Figure 7

Temperature dependence for Ca²⁺ sensitivity and maximum force of cardiac skinned fibres is more pronounced following reconstitution with D145E cTnC. The Ca²⁺ sensitivity (pCa 8.0 to 4.0) of isometric force was measured at (a) 15° (b) 25° and (c) 30 °C in fibres depleted of native cTnC and reconstituted with HcTnC WT (○) or D145E (●). Ca²⁺ sensitivity was measured at all three temperatures on each fibre. Each curve is normalised to its own maximum (at pCa 4.0). (d) In a different set, each fibre was reconstituted with one isoform and maximal tension was measured at 21 °C and at one other temperature (see Methods). Data are normalised to the value at 21 °C. *p < 0.05 compared to WT at the same temperature. In (a–d), values shown are means ± s.e.m. (n = 4–5). In some cases error bars fall within the symbols.