[Study on interaction of caffeine with myoglobin by fluorescence spectroscopy].
The interaction of caffein and myoglobin was investigated by fluorescence spectroscopy and synchronous fluorescence spectroscopy. The intrinsic fluorescence of myoglobin was significantly quenched by caffein under the physiological condition (pH 7.4). The results indicated that caffeine was capable of binding with myoglobin to form a 1:1 complex and the quenching mechanism of myoglobin affected by caffeine was shown to be a static quenching procedure by calculating quenching constant, binding sites and binding constant. According to the thermodynamic parameters, the main binding force of the interaction is electrostatic force and hydrophobic force. The change in the micro-circumstance of aminos of myoglobin was analyzed by synchronous fluorescence spectrometry. The result indicated that caffeine can change the conformation of the protein, leading to the change in the micro-environment of tryptophane and tyrosine residues from hydrophobic environment to hydrophilic environment to different extent.
Huang
He-Yong
HY
Analysis and Testing Center, Nanjing Normal University, Nanjing 210097, China. hhynjnu@126.com
Gu
Xiao-Tian
XT
Ding
Yan
Y
Zhou
Jia-Hong
JH
Feng
Yu-Ying
YY
D001665:Binding Sites; D002110:Caffeine; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008968:Molecular Conformation; D009211:Myoglobin; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D009211:Myoglobin; D002110:Caffeine