Dynamic light-scattering study of synthetic myosin filaments

✍ Scribed by Noriko Mochizuki-Oda; Satoru Fujime

• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 790 KB
• Volume: 27
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360270906

✦ Synopsis

Synthetic myosin filaments of rabbit were prepared. Electron microscopy showed that the number-average length ( L , = 470 nm) and sharpness in length distribution ( L J L , = 1.03,) were independent of ionic strengths of 134, 74, and 44 mM, whereas the number ratio of M-filaments (about 15 nm in diameter at the bare zone) to m-filaments (about 10 nm) strongly depended on ionic strength (IS); the major filaments were M-filaments at IS = 134 mM, m-filaments at IS = 74 mM, and almost exclusively m-filaments at IS = 44 mM. Dynamic light scattering showed that the change in diameter with the change in ionic strength by 2-h dialysis was reversible. Combination of dynamic light scattering and sedimentation studies suggested a dynamic equilibrium between Mand m-filaments. Dynamic light-scattering spectra at IS = 134 and 74 m M could be analyzed by a theory for rigid rods, whereas those at IS = 44 m M only by introducing semiflexibility of filaments, m-filaments are more flexible a t IS = 44 than at 74 mM.