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The limiting rate of the ATP‐mediated dissociation of actin from rabbit skeletal muscle myosin subfragment 1
Author(s) -
Millar N.C.,
Geeves M.A.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80954-5
Subject(s) - dissociation (chemistry) , myosin , chemistry , actin , ethylene glycol , biophysics , arrhenius equation , reaction rate constant , isomerization , adenosine triphosphate , kinetics , crystallography , biochemistry , biology , organic chemistry , activation energy , catalysis , physics , quantum mechanics
The ATP‐induced dissociation of actoS1 has been studied at temperatures between −10°C and +30°C in a stopped‐flow apparatus using ethylene glycol as antifreeze. At temperatures at and below 0°C the observed rate of the dissociation of actin shows a hyperbolic dependence on ATP concentration. This is interpreted in terms of a rapid binding of ATP followed by an isomerisation of the ternary complex which results in actin dissociation. Ethylene glycol weakens ATP binding but the rate of the isomerisation is unaffected. The second order rate constant for the dissociation shows a break in the Arrhenius plot.