Characterization of binding interactions between selected phenylpropanoid glycosides and trypsin

Area of Science:

• Biochemistry
• Pharmacology
• Natural Products Chemistry

Background:

• Phenylpropanoid glycosides (PPGs) are a class of bioactive polyphenols found in various plants.
• These compounds possess diverse pharmacological properties, warranting investigation into their molecular interactions.
• Trypsin is a key digestive enzyme with implications in various physiological and pathological processes.

Purpose of the Study:

• To investigate the inhibitory effects of four selected PPGs on trypsin activity.
• To elucidate the interaction mechanisms between these PPGs and trypsin using biophysical and computational methods.

Main Methods:

• Enzyme inhibition assays were performed to quantify the inhibitory effects of PPGs on trypsin.
• Spectroscopic techniques (e.g., fluorescence, UV-Vis) were employed to study PPG-trypsin interactions.
• Molecular docking simulations were utilized to predict binding modes and affinities.

Main Results:

• All four tested PPGs exhibited inhibitory effects against trypsin.
• The inhibitory order was determined as: acteoside > syringalide A 3'-α-l-rhamnopyranoside > lipedoside A-I > osmanthuside B.
• Binding affinity and inhibitory potency increased with the number of phenolic hydroxyl groups, particularly those on the A ring, suggesting a significant role in hydrogen bonding interactions.

Conclusions:

• PPGs interact with trypsin, leading to conformational changes and enzyme inhibition.
• The number and position of phenolic hydroxyl groups are critical determinants of PPGs' binding affinity and inhibitory efficacy against trypsin.
• Hydrogen bonding plays a crucial role in the observed PPG-trypsin interactions.