title: Purification and characterization of a novel cholesterol esterase from Pseudomonas aeruginosa, with its application to cleaning lipid-stained contact lenses.
abstract: With the aim of developing a new cholesterol esterase for eliminating lipids on used contact lenses, microorganisms were screened for the enzyme activity. A Pseudomonas aeruginosa isolated from soil was found to produce a desirable enzyme. The enzyme had an isoelectric point of 3.2, and molecular mass of 58 kDa. The optimal temperature was around 53 degrees C at pH 7.0, and the optimal pH was from 5.5 to 9.5. The enzyme was stable between pH 5 and 10 for 19 h at 25 degrees C, and retained its activity up to 53 degrees C on 30 min of incubation at pH 7.0. The rates of hydrolysis of cholesteryl esters of different fatty acids were in the following order: linoleate > oleate > stearate > palmitate > caprylate > myristate > laurate, caprate > caproate > butyrate, acetate. Addition of (tauro)cholate to a final concentration of 100 mM markedly promoted the hydrolysis of triglycerides of short-, medium-, and long-chain fatty acids. When used with taurocholate, the enzyme acted as an effective cleaner for contact lenses stained with lipids consisting of cholesteryl oleate, tripalmitin, and stearyl stearate.
authors.affiliation: Osaka Municipal Technical Research Institute, 1-6-50 Morinomiya, Joto-ku, Osaka 536-8553, Japan. sugihara@omtri.city.osaka.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Sugihara
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shimada
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nomura
authors.forename: Tadamasa
authors.initials: T
authors.lastname: Terai
authors.forename: Masaki
authors.initials: M
authors.lastname: Imayasu
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nagai
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nagao
authors.forename: Yomi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tominaga
mesh_terms: D002788:Cholesterol Esters / Q000737:chemistry*; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003263:Contact Lenses, Hydrophilic; D003902:Detergents / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005227:Fatty Acids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007526:Isoelectric Point; D008049:Lipase / Q000737:chemistry / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D002787:Sterol Esterase / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry*; D014304:Triolein / Q000378:metabolism
chemical_list: D002788:Cholesterol Esters; D003902:Detergents; D005227:Fatty Acids; D014280:Triglycerides; D014304:Triolein; D002787:Sterol Esterase; D008049:Lipase