Topological Solitons and Folded Proteins

TL;DR

This paper introduces a novel topological soliton model for protein folding, representing loops as domain-wall solitons that connect secondary structures, successfully reproducing protein motifs with high accuracy.

Contribution

It presents a simple theoretical framework that models protein loops as topological solitons, enabling accurate folding predictions for biologically active proteins.

Findings

Successfully modeled protein secondary structures with ~0.7 Å accuracy

Reproduced alpha-helix and beta-sheet motifs using solitons

Applied model to multiple proteins with consistent results

Abstract

We propose that protein loops can be interpreted as topological domain-wall solitons. They interpolate between ground states that are the secondary structures like alpha-helices and beta-strands. Entire proteins can then be folded simply by assembling the solitons together, one after another. We present a simple theoretical model that realizes our proposal and apply it to a number of biologically active proteins including 1VII, 2RB8, 3EBX (Protein Data Bank codes). In all the examples that we have considered we are able to construct solitons that reproduce secondary structural motifs such as alpha-helix-loop-alpha-helix and beta-sheet-loop-beta-sheet with an overall root-mean-square-distance accuracy of around 0.7 Angstrom or less for the central alpha-carbons, i.e. within the limits of current experimental accuracy.