On collagen II fibrillogenesis

Abstract

Collagen fibrils exhibit noticeable differences in their molecular order in the direction perpendicular to fibril axis. For instance, three‐dimensional crystallinity prevails for type I collagen (e.g. tendons) whereas only liquid‐like order in the lateral direction prevails for type II collagen (e.g. cartilage). The latter situation has been likened to that of a smectic liquid crystal. It is suggested here that the fibrillogenesis of type II collagen is indeed directed by a possibly metastable liquid crystalline mesophase involving a supramolecular assembling process. The occurrence of decoration on the fibrillar surface enhances a liquid crystalline phase due to preferential growth assumed to continue along the axial direction, and an increasing persistence length with respect to triple‐helical collagen molecules.

Acknowledgements

The author expresses his great appreciation to Professors P. van der Schoot and T.J. Wess for reading the manuscript and for constructive criticism.