Why Does the Active Form of Galactose Oxidase Possess a Diamagnetic Ground State?

Jochen Müller; Thomas Weyhermüller; Eckhard Bill; Peter Hildebrandt; Linda Ould-Moussa; Thorsten Glaser; Karl Wieghardt

doi:10.1002/(SICI)1521-3773(19980316)37:5<616::AID-ANIE616>3.0.CO;2-4

Why Does the Active Form of Galactose Oxidase Possess a Diamagnetic Ground State?

Angew Chem Int Ed Engl. 1998 Mar 16;37(5):616-619. doi: 10.1002/(SICI)1521-3773(19980316)37:5<616::AID-ANIE616>3.0.CO;2-4.

Authors

Jochen Müller¹, Thomas Weyhermüller¹, Eckhard Bill¹, Peter Hildebrandt¹, Linda Ould-Moussa¹, Thorsten Glaser¹, Karl Wieghardt¹

Affiliation

¹ Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr (Germany), Fax: +(49) 208-306-3952.

PMID: 29711069
DOI: 10.1002/(SICI)1521-3773(19980316)37:5<616::AID-ANIE616>3.0.CO;2-4

Abstract

The relative orientation of the two magnetic orbitals, the Cu^II d x 2-y 2 orbital and the half-occupied π orbital of the tyrosyl radical, is the key to answering the question in the title. The arrangement shown (Cu^II -O-C bond angle of about 130° and a dihedral angle of about 90° between the x,y plane of the Cu^II polyhedron and the tyrosyl ring plane) leads to an overlap of the orbitals, which results in a singlet ground state.

Keywords: Bioinorganic chemistry; Copper; Oxidases; Phenoxyl complexes; Radical ions.