scholarly journals Covalently Immobilized Lipase on a Thermoresponsive Polymer with an Upper Critical Solution Temperature as an Efficient and Recyclable Asymmetric Catalyst in Aqueous Media

ChemCatChem ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 1166-1172 ◽  
Author(s):  
Lan-Lan Lou ◽  
Huaxin Qu ◽  
Wenjun Yu ◽  
Bei Wang ◽  
Lezi Ouyang ◽  
...  
Keyword(s):  
Immobilized Lipase ◽  
Aqueous Media ◽  
Solution Temperature ◽  
Thermoresponsive Polymer ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Asymmetric Catalyst

scholarly journals Thermocontrolled Reversible Enzyme Complexation-Inactivation-Protection by Poly(N-acryloyl glycinamide)

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3601
Author(s):  
Pavel I. Semenyuk ◽  
Lidia P. Kurochkina ◽  
Lauri Mäkinen ◽  
Vladimir I. Muronetz ◽  
Sami Hietala
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Proteinase K ◽  
Solution Temperature ◽  
Proteolytic Degradation ◽  
Biotechnological Applications ◽  
Thermoresponsive Polymer ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature

A prospective technology for reversible enzyme complexation accompanied with its inactivation and protection followed by reactivation after a fast thermocontrolled release has been demonstrated. A thermoresponsive polymer with upper critical solution temperature, poly(N-acryloyl glycinamide) (PNAGA), which is soluble in water at elevated temperatures but phase separates at low temperatures, has been shown to bind lysozyme, chosen as a model enzyme, at a low temperature (10 °C and lower) but not at room temperature (around 25 °C). The cooling of the mixture of PNAGA and lysozyme solutions from room temperature resulted in the capturing of the protein and the formation of stable complexes; heating it back up was accompanied by dissolving the complexes and the release of the bound lysozyme. Captured by the polymer, lysozyme was inactive, but a temperature-mediated release from the complexes was accompanied by its reactivation. Complexation also partially protected lysozyme from proteolytic degradation by proteinase K, which is useful for biotechnological applications. The obtained results are relevant for important medicinal tasks associated with drug delivery such as the delivery and controlled release of enzyme-based drugs.

Selective Hydrogen Bonding Controls Temperature Response of Layer-by-Layer Upper Critical Solution Temperature Micellar Assemblies

Soft Matter ◽  
2021 ◽  
Author(s):  
Aliaksei Aliakseyeu ◽  
Victoria Albright ◽  
Danielle Yarbrough ◽  
Samantha Hernandez ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Methacrylic Acid ◽  
Temperature Response ◽  
Solution Temperature ◽  
Layer By Layer ◽  
Critical Solution Temperature ◽  
Hydrogen Bonding Interactions ◽  
Upper Critical Solution Temperature ◽  
Lbl Films

This work establishes a correlation between the selectivity of hydrogen-bonding interactions and the functionality of micelle-containing layer-by-layer (LbL) assemblies. Specifically, we explore LbL films formed by assembly of poly(methacrylic acid)...

Properties relating to critical phenomena in the acetic anhydride – acetone – carbon disulfide system

1970 ◽  
Vol 48 (6) ◽  
pp. 904-909 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark
Keyword(s):  
Acetic Anhydride ◽  
Carbon Disulfide ◽  
General Rule ◽  
Dielectric Constants ◽  
Excess Volumes ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Heats Of Mixing ◽  
Upper Critical Solution Temperature ◽  
Molar Polarization

The following physical properties of the acetic anhydride – acetone – carbon disulfide system have been investigated: congruent compositions, excess volumes, dielectric constants. For the system acetone – carbon disulfide, the excess volumes and the molar polarizations are much greater than those required by the mixture rule. From this we deduced that this system is very non-ideal and might, at a suitable temperature, form two layers; two liquid layers did indeed form at −73 °C, the upper critical solution temperature occurring somewhere between this temperature and 0 °C. We offer it as a general rule that, if the deviation from additivity of molar polarization is large and positive, two layers will form at a sufficiently low temperature, provided that solid phases do not intervene. This deduction becomes almost a certainty if large positive deviations from additivity of molar volume and large positive heats of mixing are also present.

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