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On the flexibility of myosin in solution
Author(s) -
Curry James F.,
Krause Sonja
Publication year - 1991
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360311403
Subject(s) - myosin , chemistry , relaxation (psychology) , pyrophosphate , birefringence , flow birefringence , myosin head , myosin light chain kinase , analytical chemistry (journal) , nuclear magnetic resonance , chromatography , biochemistry , optics , physics , polymer , enzyme , psychology , social psychology , organic chemistry
Rabbit skeletal muscle myosin from the same rabbit was prepared by two different methods, and then purified by either Sephadex or hydroxylapatite chromatography. The resulting myosin samples were analyzed in 2–10 m M sodium pyrophosphate solutions at pH 9 using transient electric birefringence. The birefringence decay signals were fitted using a Fortran program called DISCRETE and two relaxation times, 49.7 ± 5.6 and 11.2 ± 2.5 μs, were determined. These relaxation times were independent of the method of myosin preparation, the method of myosin purification, the concentration of sodium pyrophosphate between 2 and 10 m M , the concentration of myosin between 0.08 and 1.59 mg/mL, and the temperature between 4.0 and 20.0°C, after correction to 20.0°C. The longer relaxation time is consistent with a rigid, linear myosin molecule. The shorter relaxation time is consistent with myosin that has a completely flexible hinge region in the myosin tail. Both relaxation times are inconsistent with the previously reported single relaxation time of myosin obtained by fitting the birefringence decay data to only 90% of the decay signal. By forcing some of the birefringence decay data in the present work to fit 90% of the decay signal with a single relaxation time, approximately the same relaxation time as previously reported was obtained.