Purification and characterization of a novel nitrile hydratase from Rhodococcus sp. RHA1.

摘要: The microbial degradation of nitriles is interest for bioremediation and green chemistry. We demonstrated that the soil bacterium Rhodococcus sp. RHA1 utilizes a range nitriles, including acetonitrile, as growth substrates. Proteomic analysis identified 13 proteins were more abundant in acetonitrile-grown cells, an aliphatic amidase protein with no known homologue. Purification nitrile hydratase (NHase) from cells unknown beta subunit two-subunit NHase. Sequence revealed genes encoding (anhC) NHase (anhAB) occur 12.8 kbp cluster located on plasmid pRHL2. anh gene also encodes acetyl-CoA hydrolase, transcriptional regulators, putative cobalt transporter function. Striking features include amino acid sequence identity (32%) large size (63 56 kDa) alpha subunits, well enzyme's metal ion content (one cobalt, two copper one zinc). enzyme possessed similar specificities acetonitrile propionitrile (k(cat)/K(m) approximately 7 mM(-1) s(-1)) followed by acrylonitrile butyronitrile. propose this (ANHase) represents first member previously class NHases.