A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, Moscow 119071, Russia.
Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny, Moscow Region 141700, Russia.
Phys Rev E. 2019 Feb;99(2-1):022401. doi: 10.1103/PhysRevE.99.022401.
Amphipathic alpha-helical peptides, among other peripheral components of plasma membranes, are promising antimicrobial agents. Partial incorporation of a peptide into a lipid monolayer causes elastic deformations. Deformations induced by two peptides distant from each other are independent; when peptides get closer, interference between the deformations causes effective lateral interaction. We quantified the energy of membrane deformations for arbitrary configuration of two amphipathic peptides on the membrane surface. The global minimum of the deformation energy proved to be achieved when two parallel peptides are in registry at the distance of about 6 nm between the axes of peptides. The energy calculated in the unidimensional approach provides a good approximation for the dependence of the energy of peptides being in the registered configuration upon the distance between them, valid for a broad range of peptide lengths. The effective interactional length of peptides for the unidimensional approach is close to their actual length. If two parallel peptides are shifted along their axes with respect to each other, the interaction energy is also well approximated by the unidimensional potential, within the projection of one peptide onto the other. In the case when the axes of alpha helices cross at a substantial angle, the main contribution to peptide interactions comes from their edges: the effective length of peptides for the unidimensional approach is almost equal to the characteristic length of decay of deformations. Based on the results we obtained it can be concluded that interaction of membrane inclusions is quite adequately described by the potential calculated in the unidimensional approach.
两亲性 α-螺旋肽，以及其他质膜外周成分，都是很有前途的抗菌剂。肽的部分掺入单层脂质会引起弹性变形。彼此远离的两个肽引起的变形是独立的；当肽彼此靠近时，变形之间的干扰会导致有效的横向相互作用。我们量化了任意两个两亲性肽在膜表面上配置的膜变形能。当两个平行肽在约 6nm 的肽轴之间处于配准状态时，变形能的全局最小值被证明是达到的。在一维方法中计算的能量为处于配准构型的肽之间的距离的能量依赖性提供了很好的近似值，对于广泛的肽长度都有效。对于一维方法，肽的有效相互作用长度接近其实际长度。如果两个平行肽相对于彼此沿其轴移动，则有效相互作用能量也可以通过一维势很好地近似，在一个肽投影到另一个肽的情况下。当 α 螺旋的轴以较大角度交叉时，肽相互作用的主要贡献来自它们的边缘：对于一维方法，肽的有效长度几乎等于变形衰减的特征长度。基于我们获得的结果，可以得出结论，通过在一维方法中计算的势可以相当准确地描述膜包含物的相互作用。
