Probing the binding of trypsin to glutathione-stabilized gold nanoparticles in aqueous solution.
We investigate the interaction of trypsin with glutathione-stabilized Au nanoparticles (NPs) using fluorescence, synchronous fluorescence and ultraviolet (UV) absorption spectroscopy. We find that trypsin binds strongly to the Au NPs with a static quenching mechanism, and that the interaction is characteristic of positive cooperative binding. Furthermore, we determine the binding constants and the thermodynamic parameters, which suggest that the main binding forces between the glutathione-stabilized Au NPs and trypsin are electrostatic interactions and hydrogen bonding. Analysis of UV-vis absorption spectra suggests that aggregation of the Au NPs occurs in the trypsin/Au NPs system, which significantly alters the conformation of the protein.
Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, PR China. Electronic address: wanggongke@126.com.
Gongke
G
Wang
School of Computer and Information Engineering, Henan Normal University, Xinxiang, Henan 453007, PR China.
Xingbing
X
Liu
Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, PR China.
Changling
C
Yan
Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, PR China.
Guangyue
G
Bai
Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, PR China.
Yan
Y
Lu
D005978:Glutathione / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D012996:Solutions; D013816:Thermodynamics; D014357:Trypsin / Q000737:chemistry*; D014867:Water
D012996:Solutions; D014867:Water; D006046:Gold; D014357:Trypsin; D005978:Glutathione
Au nanoparticles; Cooperative binding; Fluorescence quenching; Interaction; Trypsin