Restoration of Ca2+-Activated Tension of CDTA-Treated Single Skeletal Muscle Fibers by Troponin C1

Abstract
Single fibers from glycerinated rabbit psoas muscle were treated with a solution containing CDTA, a strong chelator of metal ions. The CDTA-treated fibers lost all of the troponin C and showed no Ca2+ tension development. The addition of troponin C restored the Ca2+ -activated tension of CDTA-treated fibers. The tension-pCa relationship in the case of the CDTA-treated fibers reconstituted with troponin C was almost the same as that in the case of the same fibers before the CDTA treatment. These results are consistent with those of the previous study on the Ca2+ -activated ATPase of CDTA-treated rabbit skeletal myofibrils (Morimoto, S.& Ohtsuki, I.(1987) J. Biochem. 101, 291-301).