Table 5. Ca²⁺ sensitivity and maximum force generation in skinned papillary muscle fibers.

	n	pCa50	Hill Coefficient	Maximal Force (mN mm-2)	pCa50	Hill Coefficient	Maximal Force (mN mm-2)
Sarcomere length (μm)		1.9	1.9	1.9	2.3	2.3	2.3
Tnnt2R141W/+	3	5.41±0.03	2.88±0.32	52.2±10.2	5.58±0.08	2.43±0.31	73.3±13.7
WT	8	5.61±0.02	6.34±1.01	48.6±5.3	5.74±0.02	3.72±0.12	64.1±7.6
P		<0.001	<0.05	NS	<0.01	<0.001	NS

pCa₅₀, -log[Ca²⁺] required for generation of 50% of maximal force. n, number of skinned fibers studied. Data: mean±SE. P values correspond to the comparison between Tnnt2^R141W/+and WT fibers at the same sarcomere length. NS, not significant; WT, wildtype.