Purification and biochemical characterization of the carbamate hydrolase from Pseudomonas sp. 50432.
A soluble carbamate hydrolase that had a wide specificity was purified 2032-fold from Pseudomonas sp. 50432. This was achieved using a combination of anion-exchange, gel-filtration and hydrophobic-interaction- chromatography techniques. Carbamate hydrolase cleaved the ester linkage of the N-methylcarbamates. The native enzyme was a monomer with a molecular mass of 88 kDa. The optimum pH and temperature of the enzyme activity were 8.5 and 37 degrees C respectively. The tested cations or EDTA did not affect the enzyme activity. However, 2-mercaptoethanol reversibly inhibited the enzyme activity. The enzyme showed the K(m) values of 16 and 12 microM for carbofuran and carbaryl respectively. The purified enzyme did not hydrolyse o-nitrophenyl dimethylcarbamate but hydrolysed several N-methylcarbamates and 1-naphthyl acetate.
Chaudhry
G Rasul
GR
Department of Biological Sciences, 327 SEB, Oakland University, Rochester, MI 48309-4401, U.S.A. chaudhry@oakland.edu
Mateen
A
A
Kaskar
B
B
Bloda
M
M
Riazuddin
Sheikh
S
D002219:Carbamates / Q000737:chemistry*; D002235:Carbofuran / Q000737:chemistry*; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008623:Mercaptoethanol / Q000494:pharmacology; D008956:Models, Chemical; D008970:Molecular Weight; D011549:Pseudomonas / Q000145:classification / Q000201:enzymology*; D012680:Sensitivity and Specificity; D013696:Temperature
D002219:Carbamates; D008623:Mercaptoethanol; C020401:N-methylcarbamate; D002265:Carboxylic Ester Hydrolases; C077242:carbamate hydrolase; D002235:Carbofuran