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. 2012 Feb 14;2012:657523. doi: 10.1155/2012/657523

Figure 4.

Figure 4

Influence of FHC-linked mutations in human cardiac troponin on temperature dependence of thin-filament sliding at pCa 5. Thin filaments were reconstituted with α-Tm and either rhcTn WT (circles, black), rhcTn TnI,R145G (triangles, green), rhcTn TnI,K206Q (squares, yellow), or rhcTn TnT, R278C (diamonds, blue). Data were obtained during the heating phases of multiple heating/cooling cycles, as in Figure 1; note that WT data were replotted from Figure 2(b). (a) Points represent the mean sliding speed for 3–8 filaments during 1 s. Note that speeds with TnI mutant K206Q [32] and TnT mutant R278C were generally elevated over WT. (b) Arrhenius analysis of data from (a). Symbols and colors as in (a); unregulated F-actin from the same series of experiments (Figure 2(b)) was also included in (b) (inverted triangle and dashed lines; light gray). Each dataset was fit by two linear regressions after omitting data above 60°C (WT), 54°C (cTnI R145G), 51.5°C (cTnI K206Q), or 55°C (cTnT R278C). Regression lines are shown without correction for temperature-dependent changes in solvent viscosity; points correspond to Tt, the intersection of each pair of lines. Filament sliding speeds are expressed in μm s−1.