Potentiation by adrenaline of a proteolytic activity associated with purified myosin.

Proteolytic activity accompanies myosin through three reprecipitations. The fact that this activity can be potentiated by very small doses of 1-adrenaline supports the view that adrenaline receptors are protein in nature and that adrenaline-like compounds exert their action through modification of the activity of enzymes.