Yapici Ipek, Lee Kin Sing Stephen, Berbasova Tetyana, Nosrati Meisam, Jia Xiaofei, Vasileiou Chrysoula, Wang Wenjing, Santos Elizabeth M, Geiger James H, Borhan Babak
Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.
J Am Chem Soc. 2015 Jan 28;137(3):1073-80. doi: 10.1021/ja506376j. Epub 2015 Jan 14.
Protein reengineering of cellular retinoic acid binding protein II (CRABPII) has yielded a genetically addressable system, capable of binding a profluorophoric chromophore that results in fluorescent protein/chromophore complexes. These complexes exhibit far-red emission, with high quantum efficiencies and brightness and also exhibit excellent pH stability spanning the range of 2-11. In the course of this study, it became evident that single mutations of L121E and R59W were most effective in improving the fluorescent characteristics of CRABPII mutants as well as the kinetics of complex formation. The readily crystallizable nature of these proteins was invaluable to provide clues for the observed spectroscopic behavior that results from single mutation of key residues.
对细胞视黄酸结合蛋白II（CRABPII）进行蛋白质改造，得到了一种基因可寻址系统，该系统能够结合一种前荧光发色团，形成荧光蛋白/发色团复合物。这些复合物发出远红光，具有高量子效率和亮度，并且在2-11的pH范围内表现出优异的稳定性。在本研究过程中，很明显L121E和R59W的单点突变在改善CRABPII突变体的荧光特性以及复合物形成动力学方面最为有效。这些蛋白质易于结晶的特性对于为关键残基单点突变所观察到的光谱行为提供线索非常宝贵。
