title: 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 α/β-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 α/β-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.
authors.affiliation: Department of Applied Biocatalysis, Consejo Superior de Investigaciones Científicas (CSIC), Institute of Catalysis, Marie Curie 2, 28049, Madrid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Martínez-Martínez
authors.forename: Iván
authors.initials: I
authors.lastname: Lores
authors.forename: Carlina
authors.initials: C
authors.lastname: Peña-García
authors.forename: Rafael
authors.initials: R
authors.lastname: Bargiela
authors.forename: Dolores
authors.initials: D
authors.lastname: Reyes-Duarte
authors.forename: María-Eugenia
authors.initials: ME
authors.lastname: Guazzaroni
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Peláez
authors.forename: Jesús
authors.initials: J
authors.lastname: Sánchez
authors.forename: Manuel
authors.initials: M
authors.lastname: Ferrer
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D016000:Cluster Analysis; D004795:Enzyme Stability; D004950:Esterases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006841:Hydrocarbons, Aromatic / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D011091:Polyesters / Q000378:metabolism*; D017385:Sequence Homology; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D006841:Hydrocarbons, Aromatic; D011091:Polyesters; D004950:Esterases