Myosin is the main motor protein in skeletal muscle, its structure and dynamics in relaxed tissue strongly affect whole-body basal metabolism. This specific mechanism has recently been unveiled and its physiological and pathological implications are yet to be identified. In this project, biochemical and biophysical techniques will be applied to the study of myosin Super Relaxed State. A library of newly synthesized molecules has recently been obtained to first modulate the stability of the myosin SRX state in vitro and in vivo.