title: Purification and characterization of two extracellular lipases from Pseudomonas aeruginosa Ps-x.
abstract: Two different extracellular lipases were isolated and purified from Pseudomonas aeruginosa Ps-x to apparent homogeneity using ammonium sulfate precipitation followed by ion exchange chromatography on Q- and S-Sepharose column. Both of the purified lipases are monomeric protein with molecular weight of 15.5 and 54.97 KDa respectively. The optimal activities of the enzymes were at 45 and 50 degrees C and pHs 10.0 and 9.0. Calcium ions increase thermostability of both purified lipases I and II. The purified lipase I showed no metal ion dependence for its activity since EDTA up to 10 mM has no effect on the enzyme activity. However purified lipase II showed slight inhibition by EDTA at the same concentration. Moreover, a serine protease inhibitor, PMSF showed an inhibitory effect on both purified enzymes.
authors.affiliation: Institute for Graduate Studies and Research, Department of Bioscience and Technology University of Alexandria, Chatby 21526, Alexandria, Egypt. hesham25166@yahoo.com
authors.forename: Hesham M
authors.initials: HM
authors.lastname: Saeed
authors.forename: Taha I
authors.initials: TI
authors.lastname: Zaghloul
authors.forename: Ahmed I
authors.initials: AI
authors.lastname: Khalil
authors.forename: Mohamed T
authors.initials: MT
authors.lastname: Abdelbaeth
mesh_terms: D001483:Base Sequence; D002412:Cations / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology
chemical_list: D002412:Cations; D004269:DNA, Bacterial; D012967:Sodium Dodecyl Sulfate; D010664:Phenylmethylsulfonyl Fluoride; D004492:Edetic Acid; D008049:Lipase; D004121:Dimethyl Sulfoxide