3 publications
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Covalent Anchoring of a Racemization Catalyst to CALB-Beads: Towards Dual Immobilization of DKR Catalysts
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Tetrahedron Lett. 2011, 52, 1601-1604, 10.1016/j.tetlet.2011.01.106
The preparation of a heterogeneous bifunctional catalytic system, combining the catalytic properties of an organometallic catalyst (racemization) with those of an enzyme (enantioselective acylation) is described. A novel ruthenium phosphonate inhibitor was synthesized and covalently anchored to a lipase immobilized on a solid support (CALB, Novozym® 435). The immobilized bifunctional catalytic system showed activity in both racemization of (S)-1-phenylethanol and selective acylation of 1-phenylethanol.
Metal: RuHost protein: Lipase B from C. antarctica (CALB)Anchoring strategy: CovalentOptimization: ChemicalNotes: Lipase CALB is immobilized on a solid support (Novozym®435). Dynamic kinetic resolution (DKR) of 1-phenylethanol to the acylated product.
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Design and Evolution of New Catalytic Activity with an Existing Protein Scaffold
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Science 2006, 311, 535-538, 10.1126/science.1118953
The design of enzymes with new functions and properties has long been a goal in protein engineering. Here, we report a strategy to change the catalytic activity of an existing protein scaffold. This was achieved by simultaneous incorporation and adjustment of functional elements through insertion, deletion, and substitution of several active site loops, followed by point mutations to fine-tune the activity. Using this approach, we were able to introduce β-lactamase activity into the αβ/βα metallohydrolase scaffold of glyoxalase II. The resulting enzyme, evMBL8 (evolved metallo β-lactamase 8), completely lost its original activity and, instead, catalyzed the hydrolysis of cefotaxime with a (kcat /Km)app of 1.8 × 102 (mole/liter)–1 second–1, thus increasing resistance to Escherichia coli growth on cefotaxime by a factor of about 100.
Metal: ZnLigand type: Amino acidHost protein: Glyoxalase II (Human)Anchoring strategy: DativeOptimization: GeneticNotes: kcat/KM ≈ 184 M-1*s-1
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Supramolecular Enzyme Mimics
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Comprehensive Supramolecular Chemistry II 2017, 459-510, 10.1016/B978-0-12-409547-2.12551-X
Artificial metalloenzymes result from the incorporation of an organometallic moiety within a macromolecule. In this article, we review the field of artificial metalloenzymes. These are classified according to the host that accommodates the organometallic cofactor: cyclodextrins (“Cyclodextrin-Based Artificial Enzymes” section), ligands bearing a substrate recognition motif (“Artificial Enzymes With Ligands Bearing Substrate Recognition Motifs” section), supramolecular cages (“Cage Molecules as Artificial Enzymes” section), nucleic acids (“DNA-Based Artificial Metalloenzymes” section), and proteins (“Protein-Based Artificial Enzymes” section). Both dative and supramolecular anchoring strategies are reviewed.
Notes: Book chapter