Hydration and interactions in protein solutions containing concentrated electrolytes studied by small-angle scattering

Zhang, F.; Roosen-Runge, Felix; Skoda, Maximilian W. A.; Jacobs, Robert M.; Wolf, Melanie; Callow, Philip; Frielinghaus, Henrich; Pipich, Vitaliy; Prévost, Sylvain; Schreiber, Frank

doi:10.1039/c2cp23460b

Cited by 93 publications

(90 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As observed in a series of small-angle neutron scattering (SANS) measurements of bovine serum albumin (82,83), 1100 water molecules (corresponding to 0.3-0.4 g H 2 O/g albumin) are considered to ''bound'' around a protein molecule, forming a higher density water layer. Given that a complete hydration monolayer around albumin would contain 1070 water molecules (84), the SANS result represents a single hydration shell around albumin and the existence of further hydration layers was not checked for.…”

Section: Hydration Statementioning

confidence: 99%

“…Although earlier studies have implied NHB water is correlated with protein unfolding (5,83), the relationship between protein functionality and NHB water is still obscure due to experimental difficulties in probing NHB water. Further THz experiments are expected to provide deeper insight into the role of NHB water in the biological functionality of proteins, such as enzyme reactions.…”

Section: Fragmentation Of Water-water Hbsmentioning

confidence: 99%

See 1 more Smart Citation

Hydrogen Bond Network of Water around Protein Investigated with Terahertz and Infrared Spectroscopy

Shiraga

Ogawa

Kondo

2016

Biophysical Journal

View full text Add to dashboard Cite

The dynamical and structural properties of water at protein interfaces were characterized on the basis of the broadband complex dielectric constant (0.25 to 400 THz) of albumin aqueous solutions. Our analysis of the dielectric responses between 0.25 and 12 THz first revealed hydration water with retarded reorientational dynamics extending~8.5 Å (corresponding to three to four layers) out from the albumin surface. Second, the number of nonhydrogen-bonded water was decreased in the presence of the albumin solute, indicating protein inhibits the fragmentation of the water hydrogen-bond network. Finally, water molecules at the albumin interface were found to form a distorted hydrogen-bond structure due to topological and energetic disorder of the protein surface. In addition, the intramolecular O-H stretching vibration of water (~100 THz), which is sensitive to hydrogen-bond environment, pointed to a trend that hydration water has a larger population of strongly hydrogen-bonded water molecules compared with that of bulk water. From these experimental results, we concluded that the ''strengthened'' water hydrogen bonds at the protein interface dynamically slow down the reorientational motion of water and form the less-defective hydrogen-bond network by inhibiting the fragmentation of water-water hydrogen bonds. Nevertheless, such a strengthened water hydrogen-bond network is composed of heterogeneous hydrogen-bond distances and angles, and thus characterized as structurally ''distorted.''

show abstract

Section: Hydration Statementioning

confidence: 99%

Section: Fragmentation Of Water-water Hbsmentioning

confidence: 99%

Hydrogen Bond Network of Water around Protein Investigated with Terahertz and Infrared Spectroscopy

Shiraga

Ogawa

Kondo

2016

Biophysical Journal

View full text Add to dashboard Cite

show abstract

“…Small-angle scattering of x-rays (SAXS) and neutrons (SANS) are particularly suited to probe the structural properties of hydration layers around biomacromolecules in solution (28)(29)(30)(31)(32)(33). SAXS and SANS are sensitive to the electronic and nuclear scattering-length density (SLD) fluctuations, Dr, respectively, between solutes (i.e., biomacromolecules) and the bulk solvent (29).…”

Section: Introductionmentioning

confidence: 99%

SAXS/SANS on Supercharged Proteins Reveals Residue-Specific Modifications of the Hydration Shell

Kim

Martel

Girard

et al. 2016

Biophysical Journal

View full text Add to dashboard Cite

Water molecules in the immediate vicinity of biomacromolecules, including proteins, constitute a hydration layer characterized by physicochemical properties different from those of bulk water and play a vital role in the activity and stability of these structures, as well as in intermolecular interactions. Previous studies using solution scattering, crystallography, and molecular dynamics simulations have provided valuable information about the properties of these hydration shells, including modifications in density and ionic concentration. Small-angle scattering of x-rays (SAXS) and neutrons (SANS) are particularly useful and complementary techniques to study biomacromolecular hydration shells due to their sensitivity to electronic and nuclear scattering-length density fluctuations, respectively. Although several sophisticated SAXS/SANS programs have been developed recently, the impact of physicochemical surface properties on the hydration layer remains controversial, and systematic experimental data from individual biomacromolecular systems are scarce. Here, we address the impact of physicochemical surface properties on the hydration shell by a systematic SAXS/SANS study using three mutants of a single protein, green fluorescent protein (GFP), with highly variable net charge (þ36, À6, and À29). The combined analysis of our data shows that the hydration shell is locally denser in the vicinity of acidic surface residues, whereas basic and hydrophilic/hydrophobic residues only mildly modify its density. Moreover, the data demonstrate that the density modifications result from the combined effect of residue-specific recruitment of ions from the bulk in combination with water structural rearrangements in their vicinity. Finally, we find that the specific surface-charge distributions of the different GFP mutants modulate the conformational space of flexible parts of the protein.

show abstract

“…This effective diameter reflects the volume of the protein and the hydration layer visible to SAXS, but does not include thermo-and hydrodynamic effects of nonsphericity [34,35]. Thus, it should be considered as a lower boundary to the effective sphere diameter.…”

Section: Single-particle Propertiesmentioning

confidence: 99%

Viscosity and diffusion: crowding and salt effects in protein solutions

et al. 2012

View full text Add to dashboard Cite

We report on a joint experimental-theoretical study of collective diffusion in, and static shear viscosity of solutions of bovine serum albumin (BSA) proteins, focusing on the dependence on protein and salt concentration. Data obtained from dynamic light scattering and rheometric measurements are compared to theoretical calculations based on an analytically treatable spheroid model of BSA with isotropic screened Coulomb plus hard-sphere interactions. The only input to the dynamics calculations is the static structure factor obtained from a consistent theoretical fit to a concentration series of small-angle X-ray scattering (SAXS) data. This fit is based on an integral equation scheme that combines high accuracy with low computational cost. All experimentally probed dynamic and static properties are reproduced theoretically with an at least semi-quantitative accuracy. For lower protein concentration and low salinity, both theory and experiment show a maximum in the reduced viscosity, caused by the electrostatic repulsion of proteins. The validity range of a generalized Stokes-Einstein (GSE) relation connecting viscosity, collective diffusion coefficient, and osmotic compressibility, proposed by Kholodenko and Douglas [PRE, 1995[PRE, , 51, 1081 is examined. Significant violation of the GSE relation is found, both in experimental data and in theoretical models, in semi-dilute systems at physiological salinity, and under low-salt conditions for arbitrary protein concentrations.

show abstract

Hydration and interactions in protein solutions containing concentrated electrolytes studied by small-angle scattering

Cited by 93 publications

References 76 publications

Hydrogen Bond Network of Water around Protein Investigated with Terahertz and Infrared Spectroscopy

Hydrogen Bond Network of Water around Protein Investigated with Terahertz and Infrared Spectroscopy

SAXS/SANS on Supercharged Proteins Reveals Residue-Specific Modifications of the Hydration Shell

Viscosity and diffusion: crowding and salt effects in protein solutions

Contact Info

Product

Resources

About