Nonthermal effects of the electromagnetic (EM) field in the radio and microwave frequency ranges on basic biological matter are difficult to detect and thus remain poorly understood. In this work, all-atom nonequilibrium molecular dynamics simulations were performed to investigate the molecular mechanisms of an amyloidogenic peptide response to nonionizing radiation of varying field characteristics. The results showed that the EM field induced peptide conformations dependent on the field frequency and strength. At the high field strength (0.7 V/nmrms), the peptide explored a wider conformational space as the frequency increased from 1.0 to 5.0 GHz. At the intermediate strength fields (0.07-0.0385 V/nmrms), the frequencies of 1.0 and 2.5 GHz resulted in the peptide being trapped in specific conformations, with 1.0 GHz enabling both fibril-forming and fibril-inhibiting conformations, while 2.5 GHz led to formation of mostly fibril-forming conformations. In contrast, the 5.0 GHz frequency caused increased peptide dynamics and more extended conformations with fibril-enabling aromatic side-chain arrangement akin to the structures formed under ambient conditions. All the simulated frequencies at low strength fields (0.007-0.0007 V/nmrms) resulted in the formation of amyloid-prone hairpin conformations similar to those formed under the weak static electric field and ambient conditions. These results suggest that specific ranges of EM field parameters produce peptide conformations unfavorable for formation of amyloid fibrils, a phenomenon that can be exploited in treatment and prevention of amyloid diseases. Alternatively, EM field parameters can be selected to modulate the formation of well-ordered peptide assemblies as a rational design strategy for engineering biocompatible materials.

中文翻译：

---

电磁场调节淀粉样肽的聚集倾向。

无线电和微波频率范围内的电磁（EM）场对基本生物物质的非热效应难以检测，因此人们对其了解甚少。在这项工作中，进行了全原子非平衡分子动力学模拟，以研究淀粉样肽对不同场特征的非电离辐射的响应的分子机制。结果表明，电磁场诱导的肽构象取决于场频率和强度。在高场强（0.7 V / nmrms）下，随着频率从1.0 GHz增加到5.0 GHz，该肽探索了更广阔的构象空间。在中间强度场（0.07-0.0385 V / nmrms）处，1.0和2.5 GHz的频率导致该肽被捕获为特定构象，其中1。0 GHz既可以形成原纤维，也可以抑制原纤维，而2.5 GHz可以形成大多数原纤维。相比之下，5.0 GHz频率导致增加的肽动力学，并具有类似于在环境条件下形成的结构的原纤化芳族侧链排列，从而扩展了构象。在低强度场（0.007-0.0007 V / nmrms）上进行的所有模拟频率均导致易发淀粉样发夹结构的形成，类似于在弱静电电场和环境条件下形成的发夹结构。这些结果表明，EM场参数的特定范围会产生不利于淀粉样蛋白原纤维形成的肽构象，这种现象可用于治疗和预防淀粉样蛋白疾病。或者，