title: Ultrafast photoinduced electron transfer in green fluorescent protein bearing a genetically encoded electron acceptor.
abstract: Electron transfer (ET) is widely used for driving the processes that underlie the chemistry of life. However, our abilities to probe electron transfer mechanisms in proteins and design redox enzymes are limited, due to the lack of methods to site-specifically insert electron acceptors into proteins in vivo. Here we describe the synthesis and genetic incorporation of 4-fluoro-3-nitrophenylalanine (FNO2Phe), which has similar reduction potentials to NAD(P)H and ferredoxin, the most important biological reductants. Through the genetic incorporation of FNO2Phe into green fluorescent protein (GFP) and femtosecond transient absorption measurement, we show that photoinduced electron transfer (PET) from the GFP chromophore to FNO2Phe occurs very fast (within 11 ps), which is comparable to that of the first electron transfer step in photosystem I, from P700* to A0. This genetically encoded, low-reduction potential unnatural amino acid (UAA) can significantly improve our ability to investigate electron transfer mechanisms in complex reductases and facilitate the design of miniature proteins that mimic their functions.
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Xiaoxuan
authors.initials: X
authors.lastname: Lv
authors.affiliation: §Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: ‡Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhou
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Hu
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Jiasong
authors.initials: J
authors.lastname: Li
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Deng
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zheng
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Gong
authors.affiliation: ‡Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Andong
authors.initials: A
authors.lastname: Xia
authors.affiliation: †Laboratory of RNA Biology and Laboratory of Quantum Biophysics, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
authors.forename: Jiangyun
authors.initials: J
authors.lastname: Wang
mesh_terms: D004579:Electron Transport; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D055668:Photochemical Processes
chemical_list: D049452:Green Fluorescent Proteins; D010649:Phenylalanine