Structural changes in chicken myosin subfragment-1 induced by high hydrostatic pressure

Abstract

ATP-induced fluorescence increment of pressurized S1 was almost the same as unpressurized one at least up to 150 MPa, whereas it decreased above 200 MPa. The binding of e-ADP to S1 decreased at 250–300 MPa. S1 pressurized at 100–250 MPa and unpressurized S1 bound to F-actin similarly, although binding of S1 to actin decreased when the pressure treatment was done above 250 MPa. S1 was easily cleaved by tryptic digestion into three domains. Tryptic fragments of S1 digested after pressure treatment were essentially the same as those of unpressurized one. On the other hand, additional fragments appeared when the digestion was performed under pressure at 300 MPa. It is concluded that pressure-induced structural changes of S1 begin to occur about 150 MPa, and ATPase and actin binding sites lose those intrinsic structures at 250–300 MPa.