Investigating hydrogen peroxide induced damage to alpha-2-macroglobulin: Biophysical and thermodynamic study

Publication date: 5 November 2019Source: Journal of Molecular Structure, Volume 1195Author(s): Tooba Siddiqui, Mohammad Khalid Zia, Syed Saqib Ali, Haseeb Ahsan, Fahim Halim KhanAbstractHydrogen peroxide (H2O2) is an important signalling molecule and a non-radical reactive oxygen species (ROS) which can convert into more potent oxygen radicals leading to oxidative stress. The correlation between oxidative stress and the cellular proteinase-antiproteinase balance has been a major component in the development of several pathologies such as emphysema and cystic fibrosis. The present studies attempt to explore the functional inactivation and structural alterations induced in one of the major antiproteinase, alpha-2-macroglobulin (α2M) on interaction with H2O2. α2M, purified from sheep blood plasma is a highly abundant proteinase inhibitor which acts as a backup or reserve force of antiproteinase. Our studies provide biophysical insights into the interaction of H2O2 with sheep α2M. Result demonstrates that antiproteolytic activity of α2M was significantly lowered upon interaction with increasing concentration of H2O2. Analysis of fluorescence spectra reveals quenching of fluorescence intensity in a static manner which occurs due to ground state complex formation. Synchronous fluorescence illustrates alteration in microenvironment around tryptophan and tyrosine residues of α2M. Additionally, UV/visible spectroscopy, circular dichroism and fourier transform infrared spectroscop...
Source: Journal of Molecular Structure - Category: Molecular Biology Source Type: research