Nitrile active enzyme posters

We are at Biotrans 2013 in Manchester this week. Whilst it has to be said that transaminases is the most frequently described enzyme type described here, there are a few posters describing nitrile active enzymes.
Nicola D'Antona has a poster entitled "Biotransformations of nitrile ferrocenes catalyzed by the bienzymatic system of nitrile hydratase/amidase: first examples of molecular recognition and enantioselectivity of chiral planar substrates". This poster describes the use of a couple of Rhodococcus species to hydrate and hydrolyze either one or two cyano groups appended to the double decker ferrocene sandwich. Considering NHases' dislike of bulky substrates that is a neat discovery. They even get some enantioselectivity especially in the acids where the amidase in the whole cell is strongly selective in determining the sterics of the outcome.
Birgit Wilding has a poster entitled "Enantioselective synthesis of a taxol side chain precursor with bacterial and fungal nitrilases". Obviously finding a biocatalytic way to build even a portion of a pharmaceutical is a great demonstration of using this technology to provide a green and inherently stereoselective route for the commercial arena. An interesting finding reported on this poster is the tendency of the bacterial nitrilases (two of which came from our Nzomics panel) in her panel to serve up not just the acid but the primary amide of her side chain precursors too. The ratio of amide to acid is sensitive to substrate concentration... Intriguing- I had one person previously complain about getting amide when they wanted acid with one of these enzymes but I don't know what their substrate was!
Cintia Milagre is displaying a poster called "Synthesis of alkyl and aryl substituted amides by nitrile hydratases" summarizing work on nitrile hydratase discovery from Brazilian soil samples and their utility at hydrating alpha substituted nitriles.
Carine Vergne-Vaxelaire is displaying a poster entitled "Biocatalytic tools for organic chemists: new nitrilases for synthesis of building blocks" which outlines the high throughput screening of 125 nitrilases against 25 structurally diverse nitriles, and is linked to a lecture being given later in the week by Anne Zaparucha.
Sander van Pelt has a poster called "Nitrile Hydratases: from genes to immobilized biocatalyst" highlighting the extra utility that a covalently linked enzyme aggregate preparation from CLEA Technologies has in terms of stability. It is nice to see that the NHases from AJ270 and CGA009 that we have worked on together are still useful examples in this field.
Finally hiding undercover at P387 is our poster on nitrilases. Graeme Turnbull has written up his semi-quantitative colorimetric methodology for assaying the activity of nitrilases as cell-free extracts (which screw up a pH driven colorimetric method) and then showing how he has applied it to a panel of 14 enzymes and 40 diverse substrates.

Methods of immobilization of NHase, and a new one.

There is a new paper on the immobilization of nitrile hydratase to give greater stability. There are a few previous examples of this topic including:

·         Nitrile hydratase CLEAs: The immobilization and stabilization of an industrially important enzyme from Sander van Pelt, Sandrine Quignard, David Kubac, Dimitry Y. Sorokin, Fred van Rantwijk and Roger A. Sheldon in Green Chemistry in 2008. (DOI: 10.1039/b714258g)

·         Production of Acrylamide using Alginate-Immobilized E. coli Expressing Comamonas testosteroni 5-MGAM-4D Nitrile Hydratase from Lawrence J. Mersinger, Eugenia C. Hann, Frederick B. Cooling, John E. Gavagan, Arie Ben-Bassat, Shijun Wu, Kelly L. Petrillo, Mark S. Payne, and Robert DiCosimo in Advanced Synthesis and Catalysis in 2005. (DOI: 10.1002/adsc.200505039)

·         Biotransformation of nitriles by Rhodococcus equi A4 immobilized in LentiKats from David Kubáč, Alena Čejková, Jan Masák, Vladimír Jirků, Marielle Lemaire, Estelle Gallienne, Jean Bolte, Radek Stloukal, Ludmila Martínková in Journal of Molecular Catalysis B: Enzymatic in 2006. (doi:10.1016/j.molcatb.2006.01.004)

This one is Catalytic Properties of a Nitrile Hydratase Immobilized on Activated Chitosan by Yu. G. Maksimova, T. A. Rogozhnikova, G. V. Ovechkina, A. Yu. Maksimov, and V. A. Demakov in Applied Biochemistry and Microbiology (DOI: 10.1134/S0003683812030076).

They have used a nitrile hydratase isolated from a strain of Rhodococcus ruber gt1 and immobilized it on chitosan activated with 0.1% benzoquinone solution. They show that this immobilized enzyme can be used for 50 consecutive cycles of acrylonitrile transformation with activity holding up well.

They also found that their immobilized nitrile hydratases remain active at pH 3.0–4.0 which usefully extends its effective pH range.

More on the industrial exploitation of Nitrile Hydratases

I have just been pointed in the direction of a rather nice summary ("Nitrile hydratases in synthesis") of the state of play for nitrile hydratase commercial exploitation from the May/June 2008 issue of Chemistry Today from Sander van Pelt. It includes more details of the Mitsubishi Rayon, Lonza, and DuPont usage, and shows how SNF Floerger were looking to introduce biocatalytic acrylamide production to Europe.