A quasi-elastic light scattering study of smooth muscle myosin in the presence of ATP

We have investigated the hydrodynamic properties of turkey gizzard smooth muscle myosin in solution using quasi-elastic light scattering (QELS). The effects of ionic strength (0.05–0.5 M KCl) and light chain phosphorylation on the conformational transition of myosin were examined in the presence of ATP at 20 degrees C. Cumulant analysis and light scattering models were used to describe the myosin system in solution. A nonlinear least squares fitting procedure was used to determine the model that best fits the data. The conformational transition of the myosin monomer from a folded form to an extended form was clearly demonstrated in a salt concentration range of 0.15–0.3 M KCl. Light chain phosphorylation regulates the transition and promotes unfolding of the myosin. These results agree with the findings obtained using sedimentation velocity and electron microscopy (Onishi and Wakabayashi, 1982; Trybus et al., 1982; Trybus and Lowey, 1984). In addition, we present evidence for polymeric myosin coexisting with the two monomeric myosin species over a salt concentration range from 0.05 to 0.5 M KCl. The size of the polymeric myosin varied with salt concentration. This observation supports the hypothesis that, in solution, a dynamic equilibrium exists between the two conformations of myosin monomer and filaments

Additional file 2: of Development of a complex intervention for people with chronic pain after knee replacement: the STAR care pathway

Overview of STAR assessment clinic appointment, telephone follow-up and recommended treatment referral pathways. (DOCX 18 kb

Additional file 1: of Clinical- and cost-effectiveness of the STAR care pathway compared to usual care for patients with chronic pain after total knee replacement: study protocol for a UK randomised controlled trial

SPIRIT checklist. (DOCX 23 kb