抄録
Abalone myosin was prepared by a more speedy method. The properties of this myosin were studied under various conditions with regard to their Mg-, Ca-, EDTA-ATPase and actin-activated ATPase activities.
The properties of abalone myosin ATPase were almost similar to those of scallop myosin, though the following differences were observed.
1. Ca-sensitivity of abalone myosin was higher than that of scallop myosin.
2. At neutral pH and 25°C, enzymatic activities were lower than those of scallop myosin, except in EDTA-ATPase activity.
3. PH activity curve of Mg-ATPase activity at low ionic condition was an U-shaped curve in contrast to the biphasic curve in scallop myosin. PH activity curves of EDTA-ATPase activity were bell-shaped curves with a peak at pH around 8.0, which was higher than that of scallop my-osin.
4. Arrhenius plots of abalone myosin ATPase activities showed no bending between 5-30°C which was different from that of scallop myosin.
The spccific cystein residue, so-called SHI was not dotected by the treatment of abalone myosin with NEM or PCMB.
