Effect of Two C-Terminal Side Chymotryptic Troponin T Subfragments on the Ca2+ Sensitivity of Superprecipitation and ATPase Activities of Actomyosin1

Abstract

The troponin T2 (m.w. 13,000) subfragment showed a Ca2+ sensitizing action on the superprecipitation and ATPase activities of actomyosin in the presence of tropomyosin, troponin I, and troponin C. On the other hand, troponin T2 beta (m.w. 11,000), the properties of which were similar to those of troponin T2 alpha except for the lower affinity for tropomyosin, did not show the Ca2+ sensitizing action.