To stabilize alpha-chymotrypsin against irreversible thermal inactivation at high temperatures, methods of covalent modification and multi-point immobilization in combination with the addition of salting-in compounds were used. The upper limit of the protein stability proved to be the same for a combination of the modification and salting-in media and for each of these methods separately. The limit of stabilization reached by means of covalent immobilization is higher than the limit of stabilization reached by two other methods. The greatest stabilization of immobilized alpha-chymotrypsin by the salting-in media (a 10000 fold increase in the native enzyme's stability level) takes place only in the case of the protein with the minimum number of bonds with the support. Stabilization of the enzyme by these methods is explained in terms of the suppression of the conformational inactivation processes.
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Int J Biol Macromol
September 2021
Department of Chemistry and Biochemistry, Texas Christian University, 2950 W. Bowie St., Sid Richardson Bldg. #438, Fort Worth, TX 76129, USA.. Electronic address:
Metastable protein-rich microdroplets are produced from liquid-liquid phase separation (LLPS) of protein aqueous solutions. These globules can be intermediates for the formation of other protein-rich phases. Lysozyme aqueous solutions undergo LLPS around 0 °C in the presence of NaCl near physiological conditions.
View Article and Find Full Text PDFJ Solution Chem
July 2019
CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
The order of the salting-in or salting-out inducing ability of ions on the aqueous solubility of macromolecules in aqueous solutions is known as the Hofmeister series. Taking into account that ionic liquids (ILs) are constituted by ions, they can exert similar effects on the solubility of other ILs in aqueous media. In order to expand the knowledge on the salting-in/-out ability of ILs, experimental studies on the solubility of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonylimide) in water in presence of other IL/salts were conducted at 298.
View Article and Find Full Text PDFChem Sci
June 2019
Key Laboratory for Ultrafine Materials of Ministry of Education , School of Materials Science and Engineering , East China University of Science and Technology, Shanghai 200237 , China . Email:
Metal-organic frameworks (MOFs) are attracting immense research interest despite the fact that their synthesis usually proceeds in organic media or under harsh conditions depending on specific cases. Herein, Hofmeister effect was firstly introduced for the construction of MOFs and thereafter a general salting-in species (SS) induced self-assembly strategy was proposed for the aqueous-phase and mild synthesis of stable MOFs based on a unique "solubilization-mediating" mechanism. The SS not only improved the solubility of organic ligands, but also effectively mediated the mutual proximity of the organic linkers and the inorganic nodes, thus facilitating the crystallization of MOFs under mild conditions.
View Article and Find Full Text PDFPolymers (Basel)
March 2018
University of Potsdam, Institute of Chemistry, Karl-Liebknecht-Str. 24⁻25, D-14476 Potsdam-Golm, Germany.
Nonionic-zwitterionic diblock copolymers are designed to feature a coil-to-globule collapse transition with an upper critical solution temperature (UCST) in aqueous media, including physiological saline solution. The block copolymers that combine presumably highly biocompatible blocks are synthesized by chain extension of a poly(ethylene glycol) (PEG) macroinitiator via atom transfer radical polymerization (ATRP) of sulfobetaine and sulfabetaine methacrylates. Their thermoresponsive behavior is studied by variable temperature turbidimetry and ¹H NMR spectroscopy.
View Article and Find Full Text PDFJ Phys Chem B
April 2016
Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, Technische Universität Dortmund, Emil-Figge-Strasse 70, 44227 Dortmund, Germany.
This study investigates the influence of electrolytes on the performance of extracting 5-hydroxymethylfurfural (HMF) from aqueous media using methyl isobutyl ketone (MIBK). For that purpose, liquid-liquid phase equilibria (LLE) of quaternary systems containing HMF, water, MIBK and salts were measured at atmospheric pressure and 298.15 K.
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