<i>In vivo</i> Incorporation of Unnatural Amino Acids to Probe Structure, Dynamics, and Ligand Binding in a Large Protein by Nuclear Magnetic Resonance Spectroscopy
作者:Susan E. Cellitti、David H. Jones、Leanna Lagpacan、Xueshi Hao、Qiong Zhang、Huiyong Hu、Scott M. Brittain、Achim Brinker、Jeremy Caldwell、Badry Bursulaya、Glen Spraggon、Ansgar Brock、Youngha Ryu、Tetsuo Uno、Peter G. Schultz、Bernhard H. Geierstanger
DOI:10.1021/ja801602q
日期:2008.7.1
UV-cleavage of the nitrobenzyl-photocage from oNBTyr re-established binding. These data suggest not onlyrobust methods for using unnatural amino acids to study large proteins by NMR but also establish a new avenue for the site-specific labeling of proteins at individual residues without altering the protein sequence, a feat that can currently not be accomplished with any other method.
recover to natural tyrosine after UV-photocleavage was greatly improved from 20% to 81% by using 2-nitrobenzyl bromide as the nucleophilic reagent. Through genetically introducing 15N-oNBY and consequent photo-cleavage, the site-specific 15N-Tyr NMR analysis of plant ABA (abscisic acid) receptor PYL10 was implemented without any residue variation. This isotope labelling of tyrosine onto protein backbone
Vibrational spectra contain unique information on protein structure and dynamics. However, this information is often obscured by spectral congestion, and site-selective information is not available. In principle, sites of interest can be spectrally identified by isotope shifts, but site-specific isotopelabeling of proteins is today possible only for favorable amino acids or with prohibitively low
振动光谱包含有关蛋白质结构和动力学的独特信息。然而,该信息通常被频谱拥塞所掩盖,并且站点选择性信息不可用。原则上,感兴趣的位点可以通过同位素位移进行光谱识别,但如今仅对有利的氨基酸或产量低得令人望而却步的蛋白质的位点特异性同位素标记是可能的。在这里,我们提出了一种有效的无细胞表达系统,用于将任何同位素标记的氨基酸定点掺入蛋白质中。我们从 100 mL 无细胞反应提取物中合成了 1.6 mg 绿色荧光蛋白和同位素标记的酪氨酸。我们明确地确定了时间分辨红外吸收光谱指纹区域中酪氨酸的光谱特征。动力学分析证实了光激发和质子转移之间存在一个持续时间为 3 ps 的中间状态。我们的方法将蛋白质的振动光谱提升到更高水平的结构特异性。