Hen egg white lysozyme fibrillation: a deep‐UV resonance Raman spectroscopic study

Abstract

Amyloid fibrils are associated with numerous degenerative diseases. The molecular mechanism of the structural transformation of native protein to the highly ordered cross-beta structure, the key feature of amyloid fibrils, is under active investigation. Conventional biophysical methods have limited application in addressing the problem because of the heterogeneous nature of the system. In this study, we demonstrated that deep-UV resonance Raman (DUVRR) spectroscopy in combination with circular dichroism (CD) and intrinsic tryptophan fluorescence allowed for quantitative characterization of protein structural evolution at all stages of hen egg white lysozyme fibrillation in vitro. DUVRR spectroscopy was found to be complimentary to the far-UV CD because it is (i) more sensitive to beta -sheet than to alpha -helix, and (ii) capable of characterizing quantitatively inhomogeneous and highly light-scattering samples. In addition, phenylalanine, a natural DUVRR spectroscopic biomarker of protein structural rearrangements, exhibited substantial changes in the Raman cross section of the 1000-cm(-1) band at various stages of fibrillation.

Conformational changes and bioactivity of lysozyme on binding to and desorption from magnetite nanoparticles

“…As calculated from Eqs. (2) and (3), the percentage of ␣-helix in native lysozyme is 31.2% which is near the literature value of 32% [32]. The ␣-helix percentage for lysozyme desorbed by PBS (20 mM, pH 5.0, 0.2 M NaCl) and PBS (20 mM, pH 5.0, 0.5 M NaCl) are 30.07% and 28.7%, close to the native lysozyme, which clearly indicating that PBS (20 mM, pH 5.0, 0.2 M NaCl) and PBS (20 mM, pH 5.0, 0.5 M NaCl) could not destroy the protein hydrogen bonding networks and induce the secondary structure changes in lysozyme.…”

Resolution of localized small molecule–Aβ interactions by deep-ultraviolet resonance Raman spectroscopy

“…UVRR has been employed previously to characterize the core structure in Aβ(1-40) fibrils [56], as well as the fibrillization of other amyloidogenic peptides and proteins [57][58][59][60][61]. The UVRR spectrum of LMW Aβ(1-42) is visually similar to other disordered homo-polypeptides (Fig.…”

Exploring the structure and formation mechanism of amyloid fibrils by Raman spectroscopy: a review

“…18, 51 Asher's group developed a semi-empirical approach that allows calculating the psi (Ψ) dihedral angle of the polypeptide backbone based on the position of the amide III 3 band. 60,61 They also found some dependence of the amide III 3 Raman shift on the other, phi (Φ), angle.…”