高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (11): 20240382.doi: 10.7503/cjcu20240382

• 研究论文 • 上一篇    下一篇

温度控制的泛素/三磷酸腺苷相互作用的电喷雾质谱研究

刘思盈1, 粟雯1,2, 周仲燕1, 杨治渝1, 裴华夫1, 何芷茹1, 王娜1,3(), 岳磊1()   

  1. 1.湖南大学生物学院,化学生物传感与化学计量学国家重点实验室,长沙 410000
    2.邵阳学院药学院,邵阳 422000
    3.湖南科技大学化学与化学工程学院,湘潭 411101
  • 收稿日期:2024-08-07 出版日期:2024-11-10 发布日期:2024-09-04
  • 通讯作者: 岳磊 E-mail:wna@hnust.edu.cn;yuelei@hnu.edu.cn
  • 作者简介:王 娜, 女, 博士, 副教授, 主要从事光谱质谱联用和气相离子化学方面的研究. E⁃mail: wna@hnust.edu.cn
    第一联系人:共同第一作者.
  • 基金资助:
    国家重点研发计划项目(批准号: 2023YFF0613400)、 国家自然科学基金(批准号: 22174037)、 湖南省自然科学联合基金(批 准号: 2023JJ50255)和长沙市自然科学基金(批准号: 202269490128)

Protein-Small Molecule Interaction Electrospray Ionization Mass Spectrometry Study of the Ubiquitin/Adenosine Triphoshate Couple over Temperature Variation

LIU Siying1, SU Wen1,2, ZHOU Zhongyan1, YANG Zhiyu1, PEI Huafu1, HE Zhiru1, WANG Na1,3(), YUE Lei1()   

  1. 1.College of Biology,State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University,Changsha 410000,China
    2.College of Pharmacy,Shaoyang University,Shaoyang 422000,China
    3.School of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411101,China
  • Received:2024-08-07 Online:2024-11-10 Published:2024-09-04
  • Contact: YUE Lei E-mail:wna@hnust.edu.cn;yuelei@hnu.edu.cn
  • Supported by:
    Supported by the National Key Research and Development Program of China(No.2023YFF0613400), the National Natural Science Foundation of China(No.22174037), the Joint Funds of Natural Science Foundation of the Hunan Province, China(No.2023JJ50255) and the Project of Natural Science Foundation of Changsha, China(No.202269490128)

摘要:

通过基于温度控制的蛋白质小分子相互作用电喷雾质谱(PSMI-ESI-MS)技术探究了模式蛋白质泛素(Ubi)与重要的生物活性小分子三磷酸腺苷(ATP)体系. 在室温条件下, 泛素和ATP以1 μmol/L∶50 μmol/L浓度比混合溶液的电喷雾质谱图和自然状态下泛素的电荷特征一致, 主要形成了+5, +6, +7电荷态下的3类峰. ATP主要和+5, +6的泛素分别形成摩尔比为1∶1和1∶2的复合物, 而+7的泛素-ATP复合物实验中相对较少, 说明低电荷态时的泛素对ATP有更强的亲合力. 通过不同浓度比泛素-ATP的质谱行为分析, 发现浓度维度上的结合状态没有显著差异, 而在不同温度的泛素及泛素-ATP复合物的电荷分布情况有明显差异. 计算得到的结合亲和力随温度的增大而增大, 说明去折叠后的泛素和ATP的相互作用增强. 通过热力学进一步分析了不同浓度ATP对泛素折叠和去折叠吉布斯自由能的影响, 发现ATP的存在增加了泛素去折叠所需的能量, 因此增强了泛素的稳定性. 根据泛素和ATP在温度维度下的电喷雾质谱分析得到了化学计量比、 结合亲和力和吉布斯自由能等多维度的信息, 为蛋白质分析, 尤其是与小分子相互作用的研究提供了参考.

关键词: 电喷雾质谱, 泛素, 三磷酸腺苷, 蛋白质小分子相互作用

Abstract:

In this paper, protein-small molecule interaction electrospray ionization mass spectrometry(PSMI-ESI-MS) was used to study a model protein, ubiquitin(Ubi), and one of the most important bioactive small molecules, adenosine triphosphate(ATP) system. At room temperature, the electrospray mass spectra of the Ubi/ATP couple at the concentration ratio of 1 μmol/L∶50 μmol/L mainly showed charge states at +5, +6, and +7, corresponding well with the charge of Ubi in native state. ATP mainly formed 1∶1 and 1∶2(molar ratio) complexes with +5 and +6 ubiquitin while complexes with +7 was much less abundant, indicating that ubiquitin in lower charge state has a stronger binding affinity for ATP. Analysis of Ubi/ATP mass spectra at different ratios showed that there was no significant difference in the binding state at the concentration dimension. However, there was a significant difference in the charge distribution of Ubi and Ubi-ATP complexes at temperature variation. The calculated binding affinity increased with increasing temperature, indicating that the interaction between Ubi and ATP was enhanced after unfolding. Furthermore, Gibbs free energy of folded and unfolded Ubi indicated that the presence of ATP increased the energy required for unfolding, thereby enhancing the stability of ubiquitin. In this study, multi-dimensional information such as stoichiometric ratio, affinity, and Gibbs free energy were obtained based on electrospray mass spectrometry analysis of ubiquitin and ATP in the temperature dimension. It provides a general strategy for subsequent studies on protein-small molecule interactions.

Key words: Electrospray ionization mass spectrometry, Ubiquitin, Adenosine triphosphate, Protein-small molecule interaction

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