ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Rhodococcus equi Ac6 was found to express an inducible (S )-specific N-acetyl-1-phenylethylamine amidohydrolase. Optimal bacterial growth and amidohydrolase expression were both observed around pH 6.5. Purification of the enzyme to a single band in a Coomassie-blue-stained sodium dodecyl sulfate/polyacrylamide gel (SDS-PAGE) was achieved by ammonium sulfate precipitation of R. equi Ac6 crude extract and column chromatographies on Fractogel TSK Butyl-650(S) and Superose 12HR. At pH 7.0 and 30 °C the amidohydrolase had a half-life of around 350 days; at 44 °C it was only 10 min. Except for Ni2+ and, to some extent, Zn2+ and Co2+, the enzyme was neither strongly influenced by metal cations nor by chelating agents, but was inhibited by 95% at 0.1 mM phenylmethylsulfonyl fluoride. The molecular mass of the native enzyme was estimated to be 94 kDa by gel filtration and 50 kDa by SDS-PAGE, suggesting a dimeric structure. Specificity experiments revealed a spectrum of related N-acetylated compounds being hydrolyzed with variable enantiomeric selectivities.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002530050965
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