Recreational drugs 25I-NBOH and 25I-NBOMe bind to both Sudlow's sites I and II of human serum albumin (HSA): biophysical and molecular modeling studies

Abstract

Experimental, biophysical, and molecular modelling studies between 25I-NBOH and 25I-NBOMe with human serum albumin (HSA) have indicated that these recreational drugs simultaneously bind to site I and II of the protein, with 25I-NBOMe showing a greater affinity for the transport protein, and that both compounds were able to perturb the native structure of HSA. The 25I-NBOH and 25I-NBOMe drugs spontaneously interact with protein (ΔG < 0), and with the complex formation in the ground state (static quenching). Preferred forces in the interaction process were determined as hydrogen bonding and van der Waals forces. From ¹H NMR studies, it was possible to determine the epitope of the molecules, as these and other results agree with the theoretical molecular docking. Overall, our results suggest that the interaction between 25I-NBOH and 25I-NBOMe with HSA can affect its distribution in the body and cause harmful effects, resulting from conformational changes in the protein which can affect its function from the decreased availability of HSA to carry other essential compounds.