A Comparison Study of the Interaction of Progesterone and Testosterone Drugs with Human Serum Albumin: A Fluorescence Quenching Study

Abstract

The interaction of steroid hormones (testosterone and progesterone) with human serum albumin in phosphate buffer at pH 7.5 and at 25 °C have been studied using a fluorescence spectrophotometer. The results showed that fluorescence emission spectra were quenched with the increase of steroid molar ratios in fixed amount of HSA. The result indicated that progesterone and testosterone hormones have an ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. Two mathematical models Stern–Volmer and Scatchard for analysis of fluorescence spectra were used. Progesterone binding to HSA was increased by a factor of 2.6 greater than that detected for the interaction of testosterone with HSA. The values of Stern-Volmer constants were determined to be (2.0  104 L mol-1) for progesterone–HSA complex and (7.7  103 L mol-1) for testosterone–HSA complex, Respectively. Whereas, the Scatchard constants were (2.1  104 L mol-1) and (7.9  103 L mol-1) for progesterone–HSA and testosterone–HSA complexes, respectively

Keywords

• Steroid hormones, Human serum albumin, Stern-Volmer, Scatchard, Fluorescence quenching spectroscopy