Curvature sensing of curvature-inducing proteins with internal structure

Many types of peripheral and transmembrane proteins can sense and generate membrane curvature. Laterally isotropic proteins and crescent proteins with two-fold rotational symmetry, such as Bin/Amphiphysin/Rvs superfamily proteins, have been studied theoretically. However, proteins often have an asymmetric structure or a higher rotational symmetry. We theoretically studied the curvature sensing of proteins with asymmetric structures and structural deformations. First, we examined proteins consisting of two rod-like segments. When proteins have mirror symmetry, their sensing ability is similar to that of single-rod proteins, and second- or first-order transition occurs on the cylindrical membrane of a middle or small radius, respectively. As asymmetry is introduced, this transition becomes a continuous change, and metastable states appear at high protein densities. Protein with three-, five-, or more-fold rotational symmetry has laterally isotropic bending energy. However, when an asymmetric structural deformation is allowed, they can have a preferred orientation and stronger curvature sensing.Comment: 10 pages, 10 figure