Key result
Actin filaments assembled from ADP-actin monomers exhibited substantially greater inter-monomer flexibility and smaller fluorescence intensity at Cys(374) compared to those from ATP-actin monomers.
Actin filaments polymerized from ADP-actin monomers exhibit greater inter-monomer flexibility compared to those from ATP-actin monomers, reflecting nucleotide-induced conformational differences.
Nucleotide effects on actin flexibility extend biophysical models; leaves open relevance to cardiac cytoskeletal function.
Conformational and dynamic properties of actin filaments polymerized from ATP- or ADP-actin monomers were compared by using fluorescence spectroscopic methods. The fluorescence intensity of IAEDANS attached to the Cys(374) residue of actin was smaller in filaments from ADP-actin than in filaments from ATP-actin monomers, which reflected a nucleotide-induced conformational difference in subdomain 1 of the monomer. Radial coordinate calculations revealed that this conformational difference did not modify the distance of Cys(374) from the longitudinal filament axis. Temperature-dependent fluorescence resonance energy transfer measurements between donor and acceptor molecules on Cys(374) of neighboring actin protomers revealed that the inter-monomer flexibility of filaments assembled from ADP-actin monomers were substantially greater than the one of filaments from ATP-actin monomers. Flexibility was reduced by phalloidin in both types of filaments.
No takes yet. Share an insight, caveat, or question.
Nyitrai et al. (2000) studied this question. ADP-actin monomers vs. ATP-actin monomers was evaluated on Conformational and dynamic properties (fluorescence intensity and inter-monomer flexibility). Actin filaments assembled from ADP-actin monomers exhibited substantially greater inter-monomer flexibility and smaller fluorescence intensity at Cys(374) compared to those from ATP-actin monomers.
Synapse has enriched 2 closely related papers on similar clinical questions. Consider them for comparative context: