scholarly journals Protein Hydration in a Bioprotecting Mixture

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 995
Author(s):  
Silvia Corezzi ◽  
Brenda Bracco ◽  
Paola Sassi ◽  
Marco Paolantoni ◽  
Lucia Comez
Keyword(s):  
Ternary Mixture ◽  
Degrees Of Freedom ◽  
Binary Solution ◽  
Broad Band ◽  
Protein Hydration ◽  
Hydration Water ◽  
Preferential Hydration ◽  
External Agents ◽  
Concentration Threshold ◽  
Depolarized Light Scattering

We combined broad-band depolarized light scattering and infrared spectroscopies to study the properties of hydration water in a lysozyme-trehalose aqueous solution, where trehalose is present above the concentration threshold (30% in weight) relevant for biopreservation. The joint use of the two different techniques, which were sensitive to inter-and intra-molecular degrees of freedom, shed new light on the molecular mechanism underlying the interaction between the three species in the mixture. Thanks to the comparison with the binary solution cases, we were able to show that, under the investigated conditions, the protein, through preferential hydration, remains strongly hydrated even in the ternary mixture. This supported the water entrapment scenario, for which a certain amount of water between protein and sugar protects the biomolecule from damage caused by external agents.

scholarly journals Hydration-dependent dynamic crossover phenomenon in protein hydration water

2014 ◽  
Vol 90 (4) ◽  
Author(s):  
Zhe Wang ◽  
Emiliano Fratini ◽  
Mingda Li ◽  
Peisi Le ◽  
Eugene Mamontov ◽  
...  
Keyword(s):  
Protein Hydration ◽  
Hydration Water ◽  
Dynamic Crossover

Transient Response of MDOF Systems With Inerters to Nonstationary Stochastic Excitation

2017 ◽  
Vol 84 (10) ◽  
Author(s):  
Sami F. Masri ◽  
John P. Caffrey ◽  
Hui Li
Keyword(s):  
Degrees Of Freedom ◽  
Broad Band ◽  
Primary System ◽  
Mean Square ◽  
Stochastic Excitation ◽  
Mass Ratio ◽  
Tuning Parameters ◽  
Mdof Systems ◽  
Mean Square Response ◽  
Arbitrary Location

Explicit, closed-form, exact analytical expressions are derived for the covariance kernels of a multi degrees-of-freedom (MDOF) system with arbitrary amounts of viscous damping (not necessarily proportional-type), that is equipped with one or more auxiliary mass damper-inerters placed at arbitrary location(s) within the system. The “inerter” is a device that imparts additional inertia to the vibration damper, hence magnifying its effectiveness without a significant damper mass addition. The MDOF system is subjected to nonstationary stochastic excitation consisting of modulated white noise. Results of the analysis are used to determine the dependence of the time-varying mean-square response of the primary MDOF system on the key system parameters such as primary system damping, auxiliary damper mass ratio, location of the damper-inerter, inerter mass ratio, inerter node choices, tuning of the coupling between the damper-inerter and the primary system, and the excitation envelope function. Results of the analysis are used to determine the dependence of the peak transient mean-square response of the system on the damper/inerter tuning parameters, and the shape of the deterministic intensity function. It is shown that, under favorable dynamic environments, a properly designed auxiliary damper, encompassing an inerter with a sizable mass ratio, can significantly attenuate the response of the primary system to broad band excitations; however, the dimensionless “rise-time” of the nonstationary excitation substantially reduces the effectiveness of such a class of devices (even when optimally tuned) in attenuating the peak dynamic response of the primary system.

scholarly journals Kolmogorov Unstable Stellar Oscillations

1983 ◽  
Vol 66 ◽  
pp. 297-321
Author(s):  
J. Perdang
Keyword(s):  
Numerical Analysis ◽  
Internal Resonance ◽  
Degrees Of Freedom ◽  
High Surface ◽  
Broad Band ◽  
Resonance Effects ◽  
Stellar Oscillations ◽  
Noise Type ◽  
Non Linear ◽  
Equipartition Of Energy

AbstractWe survey the mathematics of non-linear Hamiltonian oscillations with emphasis being laid on the more recently discovered Kolmogorov instability. In the context of radial adiabatic oscillations of stars this formalism predicts a Kolmogorov instability even at low oscillation energies, provided that sufficiently high linear asymptotic modes have been excited.Numerical analysis confirms the occurrence of this instability. It is found to show up already among the lowest order modes, although high surface amplitudes are then required (ǀδrǀ/R ~ 0.5 for an unstable fundamental mode – first harmonic coupling). On the basis of numerical evidence we conjecture that in the Kolmogorov unstable regime the enhanced coupling due to internal resonance effects leads to an equipartition of energy over all interacting degrees of freedom. We also indicate that the power spectrum of such oscillations is expected to display two components: A very broad band of overlapping pseudo-linear frequency peaks spread out over the asymptotic range, and a strictly non-linear 1/f-noise type component close to the frequency origin.It is finally argued that the Kolmogorov instability is likely to occur among non-linearly coupled non-radial stellar modes at a surface amplitude much lower than in the radial case. This lends support to the view that this instability might be operative among the solar oscillations.

scholarly journals Distinct Protein Hydration Water Species Defined by Spatially Resolved Spectra of Intermolecular Vibrations

2017 ◽  
Vol 121 (31) ◽  
pp. 7431-7442 ◽  
Author(s):  
Viren Pattni ◽  
Tatiana Vasilevskaya ◽  
Walter Thiel ◽  
Matthias Heyden
Keyword(s):  
Protein Hydration ◽  
Hydration Water ◽  
Spatially Resolved ◽  
Water Species ◽  
Intermolecular Vibrations

Some thermodynamical aspects of protein hydration water

2015 ◽  
Vol 142 (21) ◽  
pp. 215103 ◽  
Author(s):  
Francesco Mallamace ◽  
Carmelo Corsaro ◽  
Domenico Mallamace ◽  
Sebastiano Vasi ◽  
Cirino Vasi ◽  
...  
Keyword(s):  
Protein Hydration ◽  
Hydration Water

scholarly journals Modelling of propeller shaft dynamics at pulse load

2008 ◽  
Vol 15 (4) ◽  
pp. 52-58 ◽  
Author(s):  
Andrzej Grządziela
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Model Identification ◽  
Experimental Results ◽  
Real Object ◽  
Pulse Load ◽  
Propeller Shaft ◽  
Matlab Simulink ◽  
External Agents ◽  
Time Histories

Modelling of propeller shaft dynamics at pulse load The article discusses a method of modelling of propeller shaft dynamics at the presence of virtually introduced underwater detonation effects. The propeller shaft model has four degrees of freedom, which provides opportunities for introducing shaft displacements and rotations similar to those observed in a real object. The equations of motion, taking into account the action of external agents, were implemented to the Matlab SIMULINK environment. The obtained time-histories and their spectra were compared with the experimental results of the tests performed on the marine testing ground. The performed model identification confirmed its sensitivity to changing parameters of motion and external actions.

scholarly journals Unbiased Atomistic Insight in the Mechanisms and Solvent Role for Globular Protein Dimer Dissociation

2018 ◽  
Author(s):  
Faidon Z. Brotzakis ◽  
Peter G. Bolhuis
Keyword(s):  
Transition State ◽  
Degrees Of Freedom ◽  
Process Analysis ◽  
Salt Bridge ◽  
Underlying Mechanism ◽  
Full Detail ◽  
Hydration Water ◽  
Native Contact ◽  
Reorientation Dynamics

Association and dissociation of proteins are fundamental processes in nature. While this process is simple to understand conceptually, the details of the underlying mechanism and role of the solvent are poorly understood. Here we investigate the mechanism and solvent role for the dissociation of the hydrophilic β-lactoglobulin dimer by employing transition path sampling. Analysis of the sampled path ensembles indicates that dissociation (and association) occurs via a variety of mechanisms: 1) a direct aligned dissociation 2) a hopping and rebinding transition followed by unbinding 3) a sliding transition before unbinding. Reaction coordinate and transition state analysis predicts that, besides native contact and vicinity salt-bridge interactions, solvent degrees of freedom play an important role in the dissociation process. Analysis of the structure and dynamics of the solvent molecules reveals that the dry native interface induces enhanced populations of both disordered hydration water and hydration water with higher tetrahedrality, mainly nearby hydrophobic residues. Bridging waters, hydrogen bonded to both proteins, support contacts, and exhibit a faster decay and reorientation dynamics in the transition state than in the native state interface, which renders the proteins more mobile and assists in rebinding. While not exhaustive, our sampling of rare un-biased reactive molecular dynamics trajectories shows in full detail how proteins can dissociate via complex pathways including (multiple) rebinding events. The atomistic insight obtained assists in further understanding and control of the dynamics of protein-protein interaction including the role of solvent.PACS numbers:

Protein Hydration Water

2003 ◽  
pp. 213-225 ◽  
Author(s):  
Douglas J. Tobias ◽  
William I.-Feng Kuo ◽  
Ali Razmara ◽  
Mounir Tarek
Keyword(s):  
Protein Hydration ◽  
Hydration Water
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