Water Molecular System Dynamics Associated with Amyloidogenic Nucleation as Revealed by Real Time Near Infrared Spectroscopy and Aquaphotomics

Abstract

The formation of amyloid fibrils proceeds via a nucleation-dependent mechanism in which nucleation phase is generally associated with a high free energy resulting in the rate-limiting step. On the basis of this kinetic feature, the nucleation is one of the most crucial phases controlling the pathogenesis of amyloidoses, but little is known about the details of how protein molecules and surrounding environment vary at this stage. Here, we applied near infrared (NIR) spectral monitoring of water structural changes in real time during the nucleation-dependent fibrillation of insulin. Whilst multivariate spectral analysis in the 2050–2350 nm spectral region indicated cross-β formation, characteristic transformations of water structure have been detected in the spectral region 1300–1600 nm corresponding to the first overtone of water OH stretching vibrations. Furthermore, specific water spectral patterns (aquagrams) related to different water molecular conformations have been found along the course of protein nucleation and aggregation. Right in the beginning, dissociation of hydrogen-bonded network in bulk water and coinstantaneous protein and ion hydration were observed, followed by water hydrogen-bonded networks development, presumably forcing the nucleation. These specific transformations of water spectral pattern could be used further as a biomarker for early non-invasive diagnosis of amyloidoses prior to explosive amplification and deposits of amyloid fibrils.

Polyethylene glycol promotes autoxidation of cytochrome c

“…The structural properties of the water molecules that hydrated Cyt c were investigated by subtracting the NIR spectrum of the buffer from that of Cyt c ( Figure 4B). The difference spectrum revealed a positive peak at 1412 nm and a negative peak at 1490 nm, which were assigned to vibrations from the weakly and strongly hydrogen-bonded water, respectively [35,36]. The peaks at 1412 and 1490 nm in the difference spectrum between 10 M Cyt c and the buffer were smaller than those in the difference spectrum between 50 M Cyt c and the buffer.…”

Monitoring of Water Spectral Pattern Reveals Differences in Probiotics Growth When Used for Rapid Bacteria Selection

“…Most of the bands with high variations of their absorbance were consistent with the described 12 water matrix coordinates (WAMACS) [ 16 ] described for the first overtone of water. Among these wavelengths is 1386, which is in the region 1370–1408 and 1700 corresponding to higher protonated water clusters [ 32 , 34 ]. The bands at 1484 and 1492 correspond to the first order stretching overtone of O–H-O and the first overtone of the highly hydrogen bonded S 4 , ((H 2 O) 4 ), water cluster, respectively.…”

Water Bridging Dynamics of Polymerase Chain Reaction in the Gauge Theory Paradigm of Quantum Fields

“…Such a dipole rotational symmetry is broken by the interaction with the dipole radiative fields of DNA and enzyme molecules. Our aim is to study the collective rotational transitions in the water dipole field induced by such radiative interactions [8,[31][32][33][34].…”