Sphingomonas wittichii RW1 is a bacterium which has been
shown to have the ability to degrade polychlorinated dioxins, and hence has had
its genome fully sequenced. It has two different nitrilases in its
genome.
Two papers just released with the corresponding authors Er-Zheng
Su and Dong-Zhi Wei report on the nitrilase with the accession code YP_001264656.
These authors and enzyme have previously been mentioned on this blog- I complained there was no information on the enzyme discovery... here it is!
The first entitled “Cloning, Overexpression, andCharacterization of a High Enantioselective Nitrilase from Sphingomonaswittichii RW1 for Asymmetric Synthesis of (R)-Phenylglycine” and published in Applied
Biochemistry and Biotechnology: Part A: Enzyme Engineering and Biotechnology describes
the construction of a mini-library of nitrilase enzymes chosen by the
similarity to a nitrilase from Pseudomonas fluorescens EBC191 (GenBank accession no. AAW79573) which has been
shown to be highly activity toward phenylglycinonitrile. The nitrilase from Sphingomonas
wittichii RW1 was shown to be most promising nitrilase to achieve chiral
synthesis of R-phenylglycine in a kinetic resolution mode.
The second entitled “Efficient asymmetric synthesis ofD-N-formyl-phenylglycine via cross-linked nitrilase aggregates catalyzeddynamic kinetic resolution” and published in Catalysis Communications describes
the preparation of cross-linked enzyme aggregates (CLEAs) of nitrilase from
Sphingomonas wittichii RW1, and then its use to perform dynamic kinetic
resolution to make D-N-formyl-phenylglycine. The paper also demonstrates that
the CLEAs have improved stability over non-immobilized enzyme and are reuseable
up to six times whilst retaining 70% initial activity.
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