Molecular structural basis of relaxation in skeletal muscle

Rapid relaxation following active contraction is essential to the efficient performance of both skeletal and cardiac muscle, but its mechanistic basis is poorly understood. The well-known decrease in intracellular calcium concentration is necessary but not sufficient for rapid relaxation, and there is likely to be an additional mechanical trigger. This proposal will use time-resolved X-ray diffraction to characterise the molecular structural changes in the muscle filaments during the relaxation of skeletal muscles of mammals, and their dependence on imposed mechanical perturbations. The results will help to elucidate the underlying molecular mechanisms, underpinning the development of novel therapies for disease in both skeletal muscle and in the heart.