Weakly Bound Water Molecules Shorten Single-Stranded DNA

2006 ◽  
Vol 128 (20) ◽  
pp. 6636-6639 ◽  
Author(s):  
Shuxun Cui ◽  
Christian Albrecht ◽  
Ferdinand Kühner ◽  
Hermann E. Gaub
Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1864
Author(s):  
Nikita Penkov

Terahertz spectroscopy allows for the analysis of vibrations corresponding to the large-scale structural movements and collective dynamics of hydrogen-bonded water molecules. Previously, differences had been detected in the emission spectra of interferon-gamma (IFNγ) solutions surrounded by extremely diluted solutions of either IFNγ or antibodies to IFNγ without direct contact compared to a control. Here we aimed to analyse the structural properties of water in a sample of an aqueous solution of IFNγ via terahertz time-domain spectroscopy (THz-TDS). Tubes with the IFNγ solution were immersed in fluidised lactose saturated with test samples (dilutions of antibodies to IFNγ or control) and incubated at 37 °C for 1, 1.5–2, 2.5–3, or 3.5–4 h. Fluidised lactose was chosen since it is an excipient in the manufacture of drugs based on diluted antibodies to IFNγ. After incubation, spectra were recorded within a wavenumber range of 10 to 110 cm−1 with a resolution of 4 cm−1. Lactose saturated with dilutions of antibodies to IFNγ (incubated for more than 2.5 h) changed the structural properties of an IFNγ aqueous solution without direct contact compared to the control. Terahertz spectra revealed stronger intermolecular hydrogen bonds and an increase in the relaxation time of free and weakly bound water molecules. The methodology developed on the basis of THz-TDS could potentially be applied to quality control of pharmaceuticals based on extremely diluted antibodies.


Soft Matter ◽  
2021 ◽  
Author(s):  
Helen Yao ◽  
Bradley D. Olsen

Small-angle neutron scattering is used to measure the number of bound water molecules associating with three polymers over a wide concentration range. Different fitting workflows are evaluated and recommended depending on the concentration regime.


Nature ◽  
1989 ◽  
Vol 340 (6232) ◽  
pp. 404-407 ◽  
Author(s):  
F. A. Quiocho ◽  
D. K. Wilson ◽  
N. K. Vyas

2014 ◽  
Vol 43 (17) ◽  
pp. 6315-6321 ◽  
Author(s):  
Lars Eklund ◽  
Ingmar Persson

The selenite ion has an asymmetric hydration sphere with loosely electrostatically bound water molecules outside the free electron pair.


1991 ◽  
Vol 46 (10) ◽  
pp. 1279-1286 ◽  
Author(s):  
Thomas Kellersohn ◽  
Konrad Beckenkamp ◽  
Heinz Dieter Lutz

The crystal structures of isotypic Sr(OH)Cl ·4 H2O, Sr(OH)Br·4 H2O, and Ba(OH)I·4 H2O are reported. The title compounds crystallize in a hitherto unknown structure type, space group PĪ, Z = 2. The final R values obtained are 0.0261, 0.069, and 0.062, respectively. The coordination of the metal ions is monocapped square antiprismatic with 7 H2O, 1 OH- and 1 halide ion. The halide ions separate metal/water/hydroxide layers. Each of the four crystallographically different water molecules serves as donor for one very strong and one very weak hydrogen bond and, hence, is extremely asymmetrically bound. Owing to this strong distortion, the largest one known so far, the OH stretching vibrations of the H2O molecules are intramolecularly decoupled as shown from vibrational spectra. The enthalpies of dehydration obtained from differential scanning calorimetry are reported.


2019 ◽  
Vol 75 (8) ◽  
pp. 1284-1290
Author(s):  
Sheridan Lynch ◽  
Genevieve Lynch ◽  
Will E. Lynch ◽  
Clifford W. Padgett

Four manganese(II) bromide coordination complexes have been prepared with four pyridine N-oxides, viz. pyridine N-oxide (PNO), 2-methylpyridine N-oxide (2MePNO), 3-methylpyridine N-oxide (3MePNO), and 4-methylpyridine N-oxide (4MePNO). The compounds are bis(μ-pyridine N-oxide)bis[aquadibromido(pyridine N-oxide)manganese(II)], [Mn2Br4(C5H5NO)4(H2O)2] (I), bis(μ-2-methylpyridine N-oxide)bis[diaquadibromidomanganese(II)]–2-methylpyridine N-oxide (1/2), [Mn2Br4(C6H7NO)2(H2O)4]·2C6H7NO (II), bis(μ-3-methylpyridine N-oxide)bis[aquadibromido(3-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(H2O)2] (III), and bis(μ-4-methylpyridine N-oxide)bis[dibromidomethanol(4-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(CH3OH)2] (IV). All the compounds have one unique MnII atom and form a dimeric complex that contains two MnII atoms related by a crystallographic inversion center. Pseudo-octahedral six-coordinate manganese(II) centers are found in all four compounds. All four compounds form dimers of Mn atoms bridged by the oxygen atom of the PNO ligand. Compounds I, II and III exhibit a bound water of solvation, whereas compound IV contains a bound methanol molecule of solvation. Compounds I, III and IV exhibit the same arrangement of molecules around each manganese atom, ligated by two bromide ions, oxygen atoms of two PNO ligands and one solvent molecule, whereas in compound II each manganese atom is ligated by two bromide ions, one O atom of a PNO ligand and two water molecules with a second PNO molecule interacting with the complex via hydrogen bonding through the bound water molecules. All of the compounds form extended hydrogen-bonding networks, and compounds I, II, and IV exhibit offset π-stacking between PNO ligands of neighboring dimers.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1107
Author(s):  
Wakana A. Azuma ◽  
Satoru Nakashima ◽  
Eri Yamakita ◽  
Tamihisa Ohta

Leaf water storage is a complex interaction between live tissue properties (anatomy and physiology) and physicochemical properties of biomolecules and water. How leaves adsorb water molecules based on interactions between biomolecules and water, including hydrogen bonding, challenges our understanding of hydraulic acclimation in tall trees where leaves are exposed to more water stress. Here, we used infrared (IR) microspectroscopy with changing relative humidity (RH) on leaves of tall Cryptomeria japonica trees. OH band areas correlating with water content were larger for treetop (52 m) than for lower-crown (19 m) leaves, regardless of relative humidity (RH). This high water adsorption in treetop leaves was not explained by polysaccharides such as Ca-bridged pectin, but could be attributed to the greater cross-sectional area of the transfusion tissue. In both treetop and lower-crown leaves, the band areas of long (free water: around 3550 cm−1) and short (bound water: around 3200 cm−1) hydrogen bonding OH components showed similar increases with increasing RH, while the band area of free water was larger at the treetop leaves regardless of RH. Free water molecules with longer H bonds were considered to be adsorbed loosely to hydrophobic CH surfaces of polysaccharides in the leaf-cross sections.


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