title: Combining a Nitrogenase Scaffold and a Synthetic Compound into an Artificial Enzyme.
abstract: Nitrogenase catalyzes substrate reduction at its cofactor center ([(Cit)MoFe7S9C](n-); designated M-cluster). Here, we report the formation of an artificial, nitrogenase-mimicking enzyme upon insertion of a synthetic model complex ([Fe6S9(SEt)2](4-); designated Fe6(RHH)) into the catalytic component of nitrogenase (designated NifDK(apo)). Two Fe6(RHH) clusters were inserted into NifDK(apo), rendering the conformation of the resultant protein (designated NifDK(Fe)) similar to the one upon insertion of native M-clusters. NifDK(Fe) can work together with the reductase component of nitrogenase to reduce C2H2 in an ATP-dependent reaction. It can also act as an enzyme on its own in the presence of Eu(II)DTPA, displaying a strong activity in C2H2 reduction while demonstrating an ability to reduce CN(-) to C1-C3 hydrocarbons in an ATP-independent manner. The successful outcome of this work provides the proof of concept and underlying principles for continued search of novel enzymatic activities based on this approach.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900 (USA).
authors.forename: Kazuki
authors.initials: K
authors.lastname: Tanifuji
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900 (USA).
authors.forename: Chi Chung
authors.initials: CC
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Graduate School of Science and Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan).
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ohki
authors.affiliation: Department of Chemistry, Graduate School of Science and Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan).
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tatsumi
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900 (USA). yilinh@uci.edu.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900 (USA). mribbe@uci.edu.|Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025 (USA). mribbe@uci.edu.
authors.forename: Markus W
authors.initials: MW
authors.lastname: Ribbe
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D006838:Hydrocarbons / Q000737:chemistry / Q000378:metabolism; D058085:Iron Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009591:Nitrogenase / Q000737:chemistry* / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D006838:Hydrocarbons; D058085:Iron Compounds; D000255:Adenosine Triphosphate; D009591:Nitrogenase; D003545:Cysteine
keywords: CC coupling; artificial enzyme; hydrocarbon; nitrogenase; synthetic compound