Browsing by Subject "Human serum albumin"

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Open Access
Comparative serum albumin interactions and antitumor effects of Au(III) and Ga(III) ions
(Urban und Fischer Verlag GmbH und Co. KG, 2015) Sarioglu O.F.; Ozdemir, A.; Karaboduk, K.; Tekinay, T.
In the present study, interactions of Au(III) and Ga(III) ions on human serum albumin (HSA) were studied comparatively via spectroscopic and thermal analysis methods: UV-vis absorbance spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and isothermal titration calorimetry (ITC). The potential antitumor effects of these ions were studied on MCF-7 cells via Alamar blue assay. It was found that both Au(III) and Ga(III) ions can interact with HSA, however; Au(III) ions interact with HSA more favorably and with a higher affinity. FT-IR second derivative analysis results demonstrated that, high concentrations of both metal ions led to a considerable decrease in the α-helix content of HSA; while Au(III) led to around 5% of decrease in the α-helix content at 200μM, it was around 1% for Ga(III) at the same concentration. Calorimetric analysis gave the binding kinetics of metal-HSA interactions; while the binding affinity (Ka) of Au(III)-HSA binding was around 3.87×105M-1, it was around 9.68×103M-1 for Ga(III)-HSA binding. Spectroscopy studies overall suggest that both metal ions have significant effects on the chemical structure of HSA, including the secondary structure alterations. Antitumor activity studies on MCF7 tumor cell line with both metal ions revealed that, Au(III) ions have a higher antiproliferative activity compared to Ga(III) ions. © 2014 Elsevier GmbH.
Open Access
Investigation of binding properties of dicationic styrylimidazo[1,2-a]pyridinium dyes to human serum albumin by spectroscopic techniques
(John Wiley and Sons Ltd, 2017) Özdemir, A.; Gökoğlu, E.; Yılmaz, Esra; Yalçın, E.; Gökoğlu, E.; Seferoğlu, Z.; Tekinay, T.
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.