Inhibitory effects of gallic acid ester derivatives on Saccharomyces cerevisiae multidrug resistance protein Pdr5p.

Overexpression of the Saccharomyces cerevisiae ABC transporter Pdr5p confers resistance to a range of structurally unrelated xenobiotics. This property allows Pdr5p to be used as a target for novel multidrug resistance reversal reagents or chemosensitizers. Herein, we report the effects of gallic acid derivatives with substitutions either on the ester moiety or in the benzene ring on the activity of Pdr5p.

Hydroxychalcones induce apoptosis in B16-F10 melanoma cells via GSH and ATP depletion.

Searching for leading compounds of new drugs for cancer therapy, we studied the toxicity of 13 hydroxychalcones never tested before toward melanoma cell line (B16-F10). The compounds were obtained by aldolic condensation between aldehydes and hydroxylated acetophenones, in alkaline conditions. Three of them showed cytotoxicity to the cell line.

BE-I-PLA2, a novel acidic phospholipase A2 from Bothrops erythromelas venom: isolation, cloning and characterization as potent anti-platelet and inductor of prostaglandin I2 release by endothelial cells.

A novel acidic Asp49 phospholipase A(2) was isolated from Bothrops erythromelas (jararaca malha-de-cascavel) snake venom by four chromatographic steps. BE-I-PLA2 present a molecular weight of 13,649.57 Da as estimated by mass spectrometry.

Releasing or expression modulating mediator involved in hemostasis by Berythractivase and Jararhagin (SVMPs).

PIII snake venom metalloproteases (SVMPs) are structurally related to ADAMs (a disintegrin and metalloprotease human family of proteins). Berythractivase and Jararhagin are PIII SVMPs with 69% homology with different hemostatic properties. In order to clarify these differences and further characterize the biological effects of these proteins, we compared the effect of both proteases on human umbilical vein endothelial cell (HUVEC) for evaluating the release and modulation of coagulation and fibrinolysis mechanisms as well as the expression of their correlated genes.

Losac, a factor X activator from Lonomia obliqua bristle extract: its role in the pathophysiological mechanisms and cell survival.

Contact with the bristles of the caterpillar Lonomia obliqua can cause serious hemorrhage. Previously it was reported that a procoagulant protein (Lopap) in the bristle extract of L. obliqua increases cell longevity by inhibiting apoptosis.

Distribution of hexavalent Cr species across the clay mineral surface-water interface.

The adsorption isotherms of Cr(VI) on kaolinite, montmorillonite, and alumina were adequately treated with Langmuir model showing behavior characteristic of single-layer adsorption. The efficiency of the adsorbents in removing Cr(VI) from water follows the order alumina > kaolinite > montmorillonite > silica. Speciation studies indicate that hydrogen chromate ions were the major adsorbed species and simultaneous adsorption of dichromate ion occurred at concentrations greater than approximately 10(-3) mol L(-1).

Insularinase A, a prothrombin activator from Bothrops insularis venom, is a metalloprotease derived from a gene encoding protease and disintegrin domains.

The first low-molecular-mass metalloprotease presenting prothrombin activating activity was purified from Bothrops insularis venom and named insularinase A. It is a single-chain protease with a molecular mass of 22 639 Da. cDNA sequence analysis revealed that the disintegrin domain of the precursor protein is post-translationally processed, producing the mature insularinase A.

A prothrombin activator (Lopap) modulating inflammation, coagulation and cell survival mechanisms.

A severe hemorrhagic syndrome produced by contact with Lonomia obliqua caterpillars has become epidemic in southern Brazil. A significant thrombin production with intense consumption of fibrinogen and high D-dimer production indicates a consumption coagulopathy and secondary fibrinolysis in patients. Lopap is a single-chain 69kDa serine protease isolated from the crude extract of L.

The snake venom metalloproteases berythractivase and jararhagin activate endothelial cells.

PIII snake venom metalloproteases (SVMPs) are metalloproteases structurally related to ADAMs (a disintegrin and metalloprotease human family of proteins). Berythractivase and jararhagin are PIII SVMPs with 69% homology that have different hemostatic properties. In order to clarify these differences and further characterize the biological effects of these proteins, we have analyzed the effect of both proteases on human umbilical-vein endothelial cell functions.

Lonomia obliqua venom action on fibrinolytic system.

Accidental skin contact with the Lonomia caterpillar bristles causes a severe hemorrhagic syndrome. While fibrinolytic activation is considered to be the main cause of hemorrhage in Lonomia achelous envenomation, a consumptive coagulopathy was found to be a major component involved in the bleeding complications observed in patients envenomed by contact with Lonomia obliqua. Although we have previously observed that in L.

Effects of lopap on human endothelial cells and platelets.

Severe consumption coagulopathy has been detected in rats after Lopap (a prothrombin activator from Lonomia obliqua caterpillar bristles) infusion and in humans after accidental contact with L. obliqua bristles. However, platelet count and antithrombin (AT) levels were only modestly affected, suggesting that a different form of blood coagulation activation may be involved in this hemorrhagic syndrome.

A prothrombin activator serine protease from the Lonomia obliqua caterpillar venom (Lopap) biochemical characterization.

Lonomia obliqua venom causes a severe consumptive coagulopathy, which can lead to a hemorrhagic syndrome. The crude bristles extract displays a procoagulant activity due to a Factor X and to a prothrombin activating activity. Here, we describe a 69 kDa prothrombin activator serine protease purified from L.

Species- and subtype-specific recognition by antibody WF6 of a sequence segment forming an alpha-bungarotoxin binding site on the nicotinic acetylcholine receptor alpha subunit.

The monoclonal antibody WF6 competes with acetylcholine and alpha-bungarotoxin (alpha-BGT) for binding to the Torpedo nicotinic acetylcholine receptor (nAChR) alpha 1 subunit. Using synthetic peptides corresponding to the complete Torpedo nAChR alpha 1 subunit, we previously mapped a continuous epitope recognized by WF6, and the prototope for alpha-BGT, to the sequence segment alpha 1(181-200). Single amino acid substitution analogs have been used as an initial approach to determine the critical amino acids for WF6 and alpha-BGT binding.