Biochemical studies on a versatile esterase that is most catalytically active with polyaromatic esters.

ABSTRACT: Herein, we applied a community genomic approach using a naphthalene-enriched community (CN1) to isolate a versatile esterase (CN1E1) from the ?/?-hydrolase family. The protein shares low-to-medium identity (??57%) with known esterase/lipase-like proteins. The enzyme is most active at 25-30°C and pH?8.5; it retains approximately 55% of its activity at 4°C and less than 8% at ??55°C, which indicates that it is a cold-adapted enzyme. CN1E1 has a distinct substrate preference compared with other ?/?-hydrolases because it is catalytically most active for hydrolysing polyaromatic hydrocarbon (phenanthrene, anthracene, naphthalene, benzoyl, protocatechuate and phthalate) esters (7200-21?000?units?g(-1) protein at 40°C and pH?8.0). The enzyme also accepts 44 structurally different common esters with different levels of enantio-selectivity (1.0-55?000?units?g(-1) protein), including (±)-menthyl-acetate, (±)-neomenthyl acetate, (±)-pantolactone, (±)-methyl-mandelate, (±)-methyl-lactate and (±)-glycidyl 4-nitrobenzoate (in that order). The results provide the first biochemical evidence suggesting that such broad-spectrum esterases may be an ecological advantage for bacteria that mineralize recalcitrant pollutants (including oil refinery products, plasticizers and pesticides) as carbon sources under pollution pressure. They also offer a new tool for the stereo-assembly (i.e. through ester bonds) of multi-aromatic molecules with benzene rings that are useful for biology, chemistry and materials sciences for cases in which enzyme methods are not yet available.

SUBMITTER: Martinez-Martinez M 

PROVIDER: S-EPMC3937722 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature