Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Weissenborn, M. J.; Notonier, S.; Lang, S.-L.; Otte, K. B.; Herter, S.; Turner, N. J.; Flitsch, S. L.; Hauer, B.;Whole-cell microtiter plate screening assay for terminal hydroxylation of fatty acids by P450sChem. Commun.526158-6161(2016)DOI: 10.1039/C6CC01749E
A readily available galactose oxidase (GOase) variant was used to develop a whole cell screening assay. This endpoint detection system was applied in a proof-of-concept approach by screening a focussed mutant library. This led to the discovery of the thus far most active P450 Marinobacter aquaeolei mutant catalysing the terminal hydroxylation of fatty acids.
Publikation
Weissenborn, M. J.; Löw, S. A.; Borlinghaus, N.; Kuhn, M.; Kummer, S.; Rami, F.; Plietker, B.; Hauer, B.;Enzyme-Catalyzed Carbonyl Olefination by the E. coli Protein YfeX in the Absence of PhosphinesChemCatChem81636-1640(2016)DOI: 10.1002/cctc.201600227
The Wittig‐type carbonyl olefination reaction has no biocatalytic equivalent. To build complex molecular scaffolds, however, C−C bond‐forming reactions are pivotal for biobased economy and synthetic biology. The heme‐containing E. coli protein YfeX was found to catalyze carbonyl olefination by reaction of benzaldehyde with ethyl diazoacetate under aerobic conditions in the absence of a triphenylphosphine oxophile. The reaction was performed in whole cells and showed a product formation of 440 mg L−1 in 1 h. It was, moreover, shown that the reaction could be performed under Wittig‐analogue conditions in the presence of triphenylphosphine or triphenylarsine.
Publikation
Löw, S. A.; Löw, I. M.; Weissenborn, M. J.; Hauer, B.;Enhanced Ene-Reductase Activity through Alteration of Artificial Nicotinamide Cofactor SubstituentsChemCatChem8911-915(2016)DOI: 10.1002/cctc.201501230
The reduction of activated C=C double bonds is an important reaction in synthetic chemistry owing to the potential formation of up to two new stereogenic centers. Artificial nicotinamide cofactors were recently presented as alternative suppliers of hydride equivalents needed for alkene reduction. To study the effect of cofactors on the reduction of activated alkenes, a set of N‐substituted synthetic nicotinamide cofactors with differing oxidation potentials were synthesized and their electrochemical and kinetic behavior was studied. The effects of the synthetic cofactors on enzyme activity of four ene reductases are outlined in this study, where the cofactor mimic with an N‐substituted 4‐hydroxy‐phenyl residue led to a sixfold higher vmax relative to the natural cofactor NADH.
Publikation
Llaudet, E. C.; Darimont, D.; Samba, R.; Matiychyn, I.; Stelzle, M.; Weissenborn, M. J.; Hauer, B.;Expanding an Efficient, Electrically Driven and CNT-Tagged P450 System into the Third Dimension: A Nanowired CNT-Containing and Enzyme-Stabilising 3 D Sol-Gel ElectrodeChemBioChem171367-1373(2016)DOI: 10.1002/cbic.201600173
Although electrochemically catalysed P450 reactions have been described, their efficiency and applicability remained limited. This is mostly due to low enzyme activity, laborious protein immobilisation and the small electrode surface. We established a novel protein immobilisation method for a determined orientation and electrical wiring of the enzyme without post‐expression modification. By genetic introduction of an anchor‐peptide our method is applicable for screening medium to large mutant libraries and detection by an electrode system. The system was expanded by using wired carbon nanotubes within a sol‐gel matrix to create a three dimensional electrode.