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Interactions between α-amylase and an acidic branched polysaccharide from green tea
- Source :
- International journal of biological macromolecules. 94
- Publication Year :
- 2016
-
Abstract
- To understand the mechanism responsible for the α-amylase inhibitory activity of tea polysaccharides, the interaction between α-amylase and an acidic branched tea polysaccharide (TPSA) was investigated using fluorescence spectroscopy and resonance light scattering analysis. TPSA, exhibiting inhibitory activity towards α-amylase (the maximum inhibition percentage of 65%), was isolated from green tea (Camellia sinensis) and characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and gas chromatography. Synchronous fluorescence spectroscopy revealed that the binding interaction between the tryptophan residues of α-amylase and TPSA was predominant. Based on the fluorescence quenching effect of tryptophan residues induced by TPSA, the binding constants between α-amylase and TPSA were determined to be 18.6×106, 8.0×106 and 4.6×106 L·mol-1 at 20, 30 and 37°C, respectively. The calculated Gibbs free-energy changes were negative, indicating that the bonding interaction was a spontaneous process. The enthalpy and the entropy changes were -62.13 KJ·mol-1 and -0.0728 KJ·mol-1·K-1, suggesting that hydrogen bonding interactions might play a major role in the binding process. The formation of an α-amylase/TPSA complex was evidenced by fluorescence quenching and resonance light scattering analysis, and this complex could be the main contributor to the α-amylase inhibitory activity of TPSA.
- Subjects :
- Stereochemistry
Swine
02 engineering and technology
010402 general chemistry
Photochemistry
Polysaccharide
01 natural sciences
Biochemistry
Fluorescence spectroscopy
Camellia sinensis
Structural Biology
Polysaccharides
Animals
Amylase
Fourier transform infrared spectroscopy
Enzyme Inhibitors
Spectroscopy
Molecular Biology
Pancreas
chemistry.chemical_classification
biology
Tea
Chemistry
Hydrogen bond
Tryptophan
Hydrogen Bonding
General Medicine
Nuclear magnetic resonance spectroscopy
Hydrogen-Ion Concentration
021001 nanoscience & nanotechnology
0104 chemical sciences
Kinetics
biology.protein
Thermodynamics
alpha-Amylases
0210 nano-technology
Protein Binding
Subjects
Details
- ISSN :
- 18790003
- Volume :
- 94
- Database :
- OpenAIRE
- Journal :
- International journal of biological macromolecules
- Accession number :
- edsair.doi.dedup.....68b77de6328946956c8b140f2a0e0853