TABLE 3.

Summary of pCa-force relationship curves in reconstituted porcine skinned fibers at pH 7.0

The pCa₅₀, n_H, maximal force, and % Ca²⁺ unregulated force values are the average of many independent fiber experiments, and the errors are the S.E. values. The Ca²⁺- unregulated force was calculated by the equation (F_pCa8/F_pCa4) × 100, where the F_pCa8 and F_pCa4 are the force at pCa 8.0 and pCa 4.0 solutions, respectively. p values compare the RCM mutant against the TnT3-WT or TnT1-WT. HSSTnI, human SSTnI.

TnT	TnI	pCa50	ΔpCa50a	Hill coefficient, nH	% Maximal force	% Ca2+ unregulated force	No. experiments
HCTnT3-WT	HCTnI	5.67 ± 0.01		2.83 ± 0.12	50.81 ± 3.36	90.30 ± 2.75	12
HCTnT3-ΔN100/ΔE101	HCTnI	5.86 ± 0.02b	+0.19	1.94 ± 0.09b	51.30 ± 2.90	91.79 ± 3.95	10
HCTnT3-ΔN100	HCTnI	5.96 ± 0.03b	+0.29	1.84 ± 0.08b	54.73 ± 3.09	93.77 ± 3.03	13
HCTnT3-ΔE101	HCTnI	5.39 ± 0.01b	−0.28	3.14 ± 0.32	28.40 ± 1.98b	99.33 ± 0.45b	8
HCTnT1-WT	HSSTnI	5.78 ± 0.02		2.05 ± 0.11	44.43 ± 1.56	96.46 ± 1.62	11
HCTnT1-ΔN110/ΔE111	HSSTnI	5.82 ± 0.02	+0.04	2.11 ± 0.05	55.12 ± 3.08b	87.60 ± 3.76b	8
HCTnT1-ΔN110	HSSTnI	5.82 ± 0.03	+0.04	2.40 ± 0.10	56.02 ± 2.09b	88.42 ± 4.22b	6
HCTnT1-ΔE111	HSSTnI	5.49 ± 0.04b	−0.29	2.83 ± 0.33	21.83 ± 4.30b	95.13 ± 2.29	6

^a TnT3-RCM pCa₅₀ − TnT3-WT pCa₅₀ or TnT1-RCM pCa₅₀ −TnT1-WT pCa₅₀.

^b p < 0.05.