Characterization of the binding and conformational changes of bovine serum albumin upon interaction with antihypertensive olmesartan medoxomil

The interaction of bovine serum albumin (BSA) with the olmesartan medoxomil (OLM) was investigated by different spectroscopic and linear sweep voltammetric techniques under experimentally optimised physiological conditions. The alteration of functional properties of BSA when quenched by OLM was illustrated by the continuous decrease of the fluorescence intensity of BSA upon addition of OLM. The quenching constants (K-sv) obtained were 0.71 x 10(4), 1.3 x 10(4) and 2.1 x 10(4) Lmol(-1) at 288, 298 and 308 K respectively. The binding mechanism was dynamic type quenching. The value of K is of the order of 104, indicating that a long-lasting interaction exists between OLM and BSA. The positive values of Ale and AS suggested the hydrophobic interactions play the major roles in the binding reaction. The conformational change of BSA after binding with OLM was demonstrated by the synchronous, FTIR and 3-D fluorescence spectral results. The effects of some common metal ions and site probes on binding of BSA- OLM were also investigated. (C) 2018 Elsevier B.V. All rights reserved.