The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The complete amino acid sequence of the 121 amino acid residues of piratoxin II, a phospholipase A 2 like myotoxin from Bothrops pirajai venom, is reported. PrTX-II is a basic protein with a molecular mass of 13740 Da, a calculated pI of 9.03, but an experimental pI of 8.4 ± 0.2, showing sequence similarity with other bothropic (90–99%) or non-bothropic (≈ 80%) Lys49 PLA 2 -like myotoxins...
Bothropstoxin-II (Bthtx-II), an Asp-49 phospholipase A 2 (D-PLA 2 ) isolated from Bothrops jararacussu snake venom is able to induce platelet aggregation in a concentration-dependent manner. This effect was not due to the release of ADP from platelets since the aggregation was not suppressed by ADP scavenger systems. PMSF and PPACK were unable to inhibit Bthtx-II-induced platelet aggregation...
The crystal structure of dimeric Lys49-phospholipase A2 myotoxin-II from Bothrops moojeni (MjTX-II) co-crystallized with stearic acid (C 18 H 36 O 2 ) has been determined at a resolution of 1.8 Å. The electron density maps permitted the unambiguous inclusion of six stearic acid molecules in the refinement. Two stearic acid molecules could be located in the substrate-binding...
Plasmalogens (Pls) are phospholipids containing a vinyl–ether bond at the sn-1 position of the glycerol backbone. They represent between 1/2 and 2/3 of the ethanolamine phospholipids in the brain. During aging, the Pls content in human brain falls down. However, the role of Pls metabolism-related enzymes in the regulation of Pls levels remains to be determined. Dihydroxyacetone phosphate acyltransferase...
A post-synaptic neurotoxic phospholipase A 2 (PLA 2 ) has been purified from Indian cobra Naja naja venom. It was associated with a peptide in the venom. The association was disrupted using 8 M urea. It is denoted to be a basic protein by its behavior on both ion exchange chromatography and electrophoresis. It is toxic to mice, LD 50 1.9 mg/kg body weight (ip). It is proved...
R180, isolated from porcine brain cortex, is a high-affinity membrane receptor for ammodytoxin A (AtxA), a secreted phospholipase A 2 (sPLA 2 ) and presynaptically active neurotoxin from venom of the long-nosed viper (Vipera ammodytes ammodytes). As a member of the M-type sPLA 2 receptors, present on the mammalian plasma membrane, R180 has been proposed to be responsible for...
Group IIA phospholipase A 2 (PLA 2 ) are major components in Viperidae/Crotalidae venom. In the present study, a novel PLA 2 named promutoxin with Arg at the site 49 has been purified from the venom of Protobothrops mucrosquamatus by chromatography. It consists of 122 amino acid residues with a molecular mass of 13,656 Da assessed by MALDI-TOF. It has the structural features...
Bothrops snake venoms contain a variety of phospholipases (PLA 2 ), some of which are myotoxic. In this work, we used reverse-phase HPLC and mass spectrometry to purify and sequence two PLA 2 from the venom of Bothrops insularis. The two enzymes, designated here as BinTX-I and BinTx-II, were acidic (pI 5.05 and 4.49) Asp49 PLA 2 , with molecular masses of 13,975 and 13,788,...
Bothropstoxin-I (BthTx-I) is a homodimeric Lys49-PLA 2 from the venom of the snake Bothrops jararacussu, which lacks hydrolytic activity against phospholipid substrates, yet permeabilizes membranes by a Ca 2+ -independent mechanism. The interaction of the BthTx-I with model membranes has been studied by intrinsic tryptophan fluorescence emission (ITFE) spectroscopy. Nine separate mutants...
Agkistrodon snake venoms contain a variety of phospholipases (PLA 2 ), some of which are myotoxic. In this study, we used reverse-phase HPLC to purify PLA 2 from the venom of Agkistrodon halys. The enzyme named as AgkTx-II, a basic Asp49 PLA 2 , has a molecular masses of 13,869.05. The amino acid sequence and molecular mass of AgkTx-II was identical to those of an Asp49 basic...
A phospholipase A 2 was isolated from the snake venom of Chinese Agkistrodon blomhoffii Ussurensis by column chromatography using DEAE Sephadex A-50 ion-exchange chromatography, Sephadex G-75 gel filtration chromatography and Mono Q ion-exchange chromatography, and designated as Akbu-PLA 2 . It showed an average molecular mass of 13,980±3amu determined by MALDI TOF mass spectrometry...
Crotoxin (CA.CB) is a β-neurotoxin from Crotalus durissus terrificus snake venom that is responsible for main envenomation effects upon biting by this snake. It is a heterodimer of an acidic protein (CA) devoid of any biological activity per se and a basic, enzymatically active, PLA 2 counterpart (CB). Both lethal and enzymatic activities of crotoxin have been shown to be inhibited by CNF,...
Phospholipases A 2 (PLA 2 ) are major components of snake venoms, exerting a variety of relevant toxic actions such as neurotoxicity and myotoxicity, among others. Since the majority of toxic PLA 2 s are basic proteins, acidic isoforms and their possible roles in venoms are less understood. In this study, an acidic enzyme (BaspPLA 2 -II) was isolated from the venom...
Peroxiredoxins (Prx) are enzymes that catalyze the reduction of hydrogen peroxide and alkyl hydroperoxides. Prxs are ubiquitous enzymes with representatives found in Bacteria, Archaea and Eukarya. Many 1-cysteine peroxiredoxins (1-CysPrx) are dual-function enzyme with both peroxidase and acidic Ca 2+ -independent phospholipase A 2 (aiPLA 2 ) activities. The functions proposed...
Among the emerging phospholipase A 2 (PLA 2 ) superfamily, the secreted PLA 2 (sPLA 2 ) family consists of low-molecular-mass, Ca 2+ -requiring extracellular enzymes with a His-Asp catalytic dyad. To date, more than 10 sPLA 2 enzymes have been identified in mammals. Individual sPLA 2 s exhibit unique tissue and cellular localizations and enzymatic...
The distribution of fatty acids among cellular glycerophospholipids is finely regulated by the CoA-dependent acylation of lysophospholipids followed by transacylation reactions. Arachidonic acid is the fatty acid precursor of a wide family of bioactive compounds called the eicosanoids, with key roles in innate immunity and inflammation. Because availability of free AA constitutes a rate-limiting step...
Type-IIA secreted phospholipase A 2 (sPLA 2 -IIA) has been proposed to play a role in the development of inflammatory diseases. It has been shown to release arachidonic acid, the precursor of proinflammatory eicosanoids, to hydrolyze phospholipids of pulmonary surfactant, and to bind to specific receptors located on cell surface membranes. However, the most established biological role...
Leukotrienes are a family of proinflammatory lipid mediators of the innate immune response and are important signaling molecules in inflammatory and allergic conditions. The leukotrienes are formed from arachidonic acid, which is released from membranes by cPLA 2 , and further converted by 5-lipoxygenase to form the labile epoxide leukotriene (LT) A 4 . This intermediate is converted...
Phospholipase A 2 (PLA 2 ) enzymes (EC3.1.4.4) regulate the release of biologically active fatty acids and lysophospholipids from membrane phospholipid pools. These lipids are also substrates for intracellular biochemical pathways that generate potent autocrine and paracrine lipid mediators such as the eicosanoids and platelet activating factor. These factors, in turn, regulate cell...
This work aimed at the isolation and structural/functional characterization of a phospholipase A 2 (CgPLA 2 ) from the extract of the anemone Condylactis gigantea. CgPLA 2 was isolated with a high purity level through three chromatographic steps, showing pI˜8.6 and molecular weights of 14,500 and 29,000 for the monomer and dimer, respectively. CgPLA 2 showed a high...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.