Turkish Journal of Biochemistry, cilt.39, sa.4, ss.463-471, 2014 (SCI-Expanded)
Objective: In this study the inhibitory effect of E. arvense extract on trypsin activity and the effect of trypsin on E. arvense extract were studied. In addition the nature of the interaction between the extract and trypsin was investigated. Methods: The inhibitory effect ethanol extract of E. arvense on trypsin activity was determined using trypsin enzyme assay. The structural effects of the extract-trypsin interaction for the extract were analyzed by FTIR. Finally, the HPLC analyses were carried out to analyze the individual components of the extract and the supernatant and soluble precipitate phases. Results: E. arvense extract was found to decrease total percent activity of trypsin to 5% in 24 hour at 24 °C. FTIR analyses indicated that the interaction between trypsin and E. arvense extract caused changes in the structure and hydrogen bonding behavior and composition of the extract proteins. These interactions also caused the extract lipids to accumulate in the insoluble precipitate phase. Most of the phenolics remained in the supernatant phase enhancing the inactivation of trypsin. However, the precipitated compounds were shown to be of apolar in nature as shown in the HPLC chromatograms. Conclusion: The methods that were used showed that the high phenolic content of E. arvense was the main reason for the inhibition of trypsin enzyme activity by denaturing the enzyme.