Detection and characterization of the onset of bilayer packing defects by nanosecond-resolved intramolecular excimer fluorescence spectroscopy.
AuthorsCheng KH, Somerharju P, Sugar I
JournalChem Phys Lipids
PubMed ID7820901
'Bilayer packing defects in binary dilinoleoylphosphatidylethanolamine and 1-palmitoyl-2-oleoylphosphatidylcholine (DLPE/POPC) lipid mixtures have been studied by the use of nanosecond-resolved intramolecular excimer fluorescence spectroscopy. Frequency-domain fluorescence intensity decays of dual-chain labelled dipyrenyl lipids of different chain lengths in DLPE/POPC mixtures were acquired at both the monomer (392 nm) and excimer (475 ... More
Intramolecular excimer kinetics of fluorescent dipyrenyl lipids: 1. DMPC/cholesterol membranes.
AuthorsCheng KH, Ruymgaart L, Liu LI, Somerharju P, Sugar IP
JournalBiophys J
PubMed ID7948704
'The intramolecular dynamics of the excimer forming dipyrenyl lipids (DipynPC) of different chain lengths (n) in ethanol and in dimyristoylphosphatidycholine (DMPC) membranes was investigated by the use of frequency-domain fluorescence intensity decay technique. Based on a 3-state model, the extent of aggregation and rotational rate of the two intralipid pyrene ... More
Oxidation of unsaturated phospholipids in membrane bilayer mixtures is accompanied by membrane fluidity changes.
AuthorsBorst JW, Visser NV, Kouptsova O, Visser AJ
JournalBiochim Biophys Acta
PubMed ID10962288
'Steady-state and time-resolved fluorescence spectroscopy has been used to obtain information on oxidation processes and associated dynamical and structural changes in model membrane bilayers made from single unilamellar vesicles (SUV''s) of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) mixed with increasing amounts of 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (SAPC). The highly unsaturated arachidonoyl chain containing four double bonds is ... More
Headgroup specificity of lecithin cholesterol acyltransferase for monomeric and vesicular phospholipids.
AuthorsChristiaens B, Vanloo B, Gouyette C, Van Vynckt I, Caster H, Taveirne J, Verhee A, Labeur C, Peelman F, Vandekerckhove J, Tavernier J, Rosseneu M
JournalBiochim Biophys Acta
PubMed ID10903483
'In this study, we investigated how the nature of the phospholipid head group and the macromolecular structure of the phospholipid, either as a monomer or incorporated into a lipid matrix, influence the activity of lecithin cholesterol acyltransferase (LCAT). As substrates we used 1,2-bis-(1-pyrenebutanoyl)-phosphatidylcholine, 1, 2-bis-(1-pyrenebutanoyl)-phosphatidylethanolamine and 1, 2-bis-(1-pyrenebutanoyl)-phosphatidyl-alcohols, either as ... More
Continuous fluorometric assay of phospholipase A2 with pyrene-labeled lecithin as a substrate.
AuthorsHendrickson HS, Rauk PN
JournalAnal Biochem
PubMed ID7316183
Pyrene-labeled lipids as tools in membrane biophysics and cell biology.
AuthorsSomerharju P
JournalChem Phys Lipids
PubMed ID12093535
Pyrene is one of the most frequently used lipid-linked fluorophores. Its most characteristic features are a long excited state lifetime and (local) concentration-dependent formation of excimers. Pyrene is also hydrophobic and thus does not significantly distort the conformation of the labeled lipid molecule. These characteristics make pyrene lipids well-suited for ... More
A model for the molecular mechanism of interfacial activation of phospholipase A2 supporting the substrate theory.
AuthorsThuren T
JournalFEBS Lett
PubMed ID3345843
Changes occurring in the activity of porcine pancreatic phospholipase A2 upon formation of mixed micelles of sodium cholate and the fluorescent phosphocholines 1,2-di[6-(pyren-1-yl)butanoyl]-sn-glycero-3-phosphocholine or 1-[6-(pyren-1-yl)butanoyl]-2-[6-(pyren-1-yl)hexanoyl]- sn-glycero-3- phosphocholine were studied. A 2-fold enhancement was observed in the activity of phospholipase A2 towards both pyrene phospholipids upon exceeding the critical micellar concentration ... More
Continuous fluorescence assay for lecithin:cholesterol acyltransferase using a water-soluble phosphatidylcholine.
AuthorsBonelli FS, Jonas A
JournalJ Lipid Res
PubMed ID1479295
A water-soluble fluorescent phosphatidylcholine, 1,2-bis[4-(1-pyreno-butanoyl]-sn-glycero-3-phosphocholine (DPybPC) has been used to develop a sensitive, continuous assay for pure lecithin:cholesterol acyltransferase (LCAT) in solution. The monomeric substrate allowed us to examine the reaction of LCAT in the absence of a lipid/water interface in terms of the sensitivity of the enzymatic reaction to ... More
Intramolecular excimer kinetics of fluorescent dipyrenyl lipids: 2. DOPE/DOPC membranes.
AuthorsCheng KH, Ruymgaart L, Liu LI, Somerharju P, Sugar IP
JournalBiophys J
PubMed ID7948705
The intramolecular dynamics of the excimer-forming dipyrenyl lipids (DipynPE) of different chain lengths (n) in fully hydrated dioleoylphosphatidylethanolamine (DOPE) and dioleoylphosphatidylcholine (DOPC) binary mixtures was investigated by the use of frequency-domain fluorescence intensity dcay technique. Using a 3-state model (see companion paper), the extent of aggregation and rotational rate of ... More
Fluorescence studies of lipid regular distribution in membranes.
AuthorsChong PL, Sugár IP
JournalChem Phys Lipids
PubMed ID12093540
This article reviews the use of fluorescent lipids and free probes in the studies of lipid regular distribution in model membranes. The first part of this article summarizes the evidence and physical properties for lipid regular distribution in pyrene-labeled phosphatidylcholine (PC)/unlabeled PC binary mixtures as revealed by the fluorescence of ... More
Fluorescence imaging of pyrene-labeled lipids in living cells.
AuthorsTanhuanpää K, Virtanen J, Somerharju P
JournalBiochim Biophys Acta
PubMed ID10996655
Microscopic imaging of fluorescent lipid derivatives is a powerful tool to study membrane organization and lipid trafficking but it is complicated by cellular autofluorescence background and photobleaching of the fluorophore as well as by the difficulty to selectively image membranes stacked on top of each other. Here we describe protocols ... More
Metabolism and distribution of intramolecular excimer-forming dipyrenebutanoyl glycerophospholipids in human fibroblasts. Marked resistance to metabolic degradation.
AuthorsKasurinen J, Somerharju P
JournalBiochemistry
PubMed ID7849063
Metabolism and intracellular distribution of fluorescent 1, 2-dipyrenebutanoyl derivatives of phosphatidylcholine, -ethanolamine, and -serine and phosphatidic acid (diPyr4PC, -PE, -PS, and -PA, respectively) in human skin fibroblasts (HF) has been studied. When HF cells were co-incubated with phospholipid vesicles containing diPyr4PC at 8 degrees C, considerable amounts of fluorescent lipid ... More