title: Ru(II)-diimine functionalized metalloproteins: From electron transfer studies to light-driven biocatalysis.
abstract: The unique photochemical properties of Ru(II)-diimine complexes have helped initiate a series of seminal electron transfer studies in metalloenzymes. It has thus been possible to experimentally determine rate constants for long-range electron transfers. These studies have laid the foundation for the investigation of reactive intermediates in heme proteins and for the design of light-activated biocatalysts. Various metalloenzymes such as hydrogenase, carbon monoxide dehydrogenase, nitrogenase, laccase and cytochrome P450 BM3 have been functionalized with Ru(II)-diimine complexes. Upon visible light-excitation, these photosensitized metalloproteins are capable of sustaining photocatalytic activity to reduce small molecules such as protons, acetylene, hydrogen cyanide and carbon monoxide or activate molecular dioxygen to produce hydroxylated products. The Ru(II)-diimine photosensitizers are hence able to deliver multiple electrons to metalloenzymes buried active sites, circumventing the need for the natural redox partners. In this review, we will highlight the key achievements of the light-driven biocatalysts, which stem from the extensive electron transfer investigations. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
authors.affiliation: San José State University, Department of Chemistry, One Washington Square, San José, CA 95192-0101, United States.
authors.forename: Quan
authors.initials: Q
authors.lastname: Lam
authors.affiliation: San José State University, Department of Chemistry, One Washington Square, San José, CA 95192-0101, United States.
authors.forename: Mallory
authors.initials: M
authors.lastname: Kato
authors.affiliation: San José State University, Department of Chemistry, One Washington Square, San José, CA 95192-0101, United States. Electronic address: lionel.cheruzel@sjsu.edu.
authors.forename: Lionel
authors.initials: L
authors.lastname: Cheruzel
mesh_terms: D000818:Animals; D002384:Catalysis; D004579:Electron Transport / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics; D006801:Humans; D007097:Imines / Q000737:chemistry* / Q000378:metabolism; D008667:Metalloproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011485:Protein Binding / Q000235:genetics; D015202:Protein Engineering / Q000379:methods*; D012428:Ruthenium / Q000737:chemistry* / Q000378:metabolism
chemical_list: D007097:Imines; D008667:Metalloproteins; D012428:Ruthenium
keywords: Electron transfer studies; Light-driven biocatalysis; Ruthenium photosensitizers