Investigation of binding properties of dicationic styrylimidazo[1,2-a]pyridinium dyes to human serum albumin by spectroscopic techniques.
The binding interaction between two dicationic styrylimidazo[1,2-a]pyridinium dyes and human serum albumin (HSA) was investigated at physiological conditions using fluorescence, UV-vis absorption, and circular dichroism (CD) spectroscopies. Analysis of the fluorescence titration data at different temperatures suggested that the fluorescence quenching mechanism of HSA by these dyes was static. The calculated thermodynamic parameters (ΔG°, ΔH° and ΔS°) indicated that hydrogen bonding and van der Waals forces played a major role in the formation of the dye-HSA complex. Binding distances (r) between dyes and HSA were calculated according to Förster's non-radiative energy transfer theory. Studies of conformational changes of HSA using CD measurements indicate that the α-helical content of the protein decreased upon binding of the dyes. Copyright © 2016 John Wiley & Sons, Ltd.
UNAM - National Nanotechnology Research Center, Bilkent University, Bilkent, 06800, Ankara, Turkey.
Ayşe
A
Özdemir
Department of Chemistry, Hacettepe University, Beytepe, 06800, Ankara, Turkey.
Elmas
E
Gökoğlu
Department of Chemistry, Hacettepe University, Beytepe, 06800, Ankara, Turkey.
EsraYılmaz
Department of Chemistry, Gazi University, Ankara, 06500, Turkey.
Ergin
E
Yalçın
Department of Chemistry, Hacettepe University, Beytepe, 06800, Ankara, Turkey.
Esra
E
Gökoğlu
Department of Chemistry, Gazi University, Ankara, 06500, Turkey.
Zeynel
Z
Seferoğlu
Department of Medical Biology and Genetics, Faculty of Medicine, Gazi University, 06500, Besevler, Ankara, Turkey.|Life Sciences Application and Research Center, Gazi University, 06830, Gölbaşi, Ankara, Turkey.
Turgay
T
Tekinay
D001665:Binding Sites; D002412:Cations / Q000737:chemistry; D002942:Circular Dichroism; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D007093:Imidazoles / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
D002412:Cations; D005456:Fluorescent Dyes; D007093:Imidazoles; D011726:Pyridinium Compounds; D012709:Serum Albumin; C000617301:styrylimidazo(1,2-a)pyridinium
binding mode; circular dichroism; dicationic styryl dyes; fluorescence quenching; human serum albumin