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Future Strategies for Commercial Biocatalysis
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Robert E. Speight, Karen T. Robins
All steps of the sequential, one-pot chemoenzymatic syntheses of (D)-biarylalanines were carried out in aqueous solution (Fig. 1.7). The first step was the reductive animation of 4-bromophenylpyruvic acid with the NADPH-dependent enzyme, d-amino acid dehydrogenase (DAAD), followed by Boc-protection to prevent unwanted side-product formation and to ensure quantitative yields. The last step was a Suzuki–Miyauri coupling with selected arylboronic acid derivatives. The first step of the synthesis of N-boc-(D)-biarylalanine was the d-amino acid dehydrogenase step, which was carried out at room temperature (RT) and used the glucose dehydrogenase/glucose system for the regeneration of NADPH. 4-Bromophenylpyruvic acid was completely converted to 4-bromo-(d)-phenylalanine with an enantiomeric excess >99%. The next step was Boc-protection of the amine group and then the palladium-catalyzed Suzuki–Miyauri coupling of N-Boc-4-bromo-(D)-phenylalanine and phenylboronic acid to produce N-boc-(d)-biarylalanine. The overall conversion was 86% with an enantiomeric excess of >99% for the final product. The complete conversion of 4-bromophenylpyruvic acid ensured that there were no side-products formed in the subsequent steps and that the palladium catalysis was not inactivated. However, it was necessary to add tetrahydrofuran (THF) for the Boc-protection step, increase the concentration of the palladium catalyst and increase the temperature to 120°C for the Suzuki Miyauri coupling. Microwave irradiation (MW) was also applied to both chemical steps, to reduce the reaction time, in the case of the coupling step, from 24 h to 20 min. Chemoenzymatic synthesis of N-boc-(D)-biarylalanine.Adapted from Ahmed et al. (2015).
Metalloproteinases and NAD(P)H-dependent oxidoreductase within of Bay nettle (Chrysaora chesapeakei) venom
Published in Toxin Reviews, 2022
Mayra Pamela Becerra-Amezcua, Mónica Alejandra Rincón-Guevara, Irma Hernández-Calderas, Xochitl Guzmán-García, Isabel Guerrero-Legarreta, Humberto González-Márquez
The protein of approx. 37 kDa is a NAD(P)/FAD-dependent oxidoreductase, although oxidoreductases have been detected in the jellyfish C. fuscescens (Ponce et al.2016), N. nomurai (Yue et al.2017b) and Cyanea sp. (Liang et al.2019), little is known about its effects. L-amino acid oxidases (LAAOs) had been found in venoms of snakes. These enzymes belong to the family called NAD(P)/FAD-dependent oxidoreductase that also comprises polyamine oxidase (PAO), flavin-containing monoamine oxidases (MAOs), D-amino acid dehydrogenase, and linoleic acid isomerase. Moreover, have various pathological and physiological activities, including induction of apoptosis, edema, platelet aggregation/inhibition, hemorrhagic, and anticoagulant activities (Ullah 2020). In general, the LAAOs are homodimers with molecular masses ranging from 120 to 150 kDa in their native form and 50 to 70 kDa in their monomeric forms (Costa et al.2014), but in jellyfish, homology with these enzymes has been found in proteins with smaller molecular weights (45–18 kDa) (Yue et al.2017b), which could indicate that in these organisms these enzymes are smaller.