Table 1. Normalized pCa–tension relationship in detergent-skinned rat heart muscle fibre bundles reconstituted with recombinant c-myc-tagged rat cTnT constructs.

	WT-cTnT	E162DEL	K211DEL
Normal rat hearts
″pCa50	5.55 ± 0.01	5.64 ± 0.02*	5.46 ± 0.02*
″n	3.9 ± 0.2	2.8 ± 0.1*	4.2 ± 0.2
PTU-treated rat hearts
″pCa50	5.54 ± 0.02	5.66 ± 0.03*	5.47 ± 0.03*
″n	4.1 ± 0.2	3.1 ± 0.1*	4.5 ± 0.3

Values are means ± s.e.m. Data from normalized pCa–tension measurements were fitted to the Hill equation by using a non-linear least square regression procedure to derive pCa₅₀ and the Hill coefficient (n). pCa₅₀ and n were determined separately from each muscle fibre experiment and the values averaged. WT-cTnT represents WT-cTnT + cTnI + cTnC reconstituted muscle fibres; E162DEL represents cTnT_E162DEL + cTnI + cTnC reconstituted muscle fibres and K211DEL represents cTnT_K211DEL + cTnI + cTnC reconstituted muscle fibres. Number of determinations is at least eight for each. Statistical differences were analysed using two-way ANOVA as described in the Methods.

^*P < 0.05.