Many-body forces between membrane inclusions: A new pattern-formation mechanism

The elastic interaction of membrane inclusions provides a unique physical r ealization of multibody forces. We derive an expression for the multibody c urvature interaction between membrane proteins, and show that this interact ion cannot be approximated by a pairwise additive theory. However, the inte raction can be decomposed into a repulsive pairwise part and a non-pairwise part of similar magnitude which is anisotropic and can be attractive. This non-pairwise interaction can create stable spatial patterns which arise fr om an interplay between thermal fluctuations and competing pairwise repulsi ve and non-pairwise attractive interactions. We present numerical simulatio ns which show how aggregates can assemble into ordered patterns from a rand om initial distribution at room temperature.