Biocatalysis — key to sustainable industrial chemistry

This critical review presents an introduction to biocatalysis for synthetic chemists. Advances in biocatalysis of the past 5 years illustrate the breadth of applications for these powerful and selective catalysts in conducting key reaction steps. Asymmetric synthesis of value-added targets and other reaction types are covered, with an emphasis on pharmaceutical intermediates and bulk chemicals. Resources of interest for the non-initiated are provided, including specialized websites and service providers to facilitate identification of suitable biocatalysts, as well as references to recent volumes and reviews for more detailed biocatalytic procedures. Challenges related to the application of biocatalysts are discussed, including how ‘green’ a biocatalytic reaction may be, and trends in biocatalyst improvement through enzyme engineering are presented (152 references).

Expanding the organic toolbox: a guide to integrating biocatalysis in synthesis.

l-Amino acid oxidase (LAAO) is a flavoenzyme containing non-covalently bound flavin adenine dinucleotide, which catalyzes the stereospecific oxidative deamination of l-amino acids to α-keto acids and also produces ammonia and hydrogen peroxide via an imino acid intermediate. LAAOs purified from snake venoms are the best-studied members of this family of enzymes, although a number of LAAOs from bacterial and fungal sources have been also reported. From a biochemical point of view, LAAOs from different sources are distinguished by molecular mass, substrate specificity, post-translational modifications and regulation. In analogy to the well-known biotechnological applications of d-amino acid oxidase, important results are expected from the availability of suitable LAAOs; however, these expectations have not been fulfilled yet because none of the “true” LAAOs has successfully been expressed as a recombinant protein in prokaryotic hosts, such as Escherichia coli. In enzyme biotechnology, recombinant production of a protein is mandatory both for the production of large amounts of the catalyst and to improve its biochemical properties by protein engineering. As an alternative, flavoenzymes active on specific l-amino acids have been identified, e.g., l-aspartate oxidase, l-lysine oxidase, l-phenylalanine oxidase, etc. According to presently available information, amino acid oxidases with “narrow” or “strict” substrate specificity represent as good candidates to obtain an enzyme more suitable for biotechnological applications by enlarging their substrate specificity by means of protein engineering.

L-Amino acid oxidase as biocatalyst: a dream too far?

Hydroxynitrile lyases are valuable enzymes for asymmetric synthesis of cyanohydrins. These hydroxyl and nitrile–containing compounds are being used in production of very useful pharmaceuticals, agrochemicals, and other biologically active compounds using chemical or chemoenzymatic follow-up reactions in industry. Although a huge amount of information exists on the reaction parameters of these enzymes, including stability to pH and organic solvents, yield, reaction time, and valuable data on the enantiopurity of their products, cyanohydrins, there is a lack of update on the biochemistry, discovery, and engineering of the HNLs. Therefore, in the Introduction, we will have a look into these enzymes, cyanohydrins, and aldoxime-nitrile pathways. A brief view of functional groups and several examples of cyanohydrin-based chemicals and pharmaceuticals will also be described. Then we will present characteristics of many S- and R-selective HNLs with comparative tables for several enzymatic properties under biochem...

Hydroxynitrile Lyases: Insights into Biochemistry, Discovery, and Engineering

Haloaromatic antimicrobial triclocarban (3,4,4′-trichlorocarbanilide, TCC) is a refractory contaminant which is frequently detected in various aquatic and sediment environments globally. However, few TCC-degrading communities or pure cultures have been documented, and functional enzymes involved in TCC biodegradation hitherto have not yet been characterized. In this study, a bacterial strain, Ochrobactrum sp. TCC-2, capable of degrading TCC under both aerobic and anaerobic conditions was isolated from a sediment sample. A novel amidase gene (tccA), responsible for the hydrolysis of the two amide bonds of TCC and its dehalogenated congeners 4,4′-dichlorocarbanilide (DCC) and carbanilide (NCC) to more biodegradable chloroaniline or aniline products, was cloned and characterized. TccA shares low amino acid sequence identity (27 to 38%) with other biochemically characterized amidases and contains the conserved catalytic triad (Ser-Ser-Lys) of the amidase signature enzyme family. TccA was stable over a pH rang...

Functional Characterization of a Novel Amidase Involved in Biotransformation of Triclocarban and its Dehalogenated Congeners in Ochrobactrum sp. TCC-2

PmHNL, a hydroxynitrile lyase from Japanese apricot ume (Prunus mume) seed was purified to homogeneity by ammonium sulfate fractionation and chromatographic steps. The purified enzyme was a monomer with molecular mass of 58 kDa. It was a flavoprotein similar to other hydroxynitrile lyases of the Rosaceae family. It was active over a broad temperature, and pH range. The N-terminal amino acid sequence (20 amino acids) was identical with that of the enzyme from almond (Prunus dulcis). Based on the N-terminal sequence of the purified enzyme and the conserved amino acid sequences of the enzymes from Pr. dulcis, inverse PCR method was used for cloning of a putative PmHNL (PmHNL2) gene from a Pr. mume seedling. Then the cDNA for the enzyme was cloned. The deduced amino acid sequence was found to be highly similar (95%) to that of an enzyme from Pr. serotina, isozyme 2. The recombinant Pichia pastoris transformed with the PmHNL2 gene secreted an active enzyme in glycosylated form.

https://www.tandfonline.com/doi/pdf/10.1271/bbb.100187

Characterization of a New (R)-Hydroxynitrile Lyase from the Japanese Apricot Prunus mume and cDNA Cloning and Secretory Expression of One of the Isozymes in Pichia pastoris

Several ω-laurolactam degrading microorganisms were isolated from soil samples These strains were capable of growing in a medium containing ω-laurolactam as sole source of carbon and nitrogen Among them, five strains (T7, T31, U124, U224, and U238) were identified as Cupriavidus sp T7, Acidovorax sp T31, Cupriavidus sp U124, Rhodococcus sp U224, and Sphingomonas sp U238, respectively The ω-laurolactam hydrolyzing enzyme from Rhodococcus sp U224 was purified to homogeneity, and its enzymatic properties were characterized The enzyme acts on ω-octalactam and ω-laurolactam, but other lactam compounds, amides and amino acid amides, cannot be substrates The enzyme gene was cloned, and the deduced amino acid sequence showed high homology with 6-aminohexanoate-cyclic-dimer hydrolase (EC 35212) from Arthrobacter sp KI72 and Pseudomonas sp NK87 Enzymatic synthesis of 12-aminolauric acid was performed using partially purified ω-laurolactam hydrolase from Rhodococcus sp U224

https://www.tandfonline.com/doi/pdf/10.1271/bbb.80210

The Screening, Characterization, and Use of ω-Laurolactam Hydrolase : A New Enzymatic Synthesis of 12-Aminolauric Acid

Purification and characterization of an L-amino acid oxidase from Pseudomonas sp. AIU 813.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/j.fob.2014.02.002

Mutational and crystallographic analysis of l-amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813: Interconversion between oxidase and monooxygenase activities.

Yasuhisa Fukuta

Papers

Characterization of a New (R)-Hydroxynitrile Lyase from the Japanese Apricot Prunus mume and cDNA Cloning and Secretory Expression of One of the Isozymes in Pichia pastoris

The Screening, Characterization, and Use of ω-Laurolactam Hydrolase : A New Enzymatic Synthesis of 12-Aminolauric Acid

Purification and characterization of an L-amino acid oxidase from Pseudomonas sp. AIU 813.

Mutational and crystallographic analysis of l-amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813: Interconversion between oxidase and monooxygenase activities.

A new aryl acylamidase from Rhodococcus sp. strain Oct1 acting on ω-lactams: Its characterization and gene expression in Escherichia coli