TY - GEN A1 - Böhler, Stefan A1 - Rosencrantz, Sophia A1 - Wolf, Karina A1 - Heinemann, Robert A1 - Schmidt, Peer A1 - Ganster, Johannes A1 - Büsse, Thomas A1 - Balko, Jens A1 - Rosencrantz, Ruben R. T1 - Active protease formulation in commodity polymers withstands melt processing into compounds and blown films T2 - Materials Today Communications N2 - Integrating enzymes into thermoplastic polymers is challenging due to their lack of robustness with respect to temperature and shear fields during conventional melt processing. In the present study, blown films from low-density polyethylene (LDPE) were prepared containing a technical protease from Bacillus sp. First, LDPE/protease compounds were produced followed by blown film extrusion, both processes at melt mass temperatures of 130 °C or higher. Enzyme activity was proven, both for the LDPE/protease compound and the blown film. The highest enzyme activity in the compound was determined for processing at 132 °C and a screw speed of 75 rpm. The influence of melt temperature and shear fields was studied in detail. Enzyme activities were determined for melt temperatures up to 160 °C and for screw speeds ranging from 75 to 300 rpm during compounding by twin-screw extrusion. The process was also applied for biobased and biodegradable polyesters, where similar protease activity after compounding was verified. Electron microscopy, X-ray diffraction, nuclear magnetic resonance spectroscopy and differential scanning calorimetry served to analyze components and morphology of the enzyme formulation used here. It is proposed that the porous morphology of the protease particles is beneficial for the enzyme to remain active after processing. Additionally, the polymer matrix surrounding the particles protects the protease at elevated temperatures, which can be attributed to thermal insulation. Thus, the right combination of a suited technical enzyme formulation with appropriate mild melt compounding conditions allows enzymes to be incorporated into thermoplastics and retain their activity. This opens the way to use the abundant biological functions of enzymes in thermoplastic applications. KW - Thermal analysis KW - X-ray diffraction KW - Crystal structure Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2352492822018591 U6 - https://doi.org/10.1016/j.mtcomm.2022.105018 SN - 2352-4928 VL - 34 SP - 1 EP - 9 ER - TY - GEN A1 - Neubert, Tilmann J. A1 - Hielscher, Maximilian M. A1 - Walter, Keven A1 - Schröter, Carolin M. A1 - Stage, Marion A1 - Rosencrantz, Ruben R. A1 - Panis, Felix A1 - Rompel, Annette A1 - Balasubramanian, Kannan A1 - Waldvogel, Siegfried R. A1 - Börner, Hans G. T1 - Electrosynthesis of mussel‐inspired adhesive polymers as a novel class of transient enzyme stabilizers T2 - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker. International edition N2 - Multifunctional ortho‐quinones are required for the formation of thiol‐catechol‐connectivities (TCC) but can be delicate to handle. We present the electrochemical oxidation of the dipeptide DiDOPA, achieving up to 92 % conversion efficiency of the catechols to ortho‐quinones. Graphite and stainless steel could be employed as cost‐efficient electrodes. The electrochemical activation yields quinone‐solutions, which are free of undesired reactive compounds and eliminates the challenging step of isolating the reactive quinones. The DiDOPA quinones were employed in polyaddition reactions with multi‐thiols, forming oligomers that functioned as transient enzyme stabilizers (TES). These TCC‐TES‐additives improved the thermal stability and the activity of tyrosinase in heat stress assays. KW - Electrosynthesis KW - Protein engineering KW - PEGylation KW - Green chemistry KW - Peptide adhesive Y1 - 2025 U6 - https://doi.org/10.1002/anie.202419684 SN - 1433-7851 SN - 1521-3773 VL - 64 IS - 6 SP - 1 EP - 8 PB - Wiley-VCH CY - Weinheim ER -