Nitrile-synthesizing enzyme: Screening, purification and characterization.
J Gen Appl Microbiol
; 62(4): 167-73, 2016 Sep 12.
Article
em En
| MEDLINE
| ID: mdl-27250663
ABSTRACT
Cyanide is known as a toxic compound for almost all living organisms. We have searched for cyanide-resistant bacteria from the soil and stock culture collection of our laboratory, and have found the existence of a lot of microorganisms grown on culture media containing 10 mM potassium cyanide. Almost all of these cyanide-resistant bacteria were found to show ß-cyano-L-alanine (ß-CNAla) synthetic activity. ß-CNAla synthase is known to catalyze nitrile synthesis:
the formation of ß-CNAla from potassium cyanide and O-acetyl-L-serine or L-cysteine. We found that some microorganisms were able to detoxify cyanide using O-methyl-DL-serine, O-phospho-L-serine and ß-chloro-DL-alanine. In addition, we purified ß-CNAla synthase from Pseudomonas ovalis No. 111 in nine steps, and characterized the purified enzyme. This enzyme has a molecular mass of 60,000 and appears to consist of two identical subunits. The purified enzyme exhibits a maximum activity at pH 8.5-9.0 at an optimal temperature of 40-50°C. The enzyme is specific for O-acetyl-L-serine and ß-chloro-DL-alanine. The Km value for O-acetyl-L-serine is 10.0 mM and Vmax value is 3.57 µmol/min/mg.
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Base de dados:
MEDLINE
Assunto principal:
Pseudomonas
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Cianetos
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Alanina
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Liases
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Nitrilas
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article