Cystine plug and other novel mechanisms of large mechanical stability in dimeric proteins

TL;DR

This paper uncovers three dimeric proteins with anisotropic mechanostability exceeding 1 nN, highlighting novel topological mechanisms like the cystine plug that offer exceptional resistance and potential elastomer applications.

Contribution

It introduces a new topological mechanism, the cystine plug, demonstrating its superior mechanical stability in dimeric proteins compared to known clamps.

Findings

Cystine plug provides the highest resistance to stretching.

Three distinct mechanical clamps identified: shear-based, cystine slipknot, and cystine plug.

Mechanostability exceeds 1 nN along certain directions.

Abstract

We identify three dimeric proteins whose mechanostability is anisotropic and should exceed 1 nN along some directions. They come with distinct mechanical clamps: shear-based, involving a cystine slipknot, and due to dragging of a cystine plug through a cystine ring. The latter two mechanisms are topological in nature and the cystine plug mechanism has not yet been discussed but it turns out to provide the largest resistance to stretching. Its possible applications in elastomers are discussed.