Decoding the interaction of an imidazo-pyrimidine derivative with serum proteins: Spectroscopic, computational and structure-activity relationship analysis

Abstract

In the present article, we have tried to theoretically analyze the structure-function relationship of a novel imidazo pyrimidine derivative, IPD, and decipher its interactions with two serum proteins, BSA and HSA, spectroscopically. IPD is almost non-fluorescent in a polar environment, but its fluorescence enhancement is significant in non-polar mediums like proteins. Steady-state fluorometric investigations indicate a strong binding interaction between the probe, IPD, and serum proteins, with HSA being more strongly bound to IPD. This stronger binding affinity of the IPD–HSA complex than compared to the IPD–BSA complex was corroborated through denaturation and quenching studies, too. In silico molecular docking interactions also reveal a similar stronger binding affinity in HSA than BSA. This is attributed to the probe residing in a more hydrophobic region in HSA; thus, the π and alkyl interactions are stronger in HSA than in BSA.