Infrared study of the state of water in the hydration shell of DNA

1970 ◽  
Vol 48 (10) ◽  
pp. 1536-1542 ◽  
Author(s):  
Michael Falk ◽  
A. G. Poole ◽  
C. G. Goymour
Keyword(s):  
Liquid Water ◽  
Low Temperatures ◽  
Hydration Shell ◽  
The State ◽  
Water Molecules ◽  
Surrounding Water ◽  
Infrared Study ◽  
Hydration Shells ◽  
State Of Water ◽  
Bond Strengths

The state of water in the hydration shell of DNA was studied by infrared spectroscopy. The stretching bands of isotopically dilute HDO adsorbed on DNA have nearly the same band profiles as those of HDO in liquid water. This indicates a distribution of hydrogen-bond strengths similar to that in liquid water. At low temperatures, the spectra show that an inner layer of about 10 water molecules per nucleotide is incapable of crystallization, even when the surrounding water crystallizes into ice I. The biopolymer hydration shells are not "ice-like" in the sense of crystalline ordering into an ice-like structure.

scholarly journals Hyaluronan orders water molecules in its nanoscale extended hydration shells

2021 ◽  
Vol 7 (10) ◽  
pp. eabf2558
Author(s):  
J. Dedic ◽  
H. I. Okur ◽  
S. Roke
Keyword(s):  
Second Harmonic ◽  
Hydration Shell ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Flexible Chain ◽  
Optical Modeling ◽  
Hydration Shells ◽  
Second Harmonic Scattering ◽  
Nuclear Quantum Effects ◽  
Extracellular Environment

Hyaluronan (HA) is an anionic, highly hydrated bio-polyelectrolyte found in the extracellular environment, like the synovial fluid between joints. We explore the extended hydration shell structure of HA in water using femtosecond elastic second-harmonic scattering (fs-ESHS). HA enhances orientational water-water correlations. Angle-resolved fs-ESHS measurements and nonlinear optical modeling show that HA behaves like a flexible chain surrounded by extended shells of orientationally correlated water. We describe several ways to determine the concentration-dependent size and shape of a polyelectrolyte in water, using the amount of water oriented by the polyelectrolyte charges as a contrast agent. The spatial extent of the hydration shell is determined via temperature-dependent measurements and can reach up to 475 nm, corresponding to a length of 1600 water molecules. A strong isotope effect, stemming from nuclear quantum effects, is observed when light water (H2O) is replaced by heavy water (D2O), amounting to a factor of 4.3 in the scattered SH intensity.

scholarly journals Origin and control of ionic hydration patterns in nanopores

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Miraslau L. Barabash ◽  
William A. T. Gibby ◽  
Carlo Guardiani ◽  
Alex Smolyanitsky ◽  
Dmitry G. Luchinsky ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Distribution Functions ◽  
Water Molecules ◽  
Surrounding Water ◽  
Ionic Hydration ◽  
Hydration Shells ◽  
Water Layers ◽  
Dynamics Simulations ◽  
And Control

AbstractIn order to permeate a nanopore, an ion must overcome a dehydration energy barrier caused by the redistribution of surrounding water molecules. The redistribution is inhomogeneous, anisotropic and strongly position-dependent, resulting in complex patterns that are routinely observed in molecular dynamics simulations. Here, we study the physical origin of these patterns and of how they can be predicted and controlled. We introduce an analytic model able to predict the patterns in a graphene nanopore in terms of experimentally accessible radial distribution functions, giving results that agree well with molecular dynamics simulations. The patterns are attributable to a complex interplay of ionic hydration shells with water layers adjacent to the graphene membrane and with the hydration cloud of the nanopore rim atoms, and we discuss ways of controlling them. Our findings pave the way to designing required transport properties into nanoionic devices by optimising the structure of the hydration patterns.

scholarly journals Water Properties of Soft Contact Lenses: A Comparative Near-Infrared Study of Two Hydrogel Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jelena Munćan ◽  
Ivana Mileusnić ◽  
Jovana Šakota Rosić ◽  
Aleksandra Vasić-Milovanović ◽  
Lidija Matija
Keyword(s):  
Water Content ◽  
Near Infrared ◽  
Contact Lenses ◽  
Polymer Network ◽  
The State ◽  
Vinyl Pyrrolidone ◽  
Soft Contact ◽  
Infrared Study ◽  
Soft Contact Lenses ◽  
State Of Water

The functionality of soft contact lenses depends strongly on the water content and their water-transport ability. This study was conducted in order to examine the state of water in two sets of soft contact lenses: VSO38, pHEMA Filcon I 1, and VSO50, copolymer of HEMA and VP Filcon II 1 (HEMA = 2-hydroxy-ethyl methacrylate; VP = vinyl pyrrolidone). Hydrogel lenses were studied using near-infrared spectroscopy and the novel Aquaphotomics approach in order to determine the state of water in materials based on their near-infrared spectra. Aquaphotomics approach investigates absorption at specific vibrational bands of water’s covalent and hydrogen bonds which can provide information on how the water structure changes with the structural change of the polymer network. Principal component analysis and specific star-chart “aquagram” were used to analyse water spectral pattern in hydrogel materials. The findings show that material VSO38 has water predominantly organized in bound state, while material with higher water content, VSO50, has more free and weakly hydrogen bonded water. Our findings define in detail exact water species existing and interacting with the polymer network. The results show qualitative and quantitative possibilities of Aquaphotomics for better modelling and understanding water behaviour in hydrogel materials.

scholarly journals Ice is born in low-mobility regions of supercooled liquid water

2019 ◽  
Vol 116 (6) ◽  
pp. 2009-2014 ◽  
Author(s):  
Martin Fitzner ◽  
Gabriele C. Sosso ◽  
Stephen J. Cox ◽  
Angelos Michaelides
Keyword(s):  
Liquid Water ◽  
Dynamical Behavior ◽  
Supercooled Liquid ◽  
Ice Nucleation ◽  
Water Molecules ◽  
Ice Crystal ◽  
Surrounding Water ◽  
Dynamical Heterogeneity ◽  
Complex Dynamical Behavior

When an ice crystal is born from liquid water, two key changes occur: (i) The molecules order and (ii) the mobility of the molecules drops as they adopt their lattice positions. Most research on ice nucleation (and crystallization in general) has focused on understanding the former with less attention paid to the latter. However, supercooled water exhibits fascinating and complex dynamical behavior, most notably dynamical heterogeneity (DH), a phenomenon where spatially separated domains of relatively mobile and immobile particles coexist. Strikingly, the microscopic connection between the DH of water and the nucleation of ice has yet to be unraveled directly at the molecular level. Here we tackle this issue via computer simulations which reveal that (i) ice nucleation occurs in low-mobility regions of the liquid, (ii) there is a dynamical incubation period in which the mobility of the molecules drops before any ice-like ordering, and (iii) ice-like clusters cause arrested dynamics in surrounding water molecules. With this we establish a clear connection between dynamics and nucleation. We anticipate that our findings will pave the way for the examination of the role of dynamical heterogeneities in heterogeneous and solution-based nucleation.

scholarly journals Origin and control of ionic hydration patterns in nanopores

2020 ◽  
Author(s):  
Miraslau Barabash ◽  
William Gibby ◽  
Carlo Guardiani ◽  
Alex Smolyanitsky ◽  
Dmitry Luchinsky ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Water Molecules ◽  
Complex Interplay ◽  
Surrounding Water ◽  
Ionic Hydration ◽  
Hydration Shells ◽  
Water Layers ◽  
Dynamics Simulations ◽  
And Control

Abstract In order to permeate a nanopore, an ion must overcome a dehydration energy barrier caused by the redistribution of surrounding water molecules. The redistribution is inhomogeneous, anisotropic and strongly position-dependent, resulting in complex patterns that are routinely observed in molecular dynamics simulations. We now address the questions of the physical origin of these patterns and of how they can be predicted and controlled. We introduce an analytic model able to predict the patterns in terms of experimentally accessible radial distributions functions, yielding results that agree well with molecular dynamics simulations. We show that the patterns are attributable to a complex interplay of ionic hydration shells with water layers adjacent to the membrane and with the hydration cloud of the nanopore rim atoms, and we discuss ways of controlling them. Our findings pave the way to designing required transport properties into nanoionic devices by optimising the structure of the hydration patterns.

Origin of ion selectivity at the air/water interface

2015 ◽  
Vol 17 (6) ◽  
pp. 4311-4318 ◽  
Author(s):  
Lu Sun ◽  
Xin Li ◽  
Yaoquan Tu ◽  
Hans Ågren
Keyword(s):  
Hydrogen Bonds ◽  
Weak Interactions ◽  
Ion Selectivity ◽  
Hydration Shell ◽  
Water Molecules ◽  
Water Interface ◽  
Hydration Shells ◽  
Air Water Interface ◽  
Water Hydrogen ◽  
First Hydration Shell

A snapshot of a water droplet consisting of Cs+ and I− ions with their hydration structures displayed. I− is hydrated anisotropically and the water–water hydrogen bonds in the first hydration shell are hindered. The anions have quite weak interactions with non-hydrogen-bonded water molecules in the first hydration shell, making it easier for them to leave the site. In contrast, cations obtain more stable hydration shells with an increase in their size.

Fourier Transform Infrared Study on the State of Water Sorbed to Poly(ethylene glycol) Films†

Langmuir ◽  
2001 ◽  
Vol 17 (6) ◽  
pp. 1889-1895 ◽  
Author(s):  
Hiromi Kitano ◽  
Ken Ichikawa ◽  
Makoto Ide ◽  
Mitsuhiro Fukuda ◽  
Wataru Mizuno
Keyword(s):  
Fourier Transform ◽  
Ethylene Glycol ◽  
Fourier Transform Infrared ◽  
The State ◽  
Poly Ethylene Glycol ◽  
Infrared Study ◽  
State Of Water ◽  
Poly Ethylene
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