The front cover artwork is provided by the Thiele group at Leibniz IPF Dresden (Germany). The image shows a microgel hosting cell‐free synthesis of green fluorescent protein. Despite its open, membrane‐free nature, the multifunctional microgel is also able to trap proteins inside its polymer matrix. Read the full text of the Article at 10.1002/syst.201900058.

We describe a bottom-up approach towards functional enzymes utilizing microgels as carriers for genetic information that enable cell-free protein synthesis, in situ immobilization, and utilization of functional deGFP-MatB.

Single-stranded deoxyribonucleic acids have an enormous potential for catalysis by applying tailored sequences of nucleotides for individual reaction conditions and substrates. If such a sequence is guanine-rich, it may arrange into a three-dimensional structure called G-quadruplex and give rise to a catalytically active DNA molecule, a DNAzyme, upon addition of hemin. Here, we present a DNAzyme-mediated reaction, which is the oxidation of l-tyrosine toward dityrosine by hydrogen peroxide. With an optimal stoichiometry between DNA and hemin of 1:10, we report an activity of 101.2 ± 3.5 μUnits (μU) of the artificial DNAzyme Dz-00 compared to 33.0 ± 1.8 μU of free hemin. Exemplarily, DNAzymes may take part in neurodegeneration caused by amyloid beta (Aβ) aggregation due to l-tyrosine oxidation. We show that the natural, human genome-derived DNAzyme In1-sp is able to oxidize Aβ peptides with a 4.6% higher yield and a 33.3% higher velocity of the reaction compared to free hemin. As the artificial DNAzyme Dz-00 is even able to catalyze Aβ peptide oxidation with a 64.2% higher yield and 337.1% higher velocity, an in-depth screening of human genome-derived DNAzymes may identify further candidates with similarly high catalytic activity in Aβ peptide oxidation.

The front cover artwork is provided by the Thiele group at Leibniz IPF Dresden (Germany). The image shows a microgel hosting cell-free synthesis of green fluorescent protein. Despite its open, membrane-free nature, the multifunctional microgel is also able to trap proteins inside its polymer matrix. Read the full text of the Article at 10.1002/syst.201900058. ChemSystemsChemCover Profile