title: Designing Light-Activated Charge-Separating Proteins with a Naphthoquinone Amino Acid.
abstract: The first principles design of manmade redox-protein maquettes is used to clarify the physical/chemical engineering supporting the mechanisms of natural enzymes with a view to recapitulate and surpass natural performance. Herein, we use intein-based protein semisynthesis to pair a synthetic naphthoquinone amino acid (Naq) with histidine-ligated photoactive metal-tetrapyrrole cofactors, creating a 100 μs photochemical charge separation unit akin to photosynthetic reaction centers. By using propargyl groups to protect the redox-active para-quinone during synthesis and assembly while permitting selective activation, we gain the ability to employ the quinone amino acid redox cofactor with the full set of natural amino acids in protein design. Direct anchoring of quinone to the protein backbone permits secure and adaptable control of intraprotein electron-tunneling distances and rates.
authors.affiliation: The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059 (USA).|Present address: Max Planck Institute for Developmental Biology, Tübingen, 72076 (Germany).
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Lichtenstein
authors.affiliation: The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059 (USA).
authors.forename: Chris
authors.initials: C
authors.lastname: Bialas
authors.affiliation: Department of Chemistry, St. Joseph's University, Philadelphia, PA 19131 (USA).
authors.forename: José F
authors.initials: JF
authors.lastname: Cerda
authors.affiliation: The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059 (USA).
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Fry
authors.affiliation: The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059 (USA).
authors.forename: P Leslie
authors.initials: PL
authors.lastname: Dutton
authors.affiliation: The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059 (USA). moserc@mail.med.upenn.edu.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Moser
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis / Q000737:chemistry*; D004579:Electron Transport / Q000528:radiation effects; D047668:Inteins; D008027:Light; D008958:Models, Molecular; D015394:Molecular Structure; D009285:Naphthoquinones / Q000138:chemical synthesis / Q000737:chemistry*; D055668:Photochemical Processes / Q000528:radiation effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D009285:Naphthoquinones; D045322:Photosynthetic Reaction Center Complex Proteins
keywords: amino acids; electron transfer; photosynthesis; protein engineering; quinones