Thermal Stabilization of Enzymes with Molecular Brushes

Abstract

Herein, we report a conjugation strategy, where we utilize a poly(ethylene oxide) cylindrical molecular brush architecture to design a self-assembled structure for thermal stabilization of enzymes. We demonstrate that the proposed architecture of the moderately stiff polymer ligand results in a significant improvement of biocatalytic activity and thermal stability of lysozyme and trypsin that retain their activity, even upon heating to 100 °C and above. The molecular brush is bound via epoxy functional groups to the amino groups of the lysine on the surface of the enzyme globule, promoting the formation of stiff and crowded cages around the enzymes and preventing the water molecules access to the enzyme and enzymes agglomeration. The molecular dynamic simulations show that the high concentration of poly(ethylene oxide) in the vicinity of the enzyme is critical for their stability. Monitoring of lysozyme–molecular brush conjugates for 6 and 12 months in lyophilized form and in solution, respectively, has s...