Johnson Philip J M, Koziol Klemens L, Hamm Peter
Department of Chemistry, University of Zurich , Winterthurerstr. 190, 8057 Zurich, Switzerland.
J Phys Chem Lett. 2017 May 18;8(10):2280-2284. doi: 10.1021/acs.jpclett.7b00742. Epub 2017 May 8.
Azidohomoalanine (Aha) is an unnatural amino acid containing an infrared active azido side chain group that can, through frequency shifts of the azido stretch vibration, act as a probe of local structure. To realize the potential of such structural probes for protein science, we have developed a two-dimensional infrared spectrometer employing fast mechanical scanning and intrinsic phasing of the resulting spectra, leading to a lower sensitivity limit of ∼100 μOD level samples. Using this approach, we quantify the biomolecular recognition between a PDZ2 domain and two Aha-mutated peptides. It is shown that this method can distinguish different binding modes and that the energetics of binding can be determined.
叠氮高丙氨酸（Aha）是一种非天然氨基酸，含有一个红外活性叠氮侧链基团，该基团可通过叠氮伸缩振动的频率变化，作为局部结构的探针。为了实现此类结构探针在蛋白质科学中的潜力，我们开发了一种二维红外光谱仪，采用快速机械扫描和所得光谱的固有相位调整，使灵敏度下限达到约100 μOD水平的样品。使用这种方法，我们定量了PDZ2结构域与两种Aha突变肽之间的生物分子识别。结果表明该方法可以区分不同的结合模式，并且可以确定结合能。
