Selective Modification of the Product Profile of Biocatalytic Hydrolyzed PET via Product-Specific Medium Engineering.

Over the past years, enzymatic depolymerization of PET, one of the most widely used plastics worldwide, has become very efficient leading to the end products terephthalic acid (TPA) and ethylene glycol (EG) used for PET re-synthesis. Potent alternatives to these monomers are the intermediates BHET and MHET, the mono- and di-esters of TPA and EG which avoid total hydrolysis and can serve as single starting materials for direct re-polymerization. This study therefore aimed to selectively prepare those intermediates through reaction medium engineering during the biocatalytic hydrolysis of PET.

Co-Immobilization of a Multi-Enzyme Cascade: (S)-Selective Amine Transaminases, l-Amino Acid Oxidase and Catalase.

An enzyme cascade was established previously consisting of a recycling system with an l-amino acid oxidase (hcLAAO4) and a catalase (hCAT) for different α-keto acid co-substrates of (S)-selective amine transaminases (ATAs) in kinetic resolutions of racemic amines. Only 1 mol % of the co-substrate was required and l-amino acids instead of α-keto acids could be applied. However, soluble enzymes cannot be reused easily.

Recombinant l-Amino Acid Oxidase with Broad Substrate Spectrum for Co-substrate Recycling in (S)-Selective Transaminase-Catalyzed Kinetic Resolutions.

Chiral and enantiopure amines can be produced by enantioselective transaminases via kinetic resolution of amine racemates. This transamination reaction requires stoichiometric amounts of co-substrate. A dual-enzyme recycling system overcomes this limitation: l-amino acid oxidases (LAAO) recycle the accumulating co-product of (S)-selective transaminases in the kinetic resolution of racemic amines to produce pure (R)-amines.

Optimized expression and purification of a soluble BMP2 variant based on in-silico design.

Bone morphogenetic protein 2 (BMP2) is a highly interesting therapeutic growth factor due to its strong osteogenic/osteoinductive potential. However, its pronounced aggregation tendency renders recombinant and soluble production troublesome and complex. While prokaryotic expression systems can provide BMP2 in large amounts, the typically insoluble protein requires complex denaturation-renaturation procedures with medically hazardous reagents to obtain natively folded homodimeric BMP2.