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A jump in an Arrhenius plot can be the consequence of a phase transition
Author(s) -
Biosca J.A.,
Travers F.,
Barman T.E.
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)80151-3
Subject(s) - arrhenius plot , arrhenius equation , thermodynamics , chemistry , temperature jump , activation energy , kinetics , jump , phase (matter) , phase transition , myosin , ethylene glycol , crystallography , physics , biochemistry , organic chemistry , quantum mechanics
The temperature dependence of the kinetics of the binding of ATP to myosin subfragment−1 was studied by an ATP chase technique in a rapid−flow—quench apparatus: A temperature range of 30°C to −15°C was obtained with ethylene glycol as antifreeze. The Arrhenius plot of k 2 is discontinuous with a jump at 12°C. Above the jump Δ H ≠ = 9.5 kcal/mol, below Δ H ≠ = 28.5 kcal/mol. Few such Arrhenius plots are recorded in the literature but they are predicted from theory. Thus, we explain our results as a phase change of the subfragment 1−ATP system at 12°C. This is in agreement with certain structural studies.