Z Ghallasi Fakhrabady - Department of Biochemistry and Biophysics, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran
A neamati - Department of Biochemistry and Biophysics, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran
J Chamani - Department of Biochemistry and Biophysics, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran

The interaction between ACE peptide with human serum albumin (HSA) in λex= 280 nm and λex= 295 nm was studied with fluorescence spectroscopy. For the protein–peptide association reaction, quenching fluorescence measurements can give important informations about formation to the binding of peptide to protein. Also result of fluorescence spectroscopy showed that peptide could quench the HSA fluorescence spectra, and this quenching effect became more significant when the fluorescence spectra of HSA at different concentrations of peptide is related to λex = 280 nm than λex= 295 nm. It was obvious that HSA had a strong fluorescence emission at 343 nm after being excited with a wavelength of 280 nm and 295 nm. The addition of varying concentrations of peptide caused a noticeable decrease in the fluorescence intensity of HSA. The maximum emission wavelength produced a blue shift. The strong quenching of the Trp214 fluorescence indicated that the HSA conformation may have become changed and that an intermolecular energy transfer occurred between peptide and HSA. It was moreover an indication of the chromophore of protein being transferred to a more hydrophobic environment and the conformation of the protein becoming altered. The quenching of HSA fluorescence may be considered as a result of the formation of HAS - peptide complex and so transported peptid by this proten and act in body as a control hypertension therfor using as a supplement for spetial food product.

Human serum albumin, ACE peptide, Quenching, Fluorescence spectroscopy, Quenching Fluorescence