Influence of protein environment on the electron paramagnetic resonance properties of flavoprotein radicals: a QM/MM study.

The neutral and anionic semiquinone radicals of the flavin adenine dinucleotide (FAD) cofactor noncovalently bound in glucose oxidase from A. niger are examined with the aid of QM/MM molecular modeling methods, enabling complete inclusion of the protein environment. Recently, the electron paramagnetic resonance (EPR) characteristics, the anisotropic g tensor and all the significant hyperfine couplings, of these flavoprotein radicals were determined at high resolution (J.

Magnetic linear response properties calculations with the Gaussian and augmented-plane-wave method.

We introduce a method for the all-electron calculation of the NMR chemical shifts and the EPR g tensor using the Gaussian and augmented-plane-wave method. The presented approach is based on the generalized density functional perturbation theory. The method is validated by comparison with other theoretical methods for a selection of small molecules.

Evidence for a Grotthuss-like mechanism in the formation of the rhamnose alkoxy radical based on periodic DFT calculations.

Pauwels, E., Declerck, R., Van Speybroeck, V.