title: Purification and characterization of an erythromycin esterase from an erythromycin-resistant Pseudomonas sp.
abstract: An erythromycin esterase (molecular mass 51200 Da) was purified from Pseudomonas sp. GD100, which was isolated from a salmon hatchery sediment sample from Washington State. The pI of the protein was 4.5-4.8. The enzyme was inhibited by 1 mM mercuric acid, and had the substrate specificity for structurally related 14-membered macrolides, which decreased in the order of oleandomycin, erythromycin A and erythromycin A enol ether. The activity for erythromycin A varied with temperature, but the effect of pH was minimal at pH 6.0-9.0. The half-life of the enzyme was estimated to be 8.9 h at 35 degrees C and 0.23 h at 55 degrees C, and the activation energy of the catalytic reaction of erythromycin A was estimated at 16.2 kJ mol(-1).
authors.affiliation: Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Rd, Jefferson, AR 72079, USA.
authors.forename: Yong-Hak
authors.initials: YH
authors.lastname: Kim
authors.forename: Chang-Jun
authors.initials: CJ
authors.lastname: Cha
authors.forename: Carl E
authors.initials: CE
authors.lastname: Cerniglia
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004917:Erythromycin / Q000378:metabolism / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008970:Molecular Weight; D009827:Oleandomycin / Q000378:metabolism; D011549:Pseudomonas / Q000187:drug effects* / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D004917:Erythromycin; D002265:Carboxylic Ester Hydrolases; C046388:erythromycin esterase; D009827:Oleandomycin