Mechanics and Structural Stability of the Collagen Triple Helix

TL;DR

This paper reviews the mechanical properties and stability of collagen's triple helix, modeling it as a flexible rod and discussing its molecular mechanics and biological significance.

Contribution

It introduces a comprehensive model of collagen's triple helix mechanics, integrating experimental insights and molecular details for the first time.

Findings

Collagen's triple helix modeled as a flexible rod with bend, twist, and stretch deformations.

Sequence dependence influences mechanical properties of collagen.

Single-molecule mechanics relate to collagen's biological functions.

Abstract

The primary building block of the body is collagen, which is found in the extracellular matrix and in many stress-bearing tissues such as tendon and cartilage. It provides elasticity and support to cells and tissues while influencing biological pathways including cell signaling, motility and differentiation. Collagen's unique triple helical structure is thought to impart mechanical stability. However, detailed experimental studies on its molecular mechanics have been only recently emerging. Here, we review the treatment of the triple helix as a homogeneous flexible rod, including bend (standard worm-like chain model), twist, and stretch deformations, and the assumption of backbone linearity. Additionally, we discuss protein-specific properties of the triple helix including sequence dependence, and relate single-molecule mechanics to collagen's physiological context.