Amyloid-like protein formation and aortic valve calcification promoted by oxidative stress

I. Mamarelis, E. Koutoulakis, Ch. Kotoulas, V. Dritsa, V. Mamareli, K. Pissaridi, M. Kyriakidou, J. Anastassopoulou

Abstract

The mechanism of amyloid-like protein formation on aortic valve calcification and stenosis during oxidative stress was evaluated by using Attenuated total reflection Fourier transform infrared spectroscopy scanning electron microscopy and X-Ray diffraction. The high intensity bands of infrared spectra arising from the vibration modes of vCH3 and vCH2 of membranes’ lipids are related with increasing of lipophilic environment due to amyloid-like protein formation. The shifts to lower frequencies of Amide I/Amide II absorptions are associated with the transformation of α-helix to β-parallel and β-antiparallel sheets confirming the amyloid development. The formation of hydroxyapatite and CaHPO4 was supported by XRD analysis. The data showed that oxidative stress is a pathway of amyloid-like protein formation and the disulfide (S-S) bonds are the sites of calcium deposition.

Keywords: aortic valve stenosis, aortic valve calcification, amyloid proteins, fourier transform infrared spectroscopy, scanning electron microscopy, X-Ray diffraction