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Article: Lipid vesicle fusion induced by phospholipase C activity in model bile

TitleLipid vesicle fusion induced by phospholipase C activity in model bile
Authors
Issue Date1993
PublisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jlr.org/
Citation
Journal Of Lipid Research, 1993, v. 34 n. 2, p. 211-217 How to Cite?
AbstractUsing a system of phosphatidylcholine-cholesterol vesicles to model the vesicle phase of mammalian bile (1:1 molar ratio) we evaluated whether very small amounts of C. perfringens phospholipase C activity (0.5-6.5 nmol/min per ml) could lead to vesicle fusion, a precursor step for cholesterol precipitation in gallbladder bile. Quasielastic light scattering spectroscopy (QLS) was used to monitor vesicle growth and aggregation in model bile (0.89 mM total lipid) in the presence of phospholipase C. Vesicle growth over 2 h could be detected with phospholipase activity as little as 0.5 nmol/min per ml. Vesicle growth was sustainable over days in the absence of Ca2+ once as little as 3-7 mol% diacylglycerol had been generated as a result of the initial phospholipase C treatment. The presence of fusion intermediates was confirmed using transmission electron microscopy. In addition, kinetically slow vesicle fusion with intravesicle content mixing and minimal leakage was also confirmed by fluorescence spectroscopy using two populations of vesicles containing 5 mM TbCl3 or 50 mM dipicolinic acid. Efficient fusion (40% maximum fluorescence) was obtained at 30 min at 25°C with phospholipase C activity. This level of enzyme activity approximates that found in human gallbladder bile (1.2 nmol/min per ml). We conclude that the hydrolysis products of phospholipase C activity can, in very small amounts (3-7 mol% diacylglycerol), lead to destabilization and fusion of cholesterol-saturated biliary vesicles. A reappraisal of the importance of phospholipase C hydrolysis products in the pathogenesis of cholesterol gallstones is warranted based on these observations.
Persistent Identifierhttp://hdl.handle.net/10722/175684
ISSN
2015 Impact Factor: 4.368
2015 SCImago Journal Rankings: 2.529
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorLittle, TEen_US
dc.contributor.authorMadani, Hen_US
dc.contributor.authorLee, SPen_US
dc.contributor.authorKaler, EWen_US
dc.date.accessioned2012-11-26T09:00:29Z-
dc.date.available2012-11-26T09:00:29Z-
dc.date.issued1993en_US
dc.identifier.citationJournal Of Lipid Research, 1993, v. 34 n. 2, p. 211-217en_US
dc.identifier.issn0022-2275en_US
dc.identifier.urihttp://hdl.handle.net/10722/175684-
dc.description.abstractUsing a system of phosphatidylcholine-cholesterol vesicles to model the vesicle phase of mammalian bile (1:1 molar ratio) we evaluated whether very small amounts of C. perfringens phospholipase C activity (0.5-6.5 nmol/min per ml) could lead to vesicle fusion, a precursor step for cholesterol precipitation in gallbladder bile. Quasielastic light scattering spectroscopy (QLS) was used to monitor vesicle growth and aggregation in model bile (0.89 mM total lipid) in the presence of phospholipase C. Vesicle growth over 2 h could be detected with phospholipase activity as little as 0.5 nmol/min per ml. Vesicle growth was sustainable over days in the absence of Ca2+ once as little as 3-7 mol% diacylglycerol had been generated as a result of the initial phospholipase C treatment. The presence of fusion intermediates was confirmed using transmission electron microscopy. In addition, kinetically slow vesicle fusion with intravesicle content mixing and minimal leakage was also confirmed by fluorescence spectroscopy using two populations of vesicles containing 5 mM TbCl3 or 50 mM dipicolinic acid. Efficient fusion (40% maximum fluorescence) was obtained at 30 min at 25°C with phospholipase C activity. This level of enzyme activity approximates that found in human gallbladder bile (1.2 nmol/min per ml). We conclude that the hydrolysis products of phospholipase C activity can, in very small amounts (3-7 mol% diacylglycerol), lead to destabilization and fusion of cholesterol-saturated biliary vesicles. A reappraisal of the importance of phospholipase C hydrolysis products in the pathogenesis of cholesterol gallstones is warranted based on these observations.en_US
dc.languageengen_US
dc.publisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jlr.org/en_US
dc.relation.ispartofJournal of Lipid Researchen_US
dc.subject.meshBile - Chemistryen_US
dc.subject.meshCalcium - Pharmacologyen_US
dc.subject.meshClostridium Perfringens - Enzymologyen_US
dc.subject.meshCrystallizationen_US
dc.subject.meshEdetic Acid - Pharmacologyen_US
dc.subject.meshLighten_US
dc.subject.meshLipid Metabolismen_US
dc.subject.meshLiposomes - Metabolismen_US
dc.subject.meshMembrane Fusionen_US
dc.subject.meshMicroscopy, Electronen_US
dc.subject.meshParticle Sizeen_US
dc.subject.meshPhosphatidylcholines - Metabolismen_US
dc.subject.meshScattering, Radiationen_US
dc.subject.meshSpectrometry, Fluorescenceen_US
dc.subject.meshSpectrum Analysisen_US
dc.subject.meshType C Phospholipases - Metabolismen_US
dc.titleLipid vesicle fusion induced by phospholipase C activity in model bileen_US
dc.typeArticleen_US
dc.identifier.emailLee, SP: sumlee@hku.hken_US
dc.identifier.authorityLee, SP=rp01351en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.pmid8429256-
dc.identifier.scopuseid_2-s2.0-0027407050en_US
dc.identifier.volume34en_US
dc.identifier.issue2en_US
dc.identifier.spage211en_US
dc.identifier.epage217en_US
dc.identifier.isiWOS:A1993KL95900005-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLittle, TE=35822432000en_US
dc.identifier.scopusauthoridMadani, H=6701613342en_US
dc.identifier.scopusauthoridLee, SP=7601417497en_US
dc.identifier.scopusauthoridKaler, EW=7007157989en_US

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