Open AccessInfluence of the bound nucleotide on the molecular dynamics of actin
Author(s) -
HEGYI György,
SZILÁGYI László,
BELÁGYI József
Publication year - 1988
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1988.tb14193.x
Subject(s) - nucleotide , actin , myosin , electron paramagnetic resonance , rotational correlation time , chemistry , maleimide , tropomyosin , biophysics , biochemistry , biology , nuclear magnetic resonance , physics , gene , polymer chemistry
Rotational dynamics of actin spin‐labelled with maleimide probes at the reactive thiol Cys‐374 were studied. Replacement of the bound nucleotide by Br 8 ATP in G‐actin and Br 8 ADP in F‐actin causes significant increase of the rotational correlation time of the spin probe, indicating reduced motion in both G and F‐actin. The orientation dependence of the electron paramagnetic resonance spectra in oriented F‐actin filaments revealed an altered molecular order of the probe when the nucleotide was a Br‐substituted one. The bound nucleotide affects the myosin S1 ATPase activation by actin; both V max , and K actin decreased significantly when the bound nucleotide of actin was Br 8 ADP.