. 2012 Apr 6;287(23):19136–19147. doi: 10.1074/jbc.M111.323048

TABLE 1.

Mechanical characteristics of exchanged fiber bundles

Mechanical characteristics of skinned mouse cardiac fiber bundles exchanged with human cTn-containing wild type (Tn WT), Ser-150-pseudophosphorylated cTnI (Tn S150D), Ser-23/24-pseudophosphorylated cTnI (Tn S23D/S24D), or combined Ser-23/24- and Ser-150-pseudophosphorylated cTnI (Tn S23D/S24D/S150D). Values are the mean ± S.E. F_max, maximal tension development in mN/mm²; EC₅₀, the Ca²⁺ concentration in μm at 50% maximal force; Hill, slope of the tension-Ca²⁺ plot; ΔEC₅₀, the difference in the calcium concentration at 50% maximal force from 1.9 to 2.2 μm sarcomere length; n, number of fibers in each group.

Tn exchanged	1.9 μm			2.2 μm			ΔEC₅₀	n
Tn exchanged	F_max	EC₅₀	Hill	F_max	EC₅₀	Hill	ΔEC₅₀	n
Tn WT	21.2 ± 1.0	1.53 ± 0.03^a (P,PP,PPP)	2.85 ± 0.10^a (PP,PPP)	21.6 ± 1.3	1.27 ± 0.03^a (P,PP)	2.84 ± 0.12^a (PP,PPP)	0.26 ± 0.04^a (PP)	7
Tn S150D	22.8 ± 2.2	0.92 ± 0.01^a (W,PP,PPP)	2.50 ± 0.10^a (PP,PPP)	24.8 ± 2.4	0.76 ± 0.02^a (W,PP,PPP)	2.65 ± 0.17^a (PP,PPP)	0.16 ± 0.06^a (PP,PPP)	7
Tn S23D/S24D	20.5 ± 2.6	2.82 ± 0.05^a (W,P,PPP)	4.47 ± 0.17^a (W,P)	26.3 ± 4.5	2.31 ± 0.07^a (W,P,PPP)	3.85 ± 0.12^a(W,P)	0.52 ± 0.08^a (W,P)	8
Tn S23D/S24D/S150D	23.7 ± 2.1	1.80 ± 0.09^a (W,P,PP)	4.18 ± 0.29^a (W,P)	30.7 ± 4.0	1.43 ± 0.09^a (P,PP)	3.87 ± 0.18^a (W,P)	0.38 ± 0.04^a (P)	9

^a ANOVA = p < 0.05; W, significantly different vs. Tn WT; P, significantly different vs. Tn S150D; PP, significantly different vs. Tn S23D/S24D; PPP, significantly different vs. S23D/S24D/S150D.