Topological potentials guiding protein self-assembly
Abstract
The simulated self-assembly of molecular building blocks into functional complexes is a
key area of study in computational biology and materials science. Self-assembly
simulations of proteins using physically-motivated potentials for non-polar
interactions, can identify the biologically correct assembly as the energy-minimizing
state. Short-range potentials, however, produce rugged energy landscapes, which lead to
simulations becoming trapped in non-functional local minimizers. Successful self-assembly
simulations depend on the physical realism of the driving potentials as well as
their ability to efficiently explore the configuration space. We introduce a long-range
topological potential, quantified via weighted total persistence, and combine it with
the morphometric approach to solvation-free energy. This combination improves the
assembly success rate in simulations of the tobacco mosaic virus dimer and other protein
complexes by up to sixteen-fold compared with the morphometric model alone. It further
enables successful simulation in systems that don't otherwise assemble during the
examined timescales. Compared to previous topology-based work, which has been primarily
descriptive, our approach uses topological measures as an active energetic bias that is
independent of electrostatics or chemical specificity and depends only on atomic
coordinates. Therefore, the method can, in principle, be applied to arbitrary systems
where such coordinates are optimized. Integrating topological descriptions into an
energy function offers a general strategy for overcoming kinetic barriers in molecular
simulations, with potential applications in drug design, materials development, and the
study of complex self-assembly processes.