1), AND SURFACE-PLASMON RESONANCE
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DOI：
10.1074/jbc.270.22.13216
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发表时间：
1995-06-02
影响因子：
4.8
通讯作者：
SPRINGER, TA
中科院分区：
文献类型：
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作者：
CASASNOVAS, JM;SPRINGER, TA
我们利用人鼻病毒血清型3（HRV3）、含免疫球蛋白超家族结构域1 - 5的可溶性细胞间黏附分子 - 1（ICAM - 1，CD54）（sICAM - 1）以及表面等离子体共振技术，研究了一种病毒与其受体相互作用的动力学和热力学。在HRV3上存在两类sICAM - 1结合位点，每类约占总位点的50%，其结合速率常数分别为2450 ± 300和134 ± 11 M⁻¹ s⁻¹。这些速率较低，与结合到鼻病毒峡谷中一个相对难以接近的位点相符。相比之下，三种单克隆抗体以17000 - 48000 M⁻¹ s⁻¹的单一速率常数与sICAM - 1结合。HRV3的解离速率常数为1.7 ± 0.1×10⁻³ s⁻¹，由此计算出的解离常数为0.7 ± 0.1和12.5 ± 1.2 μM。这与溶液中的饱和结合情况吻合良好，溶液中的饱和结合显示出两个丰度相似的位点，其K₍D₎为0.55 ± 0.2和5.7 ± 2.0 μM。具有IgA1 Fc区的ICAM - 1二价嵌合体以K₍D₎ = 50和410 nM结合，显示出亲和力增强了17倍。将pH从8.0降至6.0会使亲和力降低约50倍，主要是通过降低结合速率实现的。热力学测量表明，与单克隆抗体结合不同，ICAM - 1与HRV3的结合是吸热的。两类ICAM - 1结合位点吸收的热量分别为3.5和6.3 kcal/mol，这可能有助于受体介导的病毒粒子解体，病毒粒子解体的活化能约为42 kcal/mol。
We have studied the kinetics and thermodynamics of a virus interacting with its receptor using human rhinovirus serotype 3 (HRV3), soluble intercellular adhesion molecule-1 (ICAM-1, CD54) containing Ig superfamily domains 1-5 (sICAM-1), and surface plasmon resonance. There were two classes of binding sites for sICAM-1 on HRV3, each comprising about 50% of the total sites, with association rate constants of 2450 +/- 300 and 134 +/- 11 M(-1) s(-1). These rates are low, consistent with binding to a relatively inaccessible site in the rhinovirus canyon. By contrast, three monoclonal antibodies bound to sICAM-1 with a single rate constant of 17,000-48,000 M(-1) s(-1). The dissociation rate constant for RRV3 was 1.7 +/- 0.1 x 10(-3) s(-1), giving calculated dissociation constants of 0.7 +/- 0.1 and 12.5 +/- 1.2 mu M. Agreement was good with saturation binding in solution, which showed two sites of similar abundance with K-D of 0.55 +/- 0.2 and 5.7 +/- 2.0 mu M. A bivalent chimera of ICAM-1 with the IgA1 Fc region bound with K-D = 50 and 410 nar, showing 17-fold enhanced affinity. Lowering pH from 8.0 to 6.0 reduced affinity by approximately 50-fold, primarily by reducing the on rate. Thermodynamic measurements showed that binding of ICAM-1 to HRV3 is endothermic, by contrast to binding to monoclonal antibody. The heat that is absorbed of 3.5 and 6.3 kcal/mol for the two classes of ICAM-1 binding sites may contribute to receptor-mediated disruption of virions, which has an activation energy of about 42 kcal/mol.