发表机构
University of Warsaw; Polish Academy of Sciences; Jožef Stefan Institute; University of Chinese Academy of Sciences（华沙大学; 波兰科学院; 约瑟夫·斯蒂芬研究所; 中国科学院大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过泊松-玻尔兹曼理论揭示，包装的DNA基因组赋予病毒长程静电各向异性，其源于逆线轴DNA结构，影响病毒间及病毒-壁相互作用，并以噬菌体λ验证。
AI 中文摘要
病毒是生物学中带电量最高的物体之一，静电相互作用几乎渗透其生命周期的每个阶段。同时，就周围电解质而言，空的二十面体衣壳几乎是各向同性的——其电荷分布仅在高多极阶下呈现各向异性，而静电屏蔽在远距离探测到这种各向异性之前就已将其消除。在此，我们表明，填充病毒中包装的基因组赋予了一种贯穿周围介质的长程静电各向异性，而这种各向异性在空衣壳中并不存在。我们通过一种新颖的泊松-玻尔兹曼连续介质理论支持这些发现，其中双链DNA的取向有序通过各向异性介电张量和非均匀体积电荷分布引入，并与包含衣壳蛋白可电离氨基酸残基的电荷调节壳层耦合。所得的静电势分布表明，以逆线轴几何结构包装的DNA在外部衣壳表面印刻了高度不均匀的电势分布，其角结构是DNA自由轴向空隙的直接结果。在高盐度下，该分布的多极谱在远距离处持续存在，而在低盐浓度下，高阶多极远离表面时衰减更快。存活的四极使病毒-壁和病毒-病毒相互作用在$k_\mathrm{B}T$水平上具有取向依赖性，其优选取向由外部电荷符号和pH控制。以噬菌体λ作为模型系统，并在另外两种噬菌体上检验结果的稳健性，我们在一系列pH和离子强度范围内发现了相同的行为。这确定了包装的基因组（而非衣壳的对称性）是填充病毒长程静电各向异性的起源。
英文摘要
Viruses are among the most highly charged objects in biology, and electrostatic interactions permeate nearly every stage of their life cycle. At the same time, an empty icosahedral capsid is almost isotropic as far as the surrounding electrolyte is concerned---its charge distribution is anisotropic only at high multipole order, and electrostatic screening removes such anisotropy long before it can be probed at a distance. Here, we show that the packaged genome of a filled virus imparts a long-range electrostatic anisotropy that extends throughout the surrounding medium, which is not present for empty capsids. We support these findings with a novel Poisson--Boltzmann continuum theory where the orientational order of dsDNA enters through an anisotropic dielectric tensor and an inhomogeneous volume-charge distribution, which is coupled to a charge-regulating shell containing ionizable amino acid residues of the capsid proteins. The resulting electrostatic potential profiles show that DNA packed in an inverse-spool geometry imprints a highly inhomogeneous potential distribution on the outer capsid surface, whose angular structure is a direct result of the DNA-free axial void. At high salinity, the multipole spectrum of this distribution persists at large distances, whereas at low salt concentration, higher-order multipoles decay more rapidly away from the surface. The surviving quadrupole renders virus--wall and virus--virus interactions orientation dependent at the $k_\mathrm{B}T$ level, with a preferred orientation controlled by the sign of the external charge and the pH. Using phage $λ$ as a model system and checking robustness of our results on two other phages, we find the same behavior across a range of pH and ionic strengths. This identifies the packaged genome, rather than the symmetry of the capsid, as the origin of the long-range electrostatic anisotropy of a filled virus.
Comments16 pages, 6 figures; 18 pages and 10 figures of Supporting Material
