title: Inhibition or activation of Pseudomonas species lipase by 1,2-ethylene-di-N-alkylcarbamates in detergents.
abstract: 1,2-Ethylene-di-N-n-propylcarbamate (1) is characterized as an essential activator of Pseudomonas species lipase while 1,2-ethylene-di-N-n-butyl-, t-butyl-, n-heptyl-, and n-octyl-carbamates (2-5) are characterized as the pseudo substrate inhibitors of the enzyme in the presence of the detergent taurocholate or triton X-100. The inhibition and activation reactions are more sensitive in taurocholate than in triton X-100. From CD studies, the enzyme changes conformations in the presence of the detergent and further alters conformations by addition of the carbamate activator or inhibitor into the enzyme-detergent adduct. Therefore, this study suggests that the conformational change of lipase during interfacial activation is a continuous process to expose the active site of the enzyme to substrate. From 600 MHz (1)H NMR studies, the conformations of the alpha- and beta-methylene moieties of the activator 1,2-ethylene-di-N-n-propylcarbamate in the presence of substrate change after adding taurocholate into the mixture, and the conformations of the beta-methylene moieties of the inhibitor 1,2-ethylene-di-N-n-butylcarbamate in the presence of substrate alter after adding taurocholate into the mixture.
authors.affiliation: Institute of Medicine, Department of Cardiology, Chung Shan Medical University Hospital, Taichung 402, Taiwan.
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Lin
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Lu
authors.forename: Yu-Ru
authors.initials: YR
authors.lastname: Cheng
authors.forename: Yan-Fu
authors.initials: YF
authors.lastname: Lin
authors.forename: Chung-Sheng
authors.initials: CS
authors.lastname: Lin
authors.forename: Gialih
authors.initials: G
authors.lastname: Lin
mesh_terms: D002219:Carbamates / Q000494:pharmacology*; D003902:Detergents / Q000737:chemistry*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008049:Lipase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011549:Pseudomonas / Q000201:enzymology*
chemical_list: D002219:Carbamates; D003902:Detergents; D004791:Enzyme Inhibitors; D008049:Lipase