caa a22 4500 445328681 CHVBK 20180317142730.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10953-010-9640-8 doi (NATIONALLICENCE)springer-10.1007/s10953-010-9640-8 Binding Mechanism of Bioactive Cetirizine Hydrochloride to Sudlow's Site I of Serum Albumins [Elektronische Daten] [Ashwini Hegde, B. Sandhya, Shankara Kalanur, J. Seetharamappa] The mechanism of interaction of an anti-allergic drug, cetirizine dihydrochloride, with the proteins bovine and human serum albumins has been investigated by spectrofluorimetry, FTIR, UV-vis absorption and circular dichroism methods at physiological conditions. The drug was found to quench the fluorescence intensity of the protein through a dynamic quenching mechanism. Various binding parameters were evaluated based on fluorescence quenching studies carried out at 293K, 301K and 308K. The nature of the binding force operating between the drug and protein was proposed, based on the measured thermodynamic parameters. Achange in the secondary structure of the protein was evident from the circular dichroism measurements, wherein the α-helicity decreased from 65.69% to 51.23% and from 42.7% to 38.55% for the CTZ-BSA and CTZ-HSA systems, respectively. Based on Förster's theory of non-radiative energy transfer, the distance between the protein and drug was determined. The common blood plasma ions K+, Cu2+, Ni2+, Mn2+ and Co2+ were found to influence the binding of the drug to the protein. Displacement experiments were carried out to determine the binding site for drug on the protein. These studies, coupled with other spectroscopic results, revealed that the drug was bound to the hydrophobic pocket located in sub domain IIA of siteI. Springer Science+Business Media, LLC, 2011 Cetirizine hydrochloride nationallicence Serum albumins nationallicence Spectroscopic techniques nationallicence Hydrophobic interaction nationallicence Conformational studies nationallicence Hegde Ashwini Karnatak University, Dharwad, India aut Sandhya B. Karnatak University, Dharwad, India aut Kalanur Shankara Karnatak University, Dharwad, India aut Seetharamappa J. Karnatak University, Dharwad, India aut Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/2(2011-02-01), 182-197 0095-9782 40:2<182 2011 40 10953 https://doi.org/10.1007/s10953-010-9640-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10953-010-9640-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hegde Ashwini Karnatak University, Dharwad, India aut NATIONALLICENCE 700 1- Sandhya B. Karnatak University, Dharwad, India aut NATIONALLICENCE 700 1- Kalanur Shankara Karnatak University, Dharwad, India aut NATIONALLICENCE 700 1- Seetharamappa J. Karnatak University, Dharwad, India aut NATIONALLICENCE 773 0- Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/2(2011-02-01), 182-197 0095-9782 40:2<182 2011 40 10953 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer