Table 2.

Estimates of myosin nucleotide handling rates from fits of the cross-bridge detachment rate (2πc) vs. [MgATP] relationships to Eq. (2) for cTnI(WT) and cTnI-MD truncations at 1.9 and 2.2µm SLs (mean ± SEM).

	cTnI(WT)		cTnI(1–167)		cTnI(1–193)
	1.9µm	2.2µm	1.9µm	2.2µm	1.9µm	2.2µm
k−ADP (S−1)	109.8±1.96	74.01±1.75*	69.1±1.96†	55.51±2.66*†	114.6±3.25#	99.15±2.13*†#
K+ATP (mM−1 S−1)	950.6±69.17	813.8±68.56	506.9±55.84†	589.9±122.3	585.5±57.98†	437.2±3 1.36†
n fibers	6	6	7	7	6	6

k_−ADP, cross-bridge MgADP release rate; k_+ATP, cross-bridge MgATP binding rate

^*Effect of SL for each truncation or wild-type; P <0.05

^†Truncation effect compared to cTnI(WT) at same SL; P <0.05

^#Difference between cTnI(1–193) and cTnI(1–167) at same SL; P <0.05