Pyrophosphate-accelerated Actin Denaturation Mechanism in Myofibril
Actin denaturation upon ATP or pyrophosphate (PPi) addition has been studied in carp myofibril dissolved in 0.5M KCl. ATP-treatment of myofibril remarkably decreased its Mg-ATPase activity with no loss of Ca-ATPase activity. The treated myofibril has a quick inactivation phase in its Ca-ATPase inactivation profile. ATP dissociated myosin from actin. These are all reproduced also by PPi. PPi-induced actin denaturation in the myofibril involves PPi-induced actin dissociation from myosin and a subsequent denaturation of dissociated actin by 0.5 M KCl present in the medium. Ammonium sulfate as high as 1.75M causes no actin denaturation. It was concluded, therefore, that actin is protected from KC1 (or NaCl)-induced denaturation by binding to myosin.
- Fisheries science : FS
Fisheries science : FS 62(2), 307-311, 1996