3,4-Dihydrocoumarin Hydrolase from Thermophilic Geobacillus sp Strain

作者：Giedraityte G^*; Kalediene L

来源：Romanian Biotechnological Letters, 2012, 17(2): 7104-7113.

• Geobacillus
• 1-naphthol
• purification
• 3,4-dihydrocoumarin hydrolase

3,4- Dihydrocoumarin hydrolase (EC 3.1. 1. 35) was purified 186- fold to apparent homogeneity, with a 2.9 % overall recovery, from Geobacillus sp. G27, which was isolated as a 1- naphthol assimilating microorganism. The purification procedure included ammonium sulfate fractionation and column chromatographies on DEAE-cellulose and Sephadex G- 75. The molecular mass of native hydrolase, as estimated by gel chromatography, was 70 kDa, and the subunit molecular mass was 30 kDa on SDS-polyacrylamide gel electrophoresis. The enzyme specifically hydrolyzes 3,4- dihydrocoumarin, and the K-m and V-max for 3,4 - dihydrocoumarin were 0.996 mM and 2320 U mg(-1), respectively. Aromatic lactones, such as 2- coumaranone and gentisic acid lactone, also serve as substrates, but their susceptibilities relative to that of dihydrocoumarin are quite low. The pH and temperature optima for enzyme activity were 7 and 60 degrees C, respectively. The inactivation rate constant at 60 degrees C was 14.2.10(-3) min(-1). The half-life of the enzyme at optimum temperature was 55 min.

• 出版日期2012-4