Photo-CIDNP-Enhanced 19F NMR for Rapid Protein Conformation and Ligand Binding Analysis
Zhaofei Chai, Weixuan Wang, Qiong Wu, Xiaoli Liu, Jiawen Chen, Yanqi Xu, Guohua Xu, Xiuchao Zhao, Xin Zhou, Ling Jiang, Maili Liu, Conggang LiAbstract
19F NMR spectroscopy is a powerful probe of protein conformation and dynamics but is intrinsically limited by low sensitivity common to other NMR techniques. Here, we integrate photochemically induced dynamic nuclear polarization (photo-CIDNP) with genetically encoded 19F labels to enhance sensitivity by up to 220-fold, enabling the detection of 100 nM protein within 6.5 min. This approach employs commercially available, cost-effective 19F-labeled amino acid analogues and is broadly applicable to proteins ranging from 6.6 to 54.2 kDa. It allows rapid analysis of conformational changes and ligand binding in the low-micromolar range within minutes. Notably, it can readily characterize interactions with dissociation constants below 5 μM, which are challenging to access using conventional NMR. The combination of photo-CIDNP-induced sensitivity enhancement with the environmental responsiveness of 19F NMR establishes a practical platform for protein structural and interaction studies.