Electron transfer pathways and spin–spin interactions in Mo- and Cu-containing oxidoreductases

Abstract

Oxidoreductases containing transition metal ions are widespread in nature and are essential for living organisms. In these enzymes, transition metal ions are present either as mononuclear centers or organized into clusters, accomplishing two main roles. One is to be the core of active sites where the substrate is converted into product, and the other is to serve as electron transfer centers. Oxidoreductases containing multiple redox cofactors bind both the substrate and an external electron donor/acceptor at distant protein sites for them to exchange the electrons involved in the redox reaction. Intra-protein electron transfer occurs through specific pathways that link distant metal cofactors, which may additionally be magnetically coupled. Here we review the current understanding on the molecular properties of these long chemical pathways involved in metal coordination, intra − protein electron transfer processes, and transmitting magnetic interactions in Mo- and Cu-containing oxidoreductases.