Interaction of inosine with human serum albumin as determined by NMR relaxation data and fluorescence methodology

Understanding the binding mechanisms of drug–protein interactions is a crucial factor in determining the pharmacokinetics and pharmacodynamics of a drug. In this study, the binding affinity of inosine toward the HSA, as well as the dynamic properties of HSA-inosine complexes was obtained from applying NMR methodology. The changes in proton selective and non-selective relaxation rates suggested that inosine interacts with HSA. The values of normalized affinity indexes and equilibrium constant K provided information about the binding strength, which were in accordance with fluorescence result. The detailed binding mechanisms were obtained through fluorescence method , and the binding mode was displayed using Discovery Studio. Circular dichroism data further confirmed the secondary structure changes in HSA upon inosine addition. This study provided insights on the interactions between inosine and HSA.