A gene coding for an esterase (EstEH112) was isolated from metagenome originated from Korean intertidal flat sediment. The putative esterase gene encoded a 340 amino acids protein with characteristic residues of lipolytic enzymes such as a conserved pentapeptide (GXSXG), the typical catalytic S-D-H triad, and a GGG(A)X-motif in the oxyanion hole near the active site similar to the hormone sensitive lipase (HSL) family. p-Nitrophenyl butyrate was the best substrate for the enzyme among the other p-nitrophenyl esters investigated. The apparent optimal temperature and pH for EstEH112 was 35 C and at pH 8.0, respectively. EstEH112 efficiently catalyzed the hydrolysis of various large tertiary alcohol esters. These characteristics of EstEH112 make it a potential candidate for application in biocatalysis. (C) 2012 Elsevier B.V. All rights reserved.
Kinetic resolution of esters from secondary and tertiary benzylic propargylic alcohols by an improved esterase-variant from Bacillus sp. BP-7
作者:Amanda Fillat、Pedro Romea、F.I. Javier Pastor、Fèlix Urpí、Pilar Diaz
DOI:10.1016/j.cattod.2014.12.041
日期:2015.10
enantiomeric resolution of acetate esters of tertiaryalcohols. Variant EstBP7-AGA, bearing two aminoacidic changes in the oxyanion hole, showed an excellent E > 100 enantioselectivity value towards a complex tertiaryalcohol acetate (2-(4-pyridyl)-3-butyn-2-yl acetate) at low reaction temperature (4 °C). We here go further in the investigation of such esterase variant by analyzing the kinetic resolution of