albumin - publications
Differential Modulation in Binding of Ketoprofen to Bovine Serum Albumin in the Presence and Absence of Surfactants: Spectroscopic and Calorimetric Insights.
Chem Biol Drug Des. 2013 Mar 21;
Authors: Misra PP, Kishore N
Surfactants have long been implicated in the unique static and dynamic effect on the structure and function of serum albumins. However, there is very little information on the mode of interactions of drugs to serum albumins in presence of surfactants. The importance of such studies lay in the fact that apart from binding to serum albumins, surfactants are known to radically influence the solvents' micro environment and protein structure. Thus, we have studied the binding of the racemic form of ketoprofen (KPF) with bovine serum albumin (BSA) at pH 7.4 in the presence and absence of hexadecyl trimethyl ammonium bromide (HTAB), sodium dodecyl sulphate (SDS), Triton X-100 (TX-100) and NaCl. The structural studies of KPF with BSA as investigated by circular dichroism spectroscopy revealed a significant stabilization of BSA. However, the combined presence of the surfactants, NaCl and KPF demonstrated an extremely erratic behavior in terms of stabilization. Futher the values of Stern-Volmer and dynamic quenching constant suggested the binding site of KPF to be scattered in the region of domain I B and II A, close to Trp 134. The results of differential scanning calorimetry (DSC) revealed that the binding of KPF to BSA leads to its temperature dependent separation into two units. The binding parameters of BSA obtained from isothermal titration calorimetry in the combined presence of KPF and surfactants/NaCl correlate well with the DSC studies further confirming the localization of KPF in domain I B and II A. In the combined presence of surfactants, NaCl and KPF, the binding of KPF to BSA exhibited altered binding parameters far different from the binding of KPF alone. Overall the experimental findings strongly indicated positive as well as negative modulation in the binding of KPF to BSA in the presence of ligands. © 2013 John Wiley & Sons A/S.
PMID: 23517326 [PubMed - as supplied by publisher]