Bending of smooth muscle myosin rod

FEBS Letters

Cross, R.A.¹ 

[1] Institute of Molecular Biology, Austrian Academy of Sciences, Billrothstrasse 11, A-5020 Salzburg, Austria

关键词: Smooth muscle myosin;    Myosin rod;    Myosin hinge;    LMM;    light meromyosin;    SF 2;    heavy meromyosin subfragment 2;    PAGE;    polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(84)80940-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Electron microscopy of mammalian smooth muscle myosin rods showed them to be 153 ± 7nm (SD) long, and to bend sharply (> 90°) but infrequently, and pH independently (range 6.5–9.5), at a single site 45 ± 4 nm from one end of the molecule. Light meromyosin (LMM) preparations were 99 ± 10 nm long, and showed no bends. Intrinsic viscosity vs temperature plots for rods and LMM indicated that neither fragment changed in flexibility in the range 4–40° C. Peptide mapping in the presence and absence of SDS established that the proteolytic susceptibility of the hinge at the N terminus of LMM reflects the presence of locally different structure, and not simply a clustering of susceptible residues. The isolated smooth muscle myosin rod thus contains only a single hinge, having significant stiffness, and lacks the second bend seen under certain conditions in the intact molecule.

【 授权许可】

Unknown