TO BUILD A VIRUS CAPSID - AN EQUILIBRIUM-MODEL OF THE SELF-ASSEMBLY OF POLYHEDRAL PROTEIN COMPLEXES
TO BUILD A VIRUS CAPSID - AN EQUILIBRIUM-MODEL OF THE SELF-ASSEMBLY OF POLYHEDRAL PROTEIN COMPLEXES
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DOI：
10.1006/jmbi.1994.1473
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发表时间：
1994-08-05
影响因子：
5.6
通讯作者：
ZLOTNICK, A
中科院分区：
文献类型：
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作者：
ZLOTNICK, A
球形（二十面体）病毒的衣壳由60个亚基的倍数构成。这些聚合物如何组装的问题是理解病毒生命周期的基础。本文提出了一种描述病毒组装过程的形式，它是外壳蛋白亚基、组装中间体和完整病毒之间的平衡。这种病毒组装的平衡模型与病毒组装的实验观察一致。在平衡状态下，无论是完整的病毒或游离亚基都是优势物种，预计组装中间体仅以痕量浓度存在。组装病毒在平衡时的浓度预计是高度浓度依赖性的，并且类似于高度协同反应，尽管该模型没有明确包括协同性。对于多面体的统计组装，不一定需要核，并且聚合可以通过级联的双分子反应而不是单个更高阶反应进行。因此，组装动力学不一定显示典型的有核蛋白质聚合的极端浓度依赖性。适度的亚基间相互作用能导致非常稳定的衣壳;因此，这种相互作用能的微小变化可以导致衣壳-亚基平衡的显著变化。核和蛋白质-核酸相互作用对病毒组装和衣壳形态的一些可能的影响被认为是。
The capsids of spherical (icosahedral) viruses are constructed of multiples of 60 subunits. The question of how these polymers assemble is basic to understanding the viral life cycle. A formalism describing virus assembly as an equilibrium between coat protein subunits, assembly intermediates and intact virus is presented. This equilibrium model of virus assembly is consistent with experimental observations of virus assembly. At equilibrium, either intact virus of free subunits are dominant species, assembly intermediates are predicted to be found only in trace concentrations. The concentration of assembled virus at equilibrium is expected to be extremely concentration-dependent and resemble a highly cooperative reaction although the model does not explicitly include cooperativity. For statistical assembly of a polyhedron, a nucleus is not necessarily required and polymerization can proceed through a cascade of bimolecular reactions rather than a single higher order reaction. Thus, kinetics of assembly do not necessarily show the extreme concentration dependence typical of nucleated protein polymerization. Modest intersubunit interaction energies result in a very stable capsid; consequently, a small change in this interaction energy can result in a considerable change in the capsid-subunit equilibrium. Some possible effects of nucleation and protein-nucleic acid interactions on virus assembly and capsid morphology are considered.