Thermodynamic and structural basis of phosphorylation-induced disorder-to-order transition in the regulatory light chain of smooth muscle myosin.

ABSTRACT: We have performed molecular dynamics simulations of the phosphorylation domain (PD) of the regulatory light chain (RLC) of smooth muscle myosin, to gain insight into the thermodynamic principles governing the phosphorylation-induced disorder-to-order transition. Simulations were performed in explicit water under near-physiological conditions, starting with an ideal alpha-helix. In the absence of phosphorylation, the helical periodicity of the peptide was disrupted at residues T9-K11, while phosphorylation significantly favored the helical periodicity, in agreement with experimental data. Using the MM/PBSA approach, we calculated a relative free energy of -7.1 kcal/mol for the disorder-to-order transition. A large enthalpic decrease was compensated by a large loss of conformational entropy,

SUBMITTER: Espinoza-Fonseca LM 

PROVIDER: S-EPMC2875193 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature