3-Chlorodiphenylamine is able to bind highly (
K
d
=10 µM
) to a chimeric protein consisting of the regulatory N-domain of cTnC (cNTnC) and the switch region of cTnI (
cNTnC–cSp chimera
).3-Chlorodiphenylamine (100 µM) results in a 1.5-fold increase in the Ca
2+
sensitivity of force development without altering the maximal or resting forces in skinned ventricular trabeculae.3-Chlorodiphenylamine (25-100 µM) increases Ca
2+
sensitivity of the N-domain of intact cTnC after reconstitution into the cTn complex (cTnC complexed with cTnI and cTnT) in a concentration-dependent manner. It exhibits pCa
50
s with 6.39±0.01, 6.65±0.01, and 6.73±0.02 in the presence of 25, 50, and 100 µM 3-Chlorodiphenylamine, respectively.