湖北医药学院学报2026，Vol.45Issue(4)：414-418,434,6.DOI:10.13819/j.issn.2096-708X.2026.04.002
近红外荧光蛋白 mNeptune684 的结晶与结构解析
Crystallization and Structural Analysis of Near-Infrared Fluorescent Protein mNeptune684
摘要
Abstract
Objective To establish a purification and crystallization system for the near-infrared fluorescent protein mNep-tune684,determine its high-resolution structure,and elucidate the mechanism for its spectral red shift,to provide a struc-tural foundation for the directed evolution of near-infrared fluorescent proteins.Methods mNeptune684 and its homologous proteins were purified using nickel affinity chromatography combined with size-exclusion chromatography.Crystallization conditions were screened via the sitting-drop and hanging-drop vapor diffusion methods.The structure was determined by X-ray single-crystal diffraction,and the red-shift mechanism was analyzed.Results High-quality single crystals of mNep-tune684 were obtained under 0.2 mol/L lithium chloride and 20%w/v polyethylene glycol 3350.The structure was solved to 2.0 resolution and belonged to space group P21.A synergistic hydrogen-bonding network involving Asn143 and Asn158 extended the conjugated plane of the chromophore,and secondary structural transitions of several residues collec-tively resulted in a 34 nm red shift in the emission wavelength.Conclusion A crystallization system for mNeptune684 is successfully established,and the key mechanism for its spectral red shift is clarified,providing structural targets for the ra-tional design and directed evolution of near-infrared fluorescent proteins.关键词
近红外荧光蛋白/mNeptune684/蛋白质结晶/X 射线单晶衍射/晶体结构Key words
Near-infrared fluorescent protein/mNeptune684/Protein crystallization/X-ray single-crystal diffraction/Crystal structure引用本文复制引用
袁也..近红外荧光蛋白 mNeptune684 的结晶与结构解析[J].湖北医药学院学报,2026,45(4):414-418,434,6.基金项目
中国科学院重点部署项目(KJZD-EW-TZ-L04) （KJZD-EW-TZ-L04）
