筋収縮機構に関する研究 : Actomyosin系のHysteresisを中心として

We have reviewed our studies concerning the AM-system conducted in our laboratory during the past three years and have discussed the important features of hysteresis (Szent-Gyorgyi) of the AM-system. 1) We examined the reports by Szent-Gyorgyi's. group from various angles in regards to the viscosity-changes and the superprecipitation of the solution of AM, the ATPase activities, glycerol extracted muscle, freezing and subsequent thawing, etc. And we recognized that their data agreed with ours roughly. 2) In ditails, however, there were considerable disagreements. Particularly, it is noted that the molecular mechanism of the interaction between ,AM and ATP is yet unknown. 3) Pyrophosphate, ATP in high concentration and other substances can remove hysteresis from the AM-system. On the other hand, they can cause relaxation of glycerol extracted muscle and cause it to become transparent and elastic. From these reasons, it is concluded that the phenomena of relaxation of glycerol extracted muscle or the removal of its hysteresis in the same. 4) We suggest that glycerol extracted muscle as a muscle model, due to hysteresis of its AM-system, is unfavorable and that glycerol extracted muscle from which hysteresis has been removed by the above substances especially ATP may be better