title: LmrTX, a basic PLA₂ (D49) purified from Lachesis muta rhombeata snake venom with enzymatic-related antithrombotic and anticoagulant activity.
abstract: A basic phospholipase A₂ (LmrTX) isoform was isolated from Lachesis muta rhombeata snake venom and partially characterized. The venom was fractionated by molecular exclusion chromatography in ammonium bicarbonate buffer followed by reverse-phase HPLC on a C-5 Discovery® Bio Wide column. From liquid chromatography-electrospray ionization/mass spectrometry, the molecular mass of LmrTX was measured as 14.277.50 Da. The amino acid sequence showed a high degree of homology between PLA₂ LmrTX from L. muta rhombeata and other PLA₂ from snake venoms, like CB1 and CB2 from Crotalus durissus terrificus; LmTX-I and LmTX-II from Lachesis muta muta. LmrTX had PLA₂ activity in the presence of a synthetic substrate and alkylation of histidine residues significantly inhibited (P < 0.05) the enzymatic activity of LmrTX and its anticoagulant and antithrombotic activity. In this study, we examined the ability of the LmrTX in altering thrombus formation in living mouse, using a photochemically induced arterial thrombosis model. The control animals that did not receive protein injection showed a normal occlusion time, which was around 57 ± 7.8 min. LmrTX, the PLA₂ from L. muta rhombeata venom, caused a change in the occlusion time to 99 ± 10 min with doses of 7.5 μg/mice. Additionally, LmrTX showed the anticoagulant activity in vitro and ex vivo and prolonging the time aggregation in wash platelet induced by ADP and Thrombin.
authors: Department of Biochemistry, Institute of Biology, University of Campinas-UNICAMP, PO Box 6109, CEP 13083-970, Campinas, SP, Brazil. dcdamico@terra.com.br
authors: Daniela C S
authors: DC
authors: Damico
authors: T
authors: T
authors: Vassequi-Silva
authors: F D
authors: FD
authors: Torres-Huaco
authors: A C C
authors: AC
authors: Nery-Diez
authors: R C G
authors: RC
authors: de Souza
authors: S L
authors: SL
authors: Da Silva
authors: C P
authors: CP
authors: Vicente
authors: C B
authors: CB
authors: Mendes
authors: E
authors: E
authors: Antunes
authors: C C
authors: CC
authors: Werneck
authors: Sérgio
authors: S
authors: Marangoni
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D003435:Crotalid Venoms / Q000201:enzymology*; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D054467:Phospholipases A2 / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013927:Thrombosis / Q000139:chemically induced*
chemical_list: D003435:Crotalid Venoms; C072644:Lachesis venom; D054467:Phospholipases A2