Related Experiment Video
Updated: Jan 26, 2026
A Direct Force Probe for Measuring Mechanical Integration Between the Nucleus and the Cytoskeleton
Published on: July 29, 2018
Integrated multi-spectroscopic and molecular modelling techniques to probe the interaction mechanism between
Hongjin Tang1, Fei Ma2, Dongsheng Zhao3
1College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu 241000, PR China.
Abstract:
α-Glucosidase (AG) is an important drug target for the treatment of type 2 diabetes mellitus in humans due to the potential effect of down regulating glucose absorption in patients. In our previous study, salvianolic acid A (SAA) was found to exhibit potent AG inhibitory activity, whereas the interaction mechanism was still ambiguous. Herein, the interaction mechanism of SAA and AG was investigated by multi-spectroscopic methods along with molecular docking. As a result, it was found that SAA reversibly inhibited AG in a competitive manner with IC50 of 16.44 ± 0.18 μM, and the inhibition belonged to a multi-phase kinetics process with a first-order reaction. The intrinsic fluorescence of AG could be strongly quenched by SAA through a static quenching mechanism. The negative Gibbs free energy change and positive values of enthalpy and entropy change revealed that the binding of SAA to AG was spontaneous and dominated mainly by hydrophobic interactions, and only a single binding site was determined for them. Analysis of synchronous fluorescence, ANS-binding fluorescence, circular dichroism and Fourier transform infrared spectra suggested that the binding of SAA to AG induced rearrangement and conformational changes of the enzyme. Besides, further molecular modelling validated that SAA could bind to the active domain and prevent the entrance of substrate, resulting in the inhibition of AG activity. These findings provide new insights into understanding the interaction mechanism of SAA on AG.
Related Concept Videos
01:19Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are...
03:05Acid Strength and Molecular Structure
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
02:00Molecular Models
02:34Molecular Structure and Acidity
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
01:21Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
01:14α-Halogenation of Carboxylic Acid Derivatives: Overview