Indoleamine 2,3 dioxygenase 1 immobilization on magnetic nanoparticles for screening inhibitors from coffee

In this study, a ligand fishing method was developed to screen potential indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors from coffee extracts by immobilization of IDO1 enzyme on amino-modified magnetic nanoparticles combined with UHPLC-Q-TOF-MS/MS analysis. Parameters including enzyme concentration, immobilization time, the pH of glutaraldehyde and the amount of magnetic nanoparticles were optimized. The results indicated that immobilized IDO1 could be reused 5 times and was stable during storage for 7 days. Several IDO1 ligands were captured by incubating immobilized IDO1 with coffee extract, of which 10 showed an obvious difference comparing to non-conjugated bare nanoparticles. In vitro inhibitory activity was further performed by CE analysis, in which ferulic acid and chlorogenic acid had better IDO1 inhibitory activity, with IC50 value of 113.7 & mu;M and 307.5 & mu;M. These results demonstrate that this method provides an effective platform for identifying and screening IDO1 inhibitors from natural products.

Automated summary

In this study, a ligand fishing method was developed to screen potential IDO1 inhibitors from coffee extracts using immobilized IDO1 enzyme on amino-modified magnetic nanoparticles and UHPLC-Q-TOF-MS/MS analysis. The optimized parameters included enzyme concentration, immobilization time, glutaraldehyde pH, and the amount of magnetic nanoparticles. The results showed that the immobilized IDO1 could be reused and remained stable during storage. Several IDO1 ligands were captured, with ferulic acid and chlorogenic acid exhibiting better inhibitory activity. This method provides an effective platform for identifying and screening IDO1 inhibitors from natural products.