For the first time, JCC-coupling constant measurement of protein across Van der Waal forces was achieved.

Protein is an important component of life and life activities, there are many non-covalent interactions in protein work together to stabilize protein structure and realize the function of protein.
, Vanderwaer's role is a force that can not be ignored.
often Van der Waal's action can be inferred from structural parameters in proteins such as the distance between side-chain groups, but quantitative measurements are difficult in scientific experiments. the detection of J-coupling constants
provides new information for the study of Vanderwaerli, and there are relevant reports in theoretical calculation, but direct experimental detection has not been realized.
a new nuclear magnetic resonance method was developed by the Protein Design Research Group of Qingdao Institute of Bioenergy and Process Research, Chinese Academy of Sciences, which realized the quantitative analysis of Van der Waal's role in protein for the first time by detecting the J-coupling constant of the protein methyl group carbon atom and other adipose side-chain carbon atoms.
research has been published in the Journal of the American Chemical Society (JACS 2018, 140: 3194.
the study, which focused on the IgG-binding protein GB3, was conducted on methyl in leucine, isoleanine and proline. 1H. Selective markers (marking other amino acids for the other amino acids) design editing the HMQC experimental pulse sequence, using its long radial relaxation time to achieve the transfer of magnetization vectors from methyl carbon atoms to fat family side chain carbon atoms (as shown), thus enabling jCC-coupling constant measurement across Vanderwaer force (values between -0.1-0.6 Hz).
further quantum mechanical calculations show that the JCC-coupled constant across the Van der Waal force is positively correlated with the exchange of mutually exclusive force components of van der Waal's force (another important Vanderwaer force component is the dispersion force).
the work for the first time to achieve the protein across Van der Waal's JCC-coupled constant measurement, and its source mechanism analysis, to prove the existence of the role of Van der Waal in protein provides direct experimental evidence, but also to understand the analysis of non-covalent effect in protein provides a new way of thinking.
the above research was conducted by Yao Lishan, a researcher in the protein design research group of Qingdao Energy Institute, and was supported by the National Natural Science Foundation of China, and some experiments were completed in the stable-state strong magnetic field experimental device of hefei Institute of Material Science, Chinese Academy of Sciences.
the paper information: Jingwen Li, s Yefei Wang, s Liaoyuan An, Jingfei Chen, and Lishan Yao. Direct Observation of CH/CH van de Waals Interactions in Proteins by NMR, JACS, 2018, 140: 3194-3197.