Merck
  • Home
  • Search Results
  • Macromolecular Crowding Modifies the Impact of Specific Hofmeister Ions on the Coil-Globule Transition of PNIPAM.

Macromolecular Crowding Modifies the Impact of Specific Hofmeister Ions on the Coil-Globule Transition of PNIPAM.

The journal of physical chemistry. B (2015-07-29)
Kenji Sakota, Daiki Tabata, Hiroshi Sekiya
ABSTRACT

Macromolecular crowding alters many biological processes ranging from protein folding and enzyme reactions in vivo to the precipitation and crystallization of proteins in vitro. Herein, we have investigated the effect of specific monovalent Hofmeister salts (NaH2PO4, NaF, NaCl, NaClO4, and NaSCN) on the coil-globule transition of poly(N-isopropylacrylamide) (PNIPAM) in a crowded macromolecular environment as a model for understanding the specific-ion effect on the solubility and stability of proteins in a crowded macromolecular environment. It was found that although the salts (NaH2PO4, NaF, and NaCl) and the macromolecular crowder (polyethylene glycol) lowered the transition temperature almost independently, the macromolecular crowder had a great impact on the transition temperature in the case of the chaotropes (NaClO4 and NaSCN). The electrostatic repulsion between the chaotropic anions (ClO4(-) or SCN(-)) adsorbed on PNIPAM may reduce the entropic gain of water associated with the excluded volume effect, leading to an increase in the transition temperature, especially in the crowded environment. Furthermore, the affinity of the chaotropic anions for PNIPAM becomes small in the crowded environment, leading to further modification of the transition temperature. Thus, we have revealed that macromolecular crowding alters the effect of specific Hofmeister ions on the coil-globule transition of PNIPAM.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Sodium fluoride, SAJ first grade, ≥97.0%
Sigma-Aldrich
L-Lysine monohydrochloride, SAJ special grade, ≥99.0%
Sigma-Aldrich
L-Lysine monohydrochloride, BioUltra, ≥99.5% (AT)
Sigma-Aldrich
Sodium fluoride, BioXtra, ≥99%
Sigma-Aldrich
L-Lysine monohydrochloride, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 98.5-101.0%
Sigma-Aldrich
Sodium fluoride, BioReagent, suitable for insect cell culture, ≥99%
Sigma-Aldrich
L-Lysine monohydrochloride, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
Sodium fluoride, 99.99% trace metals basis
Sigma-Aldrich
Sodium fluoride, JIS special grade, ≥99.0%
Sigma-Aldrich
Sodium fluoride, LR, ≥97%
Sigma-Aldrich
Sodium chloride solution, 0.85%
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride-35Cl, 99 atom % 35Cl
Sigma-Aldrich
Sodium chloride, random crystals, optical grade, 99.9% trace metals basis
Sigma-Aldrich
Sodium chloride, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Sodium chloride, tablet
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
Sodium fluoride solution
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
Sodium chloride solution, 5 M
Sigma-Aldrich
Sodium chloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99%
Sigma-Aldrich
Sodium chloride, meets analytical specification of Ph. Eur., BP, USP, 99.0-100.5%
Sigma-Aldrich
Sodium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Sigma-Aldrich
Sodium chloride solution, BioUltra, for molecular biology, ~5 M in H2O
Sigma-Aldrich
Sodium chloride solution, 1 M
Sigma-Aldrich
Sodium chloride solution, 0.1 M
Sigma-Aldrich
Sodium chloride, JIS special grade, ≥99.5%