Panel A shows light scattering as a function of myosin concentration for various NM 2A constructs. The x-axis represents myosin concentration in nanomolar ranging from 0 to 120 nanomolar, and the y-axis represents light scattering in arbitrary units ranging from 10,000 to 90,000 arbitrary units. Different constructs are represented by distinct symbols and colors. Panel B shows light scattering as a function of myosin concentration for various NM 2B and NM 2C constructs. The x-axis represents myosin concentration in nanomolar ranging from 0 to 120 nanomolar, and the y-axis represents light scattering in arbitrary units ranging from 10,000 to 90,000 arbitrary units. Different constructs are represented by distinct symbols and colors. Panel C shows the effect of sodium chloride concentration on the solubility of NM 2 constructs. The x-axis represents sodium chloride concentration in millimolar ranging from 0 to 500 millimolar, and the y-axis represents myosin concentration in the supernatant in nanomolar ranging from 0 to 140 nanomolar. Different constructs are represented by distinct symbols and colors.
NHT deletion does not affect the CC for NM-II polymerization in the absence of ATP. (A and B) CCs of NM-IIs for polymerization. NM-IIs at varying concentrations were incubated overnight as described in Fig. 1, and warmed to room temperature for 30 min, and light scattering was measured at 365 nm using a PTI fluorimeter. CC was determined from the intersection of the plotted curves for polymerized and monomeric myosin. Data represent the average of two independent experiments. (C) Effect of NHT deletion on NM-II solubility. Full-length and NHT-deleted NM-IIs (150 nM) were incubated as in Fig. 1 with varying NaCl concentrations. After centrifugation at 400,000 × g for 20 min to separate polymerized (pellet) and soluble (supernatant) myosin, the amounts of polymerized and unpolymerized myosin were determined by Coomassie-stained SDS-PAGE. Data represent the average of two independent experiments.