Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Shandong Energy Institute, Qingdao 266101, China.
Anal Chem. 2024 Sep 10;96(36):14354-14362. doi: 10.1021/acs.analchem.4c00688. Epub 2024 Aug 23.
π-Stacking, a type of noncovalent interactions involving aromatic residues, plays an important role in protein folding and function. In this work, an attempt has been made to measure CH/π and NH/π stacking interactions in a protein in cells using a combined double-mutant cycle and nuclear magnetic resonance spectroscopy method. The results show that the CH/π and NH/π stacking interactions are generally weaker in cells than those in the buffer. The transient intermolecular noncovalent interactions between the protein and the complex cellular environment may compete with and thus weaken the stacking interactions in the protein. The weakening of stacking interactions can enhance the local conformational opening of proteins in cells. This is evident from the faster rates of amide hydrogen/deuterium exchange observed in cells than in the buffer, for residues that undergo local conformational opening. This study highlights the influence of the cellular environment on π-stacking and the conformational dynamics of proteins.
π-堆积是一种涉及芳香族残基的非共价相互作用，在蛋白质折叠和功能中起着重要作用。在这项工作中，我们尝试使用双突变循环和核磁共振波谱法来测量细胞中蛋白质中的 CH/π 和 NH/π 堆积相互作用。结果表明，与缓冲液相比，细胞中 CH/π 和 NH/π 堆积相互作用通常较弱。蛋白质与复杂细胞环境之间的瞬时分子间非共价相互作用可能会竞争并因此削弱蛋白质中的堆积相互作用。堆积相互作用的减弱可以增强蛋白质在细胞中的局部构象开放性。这可以从在细胞中观察到的酰胺氢/氘交换速率比缓冲液中快，而对于经历局部构象开放的残基来说，这是显而易见的。这项研究强调了细胞环境对π-堆积和蛋白质构象动力学的影响。
