Gu Meng, Zhang Jiaxu, Hase William L, Yang Li
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79401, United States.
ACS Omega. 2020 Jan 10;5(3):1463-1471. doi: 10.1021/acsomega.9b03091. eCollection 2020 Jan 28.
Arginine has significant effects on fragmentation patterns of the protonated peptide due to its high basicity guanidine tail. In this article, thermal dissociation of the singly protonated glycine-arginine dipeptide (GR-H) was investigated by performing direct dynamics simulations at different vibrational temperatures of 2000-3500 K. Fourteen principal fragmentation mechanisms containing side-chain and backbone fragmentation were found and discussed in detail. The mechanism involving partial or complete loss of a guanidino group dominates side-chain fragmentation, while backbone fragmentation mainly involves the three cleavage sites of a1-x1, a2-x0, and b1-y1. Fragmentation patterns for primary dissociation have been compared with experimental results, and the peak that was not identified by the experiment has been assigned by our simulation. Kinetic parameters for GR-H unimolecular dissociation may be determined by direct dynamics simulations, which are helpful in exploring the complex biomolecules.
由于精氨酸具有高碱性的胍基尾部，它对质子化肽的碎裂模式有显著影响。在本文中，通过在2000 - 3500 K的不同振动温度下进行直接动力学模拟，研究了单质子化甘氨酸 - 精氨酸二肽（GR-H）的热解离。发现并详细讨论了14种主要的碎裂机制，包括侧链和主链碎裂。涉及胍基部分或完全丢失的机制主导侧链碎裂，而主链碎裂主要涉及a1-x1、a2-x0和b1-y1这三个裂解位点。将一级解离的碎裂模式与实验结果进行了比较，并且通过我们的模拟确定了实验未识别的峰。GR-H单分子解离的动力学参数可通过直接动力学模拟确定，这有助于探索复杂的生物分子。
