Multiplicity of acidic subunit isoforms of crotoxin, the phospholipase A2 neurotoxin from Crotalus durissus terrificus venom, results from posttranslational modifications.
AuthorsFaure G, Guillaume JL, Camoin L, Saliou B, Bon C
JournalBiochemistry
PubMed ID1868083
Crotoxin, the major toxin of the venom of the South American rattlesnake, Crotalus durissus terrificus, is made of two subunits: component B, a basic and weakly toxic phospholipase A2, and component A, an acidic and nontoxic protein that enhances the lethal potency of component B. Crotoxin is a mixture of ... More
Crotoxin, a phospholipase A2 neurotoxin from the South American rattlesnake Crotalus durissus terrificus: purification of several isoforms and comparison of their molecular structure and of their biological activities.
AuthorsFaure G, Bon C
JournalBiochemistry
PubMed ID3349062
'Crotoxin, the major toxin of the venom of the South American rattlesnake Crotalus durissus terrificus is a mixture of several isoforms that differ slightly in their molecular structure. The toxin consists of two nonidentical subunits: a basic and weakly toxic phospholipase A2, component B, and an acidic and nontoxic subunit, ... More
Continuous, vesicle-based fluorimetric assays of 14- and 85-kDa phospholipases A2.
AuthorsBayburt T, Yu BZ, Street I, Ghomashchi F, Laliberté F, Perrier H, Wang Z, Homan R, Jain MK, Gelb MH
JournalAnal Biochem
PubMed ID8600835
'This paper describes the synthesis and analysis of new substrates for the 85-kDa, mammalian, cytosolic phospholipase A2 (cPLA2) and the 14-kDa, human nonpancreatic, secreted phospholipase A2 (sPLA2). Phosphatidylcholines containing an arachidonyl chain at the sn-2 position and either a 10-pyrenedecyl or a 10-pyrenedecanoyl chain at the sn-1 position were synthesized ... More
Concomitant recruitment of ERK1/2 and p38 MAPK signalling pathway is required for activation of cytoplasmic phospholipase A2 via ATP in articular chondrocytes.
AuthorsBerenbaum F, Humbert L, Bereziat G, Thirion S
JournalJ Biol Chem
PubMed ID12591927
'Extracellular ATP is a pro-inflammatory mediator involved in the release of prostaglandin from articular chondrocytes, but little is known about its effects on intracellular signaling. ATP triggered the rapid release of prostaglandin E(2) (PGE(2)) by acting on P2Y(2) receptors in rabbit articular chondrocytes. We have explored the signaling events involved ... More
Phospholipid synthesis by extracellular phospholipase A2 in organic solvents.
AuthorsPernas P, Olivier JL, Legoy MD, Bereziat G
JournalBiochem Biophys Res Commun
PubMed ID2334428
'The catalytic activity of extracellular phospholipase A2 was studied in low polarity solvents where hydrolytic enzymes have been demonstrated to catalyze synthesis reactions. It was demonstrated that extracellular phospholipase A2 can catalyze the esterification of lysophosphatidylcholine with oleic acid. Up to 6.5% of lysophosphatidylcholine can be esterified into phosphatidylcholine. This ... More
Localization of structural elements of bee venom phospholipase A2 involved in N-type receptor binding and neurotoxicity.
AuthorsNicolas JP, Lin Y, Lambeau G, Ghomashchi F, Lazdunski M, Gelb MH
JournalJ Biol Chem
PubMed ID9054413
'We have shown previously that neurotoxic venom secretory phospholipases A2 (sPLA2s) have specific receptors in brain membranes called N-type receptors that are likely to play a role in the molecular events leading to neurotoxicity of these proteins. The sPLA2 found in honey bee venom is neurotoxic and binds to this ... More
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 sensitive and continuous fluorometric assay for phospholipase A2 using pyrene-labeled phospholipids in the presence of serum albumin.
AuthorsRadvanyi F, Jordan L, Russo-Marie F, Bon C
JournalAnal Biochem
PubMed ID2742139
Phospholipase A2 activity can be determined fluorometrically in the presence of serum albumin using phospholipids labeled at the sn-2-acyl position with 10-pyrenyldecanoic acid. In the water reaction medium 10-pyrene phospholipids form vesicles and the monomer fluorescence of the pyrene is negligible due to pyrene-pyrene interaction. Upon phospholipid hydrolysis 10-pyrenyldecanoic acids ... More
Novel human secreted phospholipase A(2) with homology to the group III bee venom enzyme.
AuthorsValentin E, Ghomashchi F, Gelb MH, Lazdunski M, Lambeau G
JournalJ Biol Chem
PubMed ID10713052
Venom and mammalian secreted phospholipases A(2) (sPLA(2)s) have been associated with numerous physiological, pathological, and toxic processes. So far, structurally related group I and II sPLA(2)s have been found in vertebrates such as mammals and snakes, whereas group III sPLA(2)s have mainly been found in venom from invertebrates such as ... More
High-generation polycationic dendrimers are unusually effective at disrupting anionic vesicles: membrane bending model.
AuthorsZhang ZY, Smith BD
JournalBioconjug Chem
PubMed ID11087328
The membrane disruption properties of high generation (G4 to G7) poly(amidoamine) (PAMAM) dendrimers are evaluated and compared to linear poly(lysine). The G6 and G7 dendrimers are unusually effective at inducing leaky fusion of anionic, large unilamellar vesicles, as determined by standard fluorescence assays for lipid mixing, leakage, and contents mixing. ... More
Binding of crotoxin, a presynaptic phospholipase A2 neurotoxin, to negatively charged phospholipid vesicles.
AuthorsRadvanyi F, Saliou B, Lembezat MP, Bon C
JournalJ Neurochem
PubMed ID2769265
Crotoxin, isolated from the venom of Crotalus durissus terrificus, is a potent neurotoxin consisting of a basic and weakly toxic phospholipase A2 subunit (component B) and an acidic nonenzymatic subunit (component A). The nontoxic component A enhances the toxicity of the phospholipase subunit by preventing its nonspecific adsorption. The binding ... More
Expression of the type-II phospholipase A2 in alveolar macrophages. Down-regulation by an inflammatory signal.
AuthorsVial D, Señorale-Pose M, Havet N, Molio L, Vargaftig BB, Touqui L
JournalJ Biol Chem
PubMed ID7615534
We have shown previously that guinea pig alveolar macrophages (AM) synthesize a secretory phospholipase A2 (PLA2) during in vitro incubation. Here, we report the molecular cloning of this enzyme and show that it has structural features closely related to all known mammalian type-II PLA2. The mRNA and PLA2 activity were ... More
Synergism between mellitin and phospholipase A2 from bee venom: apparent activation by intervesicle exchange of phospholipids.
AuthorsCajal Y, Jain MK
JournalBiochemistry
PubMed ID9092818
Mellitin, a cationic amphiphilic peptide, has an apparent activating effect on interfacial catalysis by phospholipase A2 (PLA2) of bee venom on zwitterionic vesicles of 1-palmitoyl-2-oleoylglycero-sn-3-phosphocholine (POPC) and on anionic vesicles of 1,2-dimyristoylglycero-sn-3-phosphomethanol (DMPM), as well as on covesicles of POPC/DMPM (3:7). On the other hand, mellitin-induced increase in the rate ... More
Phospholipase A2 engineering. Deletion of the C-terminus segment changes substrate specificity and uncouples calcium and substrate binding at the zwitterionic interface.
It has been suggested [Dijkstra, B. W., Drenth, J., & Kalk, K. H. (1981) Nature 289, 604-606] that the interfacial binding site of phospholipase A2 (PLA2) involves a large number of residues, including a cluster at the N-terminus and another cluster at the C-terminus. The approaches of multiple mutation and ... More