Universidade Estadual do Ceará, Faculdade de Educação, Ciências e Letras de Iguatu, Iguatu, CE, Brazil.
Instituto Federal de Educação, Ciência e Tecnologia do Maranhão, Pinheiro, Maranhão, Brazil; Departamento de Física, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
Biosystems. 2023 Apr;226:104888. doi: 10.1016/j.biosystems.2023.104888. Epub 2023 Mar 28.
In this paper, we investigate the Casimir effect within a virus RNA, particularizing the study to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Then, we discuss the possibility of occurring damage or mutation in its genome due to the presence of quantum vacuum fluctuations inside and around the RNA ribbon. For this, we consider the geometry and the nontrivial topology of the viral RNA as having a simple helical structure. We initially compute the non-thermal Casimir energy associated to that geometry, considering boundary conditions that constrain the zero point oscillations of a massless scalar field to the cylindrical cavity containing a helix pitch of RNA ribbon. Then we extend the obtained result to the electromagnetic field and, following, we calculate the probability of occurring damage or mutation in RNA by using the normalized inverse exponential distribution, which suppresses very low energies, and consider cutoff (threshold) energies corresponding to UV-A and UV-C rays, surely responsible by mutations. Then, by taking into account UV-A, we arrive at a mutation rate per base per infection cycle, which in the case of the SARS-CoV-2 is non-negligible. We find a maximum value of this mutation rate for an RNA ribbon radius, applying it for SARS-CoV-2, in particular. We also calculate a characteristic longitudinal oscillation frequency for the helix pitch value corresponding to the local minimum of the Casimir energy. Finally, we consider thermal fluctuations of classical and quantum nature and show that the corresponding probability of mutation is completely negligible for that virus. Therefore, we conclude that only the nontrivial topology and the geometric attributes of the RNA molecule contribute to the possible mutations caused by quantum vacuum fluctuations in the viral genome.
本文研究了病毒 RNA 中的 Casimir 效应，特别关注严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）。然后，我们讨论了由于量子真空波动存在于 RNA 带内及其周围，其基因组是否会发生损伤或突变的可能性。为此，我们考虑病毒 RNA 的几何形状和非平凡拓扑结构具有简单的螺旋结构。我们最初计算了与该几何形状相关的非热 Casimir 能量，考虑了将无质量标量场的零点振动约束在包含 RNA 螺旋螺距的圆柱腔中的边界条件。然后，我们将得到的结果扩展到电磁场，并随之计算 RNA 中发生损伤或突变的概率，使用归一化指数分布来抑制非常低的能量，并考虑对应于 UV-A 和 UV-C 射线的截止（阈值）能量，它们肯定会导致突变。然后，考虑到 UV-A，我们得出了每感染循环每个碱基的突变率，对于 SARS-CoV-2，该突变率不可忽略。我们应用于 SARS-CoV-2，针对 RNA 带半径找到了这个突变率的最大值。我们还计算了对应于 Casimir 能量局部最小值的螺旋螺距值的特征纵向振荡频率。最后，我们考虑了经典和量子性质的热涨落，并表明对应于病毒的突变概率完全可以忽略不计。因此，我们得出结论，只有 RNA 分子的非平凡拓扑和几何属性才会导致病毒基因组中量子真空波动引起的可能突变。
