Networks of coupled rotators: relationship between structures and internal dynamics in metal-binding proteins. Applications to apo- and holo-calbindin.

This article presents an analysis of the internal dynamics of the Ca2+-binding protein calbindin, based on the Networks of Coupled Rotators (NCRs) introduced recently. Several fundamental and practical issues raised by this approach are investigated. The roles of various parameters of the model are examined. The NCR model is shown to account for the modifications of the internal dynamics upon Ca2+ binding by calbindin. Two alternative strategies to estimate local internal effective correlation times of the protein are proposed, which offer good agreement between predictions and experiment.