title: Steady-state fluorescence studies on lipase-vesicle interactions.
abstract: The interaction of lipase from Candida cylindracea (CCL) with positively charged polymerizable surfactant vesicles was studied by the use of steady-state fluorescence techniques. The phase transition of vesicles composed of nonpolymerized and polymerized N-allylbis[2-(hexadecanoyloxy)ethyl]methylammonium bromide (ABHEMA Br) was determined in the absence of lipase, by measuring the change in fluorescence anisotropy of the membrane probe 1,6-diphenyl-1,3,5-hexatriene (DPH). The phase transition temperature for nonpolymerized vesicles is 49 degrees C and for the polymerized analogues 45 degrees C. Fluorescence anisotropy and resonance energy transfer measurements were used to illustrate the incorporation of the lipase in the vesicle membrane. These studies demonstrated that CCL is incorporated into the hydrophobic bilayer of the vesicle. By using an interfacial membrane probe 1-[4-(trimethylammonium)phenyl]-6-phenyl-1,3,5-hexatriene p-toluene sulphonate, TMA-DPH) and an internal membrane probe (DPH), it could be determined that the enzyme is incorporated more efficiently into nonpolymerized vesicles, and that the penetration of the enzyme into the bilayer is less deep in the case of the polymerized vesicles.
authors.affiliation: Dept. of Organic Chemistry, Wageningen Agricultural University, The Netherlands.
authors.forename: E W
authors.initials: EW
authors.lastname: Mosmuller
authors.forename: E H
authors.initials: EH
authors.lastname: Pap
authors.forename: A J
authors.initials: AJ
authors.lastname: Visser
authors.forename: J F
authors.initials: JF
authors.lastname: Engbersen
mesh_terms: D000498:Allyl Compounds; D002175:Candida / Q000201:enzymology; D004161:Diphenylhexatriene; D004735:Energy Transfer; D005454:Fluorescence Polarization; D008049:Lipase / Q000378:metabolism*; D008051:Lipid Bilayers; D000644:Quaternary Ammonium Compounds
chemical_list: D000498:Allyl Compounds; D008051:Lipid Bilayers; D000644:Quaternary Ammonium Compounds; D004161:Diphenylhexatriene; C085774:N-allylbis(2-(hexadecanoyloxy)ethyl)methylammonium; D008049:Lipase