Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (03): 397-404.DOI: 10.6023/A12110904 Previous Articles     Next Articles

Article

气相中环糊精与甘氨酰-苯丙氨酰-苯丙氨酸和甘氨酸三肽非共价复合物的质谱研究

何小丹, 许崇晟, 储艳秋, 丁传凡   

  1. 复旦大学化学系 上海市分子催化和功能材料重点实验室 上海 200433
  • 收稿日期:2012-11-12 出版日期:2013-03-14 发布日期:2013-01-21
  • 通讯作者: 丁传凡 E-mail:cfding@fudan.edu.cn
  • 基金资助:

    项目受国家科技支撑计划(No.2009BAK60B03)资助.

Investigation on Non-Covalent Complexes of Cyclodextrins with GGG and GFF Tripeptides in Gas Phase by Mass Spectrometry

He Xiaodan, Xu Chongsheng, Chu Yanqiu, Ding Chuanfan   

  1. Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200433
  • Received:2012-11-12 Online:2013-03-14 Published:2013-01-21
  • Supported by:

    Project supported by the National Key Technology R&D Program of China (No. 2009BAK60B03).

To investigate the non-covalent interaction between α-, β-, γ-cyclodextrins and peptides, a stoichiometry of α-, β-, γ-cyclodextrins (CD) with GGG (Gly-Gly-Gly) or GFF (Gly-Phe-Phe) was mixed respectively, and then incubated at room temperature for 12 h to reach the equilibrium. In positive mode, the electrospray ionization mass spectrometry (ESI-MS) results indicated that α-, β-, γ-CD with GGG or GFF could form non-covalent complexes, respectively. The binding of cyclodextrins with GGG or GFF was further confirmed by collision induced dissociation (CID) in a tandem mass spectrometer. The formation constants of six complexes (GGG+CD and GFF+CD) were determined by mass spectrometric titration. The results showed the formation constants for both GGG's and GFF's complexes increased according to the order γ-CD, β-CD, α-CD. The formation constants Kst values for GGG complexes with α-CD, β-CD or γ-CD are 2799.96, 2528.73, 1697.11 L·mol-1, respectively. While the formation constants Kst values for GFF complexes with α-CD, β-CD or γ-CD are 2773.94, 2134.03, 1330.68 L·mol-1 respectively. For α-CD, β-CD or γ-CD, the Kst values of GFF complexes containing aromatic group are smaller than those of GGG complexes only containing aliphatic group. The main reason is that in gas phase, with the weakening of hydrophobic force, Van der Waals force plays an important role in the conjugation process of GFF with CD, the coordinating group of GFF is still phenyl group. While in GGG's complexes, the hydrogen bond dominates in the conjugation process. Our convincing results from the formation constants provides a new evidence, indicating that although the conformations for GFF+CD complexes change slightly when the analysts transfer from solution to gas phase, the phenyl group still takes part in coordinating.

Key words: cyclodextrins, GGG and GFF tripeptide, non-covalent complex, mass spectrometry, formation constants