title: QM/MM calculation of protein magnetic shielding tensors with generalized hybrid-orbital method: a GIAO approach.
abstract: A method to compute magnetic shielding tensors with generalized hybrid-orbital (GHO) QM/MM scheme is developed at the levels of Hartree-Fock and second-order Møller-Plesset perturbation theory using gauge-including atomic orbitals. A feature of the GHO method is utilized to ensure gauge-origin independency of GHO shielding tensors in a simple way. The benchmark calculations indicate that the GHO method reproduced full-QM shielding constants nearly quantitatively for atoms not directly coupled to the GHO linking atoms. As an application to a realistic protein, carbon chemical shifts are calculated for the retinal chromophore in visual rhodopsin.
authors.affiliation: Graduate School of System Informatics, Kobe University, Kobe 657-8501, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Akinaga
authors.forename: Jaewoon
authors.initials: J
authors.lastname: Jung
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ten-no
mesh_terms: D004151:Dipeptides / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D011487:Protein Conformation; D011789:Quantum Theory; D012243:Rhodopsin / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D012243:Rhodopsin