Determining the atomic charge of calcium ion requires the information of its coordination geometry in an EF-hand motif.

ABSTRACT: It is challenging to parameterize the force field for calcium ions (Ca²⁺) in calcium-binding proteins because of their unique coordination chemistry that involves the surrounding atoms required for stability. In this work, we observed a wide variation in Ca²⁺ binding loop conformations of the Ca²⁺-binding protein calmodulin, which adopts the most populated ternary structures determined from the molecular dynamics simulations, followed by ab initio quantum mechanical (QM) calculations on all 12 amino acids in the loop that coordinate Ca²⁺ in aqueous solution. Ca²⁺ charges were derived by fitting to the electrostatic potential in the context of a classical or polarizable force field (PFF). We discovered that the atomic radius of Ca²

SUBMITTER: Zhang P 

PROVIDER: S-EPMC8097717 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature