Influence of the bound nucleotide on the molecular dynamics of actin |
| |
Authors: | G Hegyi L Szilágyi J Belágyi |
| |
Affiliation: | Department of Biochemistry, E?tv?s Loránd University, Budapest, Hungary. |
| |
Abstract: | Rotational dynamics of actin spin-labelled with maleimide probes at the reactive thiol Cys-374 were studied. Replacement of the bound nucleotide by Br8ATP in G-actin and Br8ADP 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 Vmax and K(actin) decreased significantly when the bound nucleotide of actin was Br8ADP. |
| |
Keywords: | |
|
|