Characterization of a thermostable D-stereospecific alanine amidase from Brevibacillus borstelensis BCS-1.
Appl Environ Microbiol
; 69(2): 980-6, 2003 Feb.
Article
em En
| MEDLINE
| ID: mdl-12571020
ABSTRACT
A gene encoding a new thermostable D-stereospecific alanine amidase from the thermophile Brevibacillus borstelensis BCS-1 was cloned and sequenced. The molecular mass of the purified enzyme was estimated to be 199 kDa after gel filtration chromatography and about 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the enzyme could be composed of a hexamer with identical subunits. The purified enzyme exhibited strong amidase activity towards D-amino acid-containing aromatic, aliphatic, and branched amino acid amides yet exhibited no enzyme activity towards L-amino acid amides, D-amino acid-containing peptides, and NH(2)-terminally protected amino acid amides. The optimum temperature and pH for the enzyme activity were 85 degrees C and 9.0, respectively. The enzyme remained stable within a broad pH range from 7.0 to 10.0. The enzyme was inhibited by dithiothreitol, 2-mercaptoethanol, and EDTA yet was strongly activated by Co(2+) and Mn(2+). The k(cat)/K(m) for D-alaninamide was measured as 544.4 +/- 5.5 mM(-1) min(-1) at 50 degrees C with 1 mM Co(2+).
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estereoisomerismo
/
Bacillus
/
Alanina
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Amidoidrolases
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Temperatura Alta
Idioma:
En
Revista:
Appl Environ Microbiol
Ano de publicação:
2003
Tipo de documento:
Article