title: The S28H mutation on mNeptune generates a brighter near-infrared monomeric fluorescent protein with improved quantum yield and pH-stability.
abstract: For living deep-tissue imaging, the optical window favorable for light penetration is in near-infrared wavelengths, which requires fluorescent proteins with emission spectra in the near-infrared region. Here, we report that a single mutant Ser28His of mNeptune with a near-infrared (≥650 nm) emission maxima of 652 nm is found to improve the brightness, photostability, and pH stability when compared with its parental protein mNeptune, while it remains as a monomer, demonstrating that there is still plenty of room to improve the performance of the existing near infrared fluorescence proteins by directed evolution.
authors: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Zhao-Yang
authors: ZY
authors: Li
authors: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors: Dian-Bing
authors: DB
authors: Wang
authors: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors: Zhi-Ping
authors: ZP
authors: Zhang
authors: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors: Li-Jun
authors: LJ
authors: Bi
authors: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors: Zong-Qiang
authors: ZQ
authors: Cui
authors: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors: Jiao-Yu
authors: JY
authors: Deng
authors: University of Chinese Academy of Sciences, Beijing 100049, China National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China zhangxe@sun5.ibp.ac.cn.
authors: Xian-En
authors: XE
authors: Zhang
mesh_terms: D001483:Base Sequence; D002850:Chromatography, Gel; D017931:DNA Primers; D006863:Hydrogen-Ion Concentration; D008164:Luminescent Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D009154:Mutation; D011789:Quantum Theory; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D017931:DNA Primers; D008164:Luminescent Proteins
keywords: brightness; deep-tissue imaging; mNeptune; near-infrared; photostability