01 Mar 2011 - Solving the structure of nature’s elasticity stretches the possibilities for engineering flexible materials

Copyright © Wellcome trust centre for Cell-Matrix Research Elastin is a protein that allows tissues to stretch, for example when the lungs expand and contract during breathing, or when arteries expand and contract as the heart beats. It is the co-ordinated assembly of many tropoelastins into elastin that gives tissues their stretchy properties. The high level of physical performance demanded of elastin vastly exceeds and outlasts all human-made synthetic elastic materials. New approaches to model the structure of elastin have now revealed key elements of the mechanism involved.

Discovery: We have found that tropoelastin is a curved, spring-like molecule with a ‘foot’ region to facilitate attachment to cells. Stretching and relaxing experiments showed that the molecule has the extraordinary capacity to extend to eight-times its initial length and then to return to its original shape with no loss of energy, making it a near-perfect spring. Our work therefore reveals how evolution has generated a molecule with near-perfect elasticity that will last a lifetime.

Implications: Elastic materials are used in applications as diverse as clothing, vehicles, tissue engineering and even space travel. Our work on precisely how the structure of tropoelastin creates exceptional elastic properties will open up new ways to develop improved synthetic ‘elastin-like’ polymers. It will also help to understand how changes in tissue elasticity characterise some human diseases, and will suggest new approaches to alleviate the problems this causes.

Structure of full-length tropoelastin calculated from X-ray scattering (blue), neutron scattering (grey) and a representation of the two overlayed with two shorter N-terminal constructs (pink and green).

Baldock C, Oberhauser AF, Ma L, Lammie D, Siegler V, Mithieux SM, Tu Y, Chow JY, Suleman F, Malfois M, Rogers S, Guo L, Irving TC, Wess TJ, Weiss AS.(2011) Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity. PNAS 108, 4322-7. PNAS