The actin affinity and T_M from the ellipticity at 222 nm and DSC melts.

aThe values for Kapp, shown with standard errors. The data were fit to the Hill equation, and the Kapp and αH, Hill coefficient, are those reported by SigmaPlot (Figure 6). bTM1 and TM2 represent the tropomyosin transitions obtained in the absence of F-actin. TM3 is the transition corresponding to tropomyosin dissociation from F-actin (Figure 3). The ΔΔH value was obtained by subtracting the total ΔH values of the endotherms in the presence and absence of F-actin. The difference is proportional to the amount of energy required for dissociation of tropomyosin bound F-actin. cTM is the point at which 50% of tropomyosin is unfolded (Figure 2). The experimental conditions differ for the three analyses and are described in the Materials and Methods as well as the figure legends. The values can be compared on a relative rather than absolute basis.