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Late‐stage functionalization of lead compounds is of high interest in drug discovery since it offers an easy access to metabolites and derivatives of a lead compound without the need to redesign an often long multistep synthesis. Owing to their high degree of chemoselectivity, biocatalytic transformations, enzymatic oxidations in particular, are potentially very powerful because they could allow the synthesis of less lipophilic derivatives of a lead compound. In the majority of cases, enzymatic oxidations have been used in an empirical way as their regioselectivity is difficult to predict. In this publication, the concept of using docking/protecting groups in a biomimetic fashion was investigated, which could help steer the regioselectivity of a P450BM3‐mediated oxidation. A novel set of docking/protecting groups was designed that can be cleaved under very mild conditions and address the often problematic aqueous solubility of the substrates. Vabicaserin was used as tool compound containing typical groups such as basic, aliphatic, and aromatic moieties. The results were rationalized with the help of in silico docking and molecular dynamic studies. Novel solubilizing docking‐protecting groups enable the regioselective P450BM3‐mutant mediated late‐stage oxidation of lead compounds by binding the substrate (orange) in a biomimetic fashion (e.g. palmitic acid, green). Enzymatic oxidation, mild deprotection and purification yields hydroxylated derivatives that are difficult to obtain by classical chemical synthesis. [ABSTRACT FROM AUTHOR]

The NewProt protein engineering portal is a one-stop-shop for in silico protein engineering. It gives access to a large number of servers that compute a wide variety of protein structure characteristics supporting work on the modification of proteins through the introduction of (multiple) point mutations. The results can be inspected through multiple visualizers. The HOPE software is included to indicate mutations with possible undesired side effects. The Hotspot Wizard software is embedded for the design of mutations that modify a proteins' activity, specificity, or stability. The NewProt portal is freely accessible at http://newprot.cmbi.umcn.nl/ and http://newprot.fluidops.net/. [ABSTRACT FROM AUTHOR]

Chiral amines are important building blocks, especially for the pharmaceutical industry. Although amine transaminases (ATAs) are versatile enzymes to synthesize chiral amines, the wildtype enzymes do not accept ketones with two large substituents next to the carbonyl functionality. Using bioinformatic tools to design a seven-site mutant library followed by high-throughput screening, we were able to identify variants of the enzyme from Vibrio fluvialis (VF-ATA) with a widened binding pocket, as exemplified for a range of ketones. Three variants allowed the asymmetric synthesis of 2,2-dimethyl-1-phenylpropan-1-amine-not accessible by any wildtype ATA described so far. The best variant containing four mutations (L56V, W57C, F85V, V153A) gave 100 % conversion of the ketone to yield the amine with an enantiomeric excess value >99 %, notably with preference for the ( R)-enantiomer. In silico modeling enabled the reconstruction of the substrate binding mode to the newly evolved pocket and, hence, allowed explanation of the experimental results. [ABSTRACT FROM AUTHOR]

ABSTRACT A fully automatized robotic platform has been established to facilitate high-throughput screening for protein engineering purposes. This platform enables proper monitoring and control of growth conditions in the microtiter plate format to ensure precise enzyme production for the interrogation of enzyme mutant libraries, protein stability tests and multiple assay screenings. The performance of this system has been exemplified for four enzyme classes important for biocatalysis such as Baeyer-Villiger monooxygenase, transaminase, dehalogenase and acylase in the high-throughput screening of various mutant libraries. This allowed the identification of novel enzyme variants in a sophisticated and highly reliable manner. Furthermore, the detailed optimization protocols should enable other researchers to adapt and improve their methods. Biotechnol. Bioeng. 2016;113: 1421-1432. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

To alter the amine donor/acceptor spectrum of an (S)-selective amine transaminase (ATA), a library based on the Vibrio fluvialis ATA targeting four residues close to the active site (L56, W57, R415 and L417) was created. A 3DM-derived alignment comprising fold class I pyridoxal-51-phosphate (PLP)-dependent enzymes allowed identification of positions, which were assumed to determine substrate specificity. These positions were targeted for mutagenesis with a focused alphabet of hydrophobic amino acids to convert an amine:α-keto acid transferase into an amine:aldehyde transferase. Screening of 1200 variants revealed three hits, which showed a shifted amine donor/acceptor spectrum towards aliphatic aldehydes (mainly pentanal), as well as an altered pH profile. Interestingly, all three hits, although found independently, contained the same mutation R415L and additional W57F and L417V substitutions. [ABSTRACT FROM AUTHOR]

One lock for different keys: A flexible arginine in the active site allows γ‐aminobutyrate:pyruvate transaminases to bind the chemically different substrates L‐alanine and γ‐aminobutyric acid. Moreover, a flexible arginine residue facilitates the promiscuous conversion of (S)‐amines and ketones. The degree of promiscuity can be related to distinct key amino acids lying at the surface of the active site. [ABSTRACT FROM AUTHOR]

Digging in the database: Four synthetically useful transaminases for which no function was known were studied by evaluating a set of eight amino donors and seven acceptors (see figure). The four enzymes differ substantially in their catalytic properties and substrate preferences. We also used the enzymes in the asymmetric synthesis of a range of chiral amines and observed excellent enantioselectivities and conversions. [ABSTRACT FROM AUTHOR]

The first published synthesis of unprotected carboxy indazoles from the corresponding bromoindazoles is described. This is achieved via Pd(II)-catalyzed carbonylation and is demonstrated to work on a variety of indazoles. [ABSTRACT FROM PUBLISHER]

Combining biocatalytic oxidation with protective‐group chemistry enables one to modulate the site of oxidation. Lead compounds protected with different solubilizing biomimetic docking/protecting groups yield different hydroxylated derivatives with the same P450BM3‐mutant. Additional hydroxylation products are obtained when the P450BM3‐mutant is also varied. Derivatives of this type are difficult to obtain otherwise. Additionally, molecular‐dynamic simulations help to rationalize the observed oxidation patterns. For more information, see the Full Paper by U. E. W. Lange et al. on page 17936 ff. [ABSTRACT FROM AUTHOR]