title: A simple method to engineer a protein-derived redox cofactor for catalysis.
abstract: The 6×-Histidine tag which is commonly used for purification of recombinant proteins was converted to a catalytic redox-active center by incorporation of Co(2+). Two examples of the biological activity of this engineered protein-derived cofactor are presented. After inactivation of the natural diheme cofactor of MauG, it was shown that the Co(2+)-loaded 6×His-tag could substitute for the hemes in the H2O2-driven catalysis of tryptophan tryptophylquinone biosynthesis. To further demonstrate that the Co(2+)-loaded 6×His-tag could mediate long range electron transfer, it was shown that addition of H2O2 to the Co(2+)-loaded 6×His-tagged Cu(1+) amicyanin oxidizes the copper site which is 20Å away. These results provide proof of principle for this simple method by which to introduce a catalytic redox-active site into proteins for potential applications in research and biotechnology.
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.
authors.forename: Sooim
authors.initials: S
authors.lastname: Shin
authors.affiliation: Seoul National University of Science and Technology, College of Energy and Biotechnology, Department of Optometry, Seoul, 139-743, Republic of Korea.
authors.forename: Moonsung
authors.initials: M
authors.lastname: Choi
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.
authors.forename: Heather R
authors.initials: HR
authors.lastname: Williamson
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA. Electronic address: victor.davidson@ucf.edu.
authors.forename: Victor L
authors.initials: VL
authors.lastname: Davidson
mesh_terms: D002118:Calcium / Q000737:chemistry; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry; D014364:Tryptophan / Q000096:biosynthesis
chemical_list: D011994:Recombinant Proteins; D003035:Cobalt; D014364:Tryptophan; D002118:Calcium
keywords: Bioenergetics; Biotechnology; Enzyme; Histidine tag; Protein Engineering