Fibrinogen-clotting enzyme, pictobin, from Bothrops pictus snake venom. Structural and functional characterization.

A thrombin-like enzyme, pictobin, was purified from Bothrops pictus snake venom. It is a 41-kDa monomeric glycoprotein as showed by mass spectrometry and contains approx. 45% carbohydrate by mass which could be removed with N-glycosidase.

Thrombin generation test for evaluating hemostatic effects of Brazilian snake venoms.

Snake venoms as well as their components have been tested worldwide to find new molecules for prophylaxis and treatment of several pathologies or even for diagnostic purposes. It is widely known that snake venoms contain enzymes and non-enzymatic proteins that interfere with hemostasis leading to hemorrhage or even thrombosis. The treatment of snake envenoming and the development of new drugs.

Effectiveness to identify acute myocardial infarction using the Manchester screening in patients with chest pain at the emergency service.

Background: Among cardiovascular diseases (CVD), acute coronary syndrome (ACS) is the main manifestation, corresponding to signs and symptoms that occur with ischemia and outcome of angina or acute myocardial infarction (AMI). The aim of this study was to investigate the performance of biochemical markers eligible in a chest pain protocol, using Point of care Test (POCT), in patients in a reference emergency room.

Methods: In this study, 1380 medical records of patients of both genders were evaluated, ranked by applying chest pain protocol using the Manchester Triage System (MTS).

Mechanism of action and determination of the best substrate for a thrombin-like enzyme from Lachesis muta muta venom by regression analysis of the kinetic parameters determined with peptidyl p-nitroanilide substrates.

The kinetic behavior of a thrombin-like enzyme from Lachesis muta muta venom has been studied with 13 tripeptidyl p-nitroanilide substrates. Eight substrates were unprotected at the N terminus and were used for the regression analysis of the experimentally determined kinetic parameters 1/Km, kcat and kcat/Km. The individual contribution of each amino acid side chain to the kinetic parameters was calculated.

Purification and properties of a coagulant thrombin-like enzyme from the venom of Bothrops leucurus.

A thrombin-like enzyme from Bothrops leucurus venom, named leucurobin (leuc), was purified by gel filtration, affinity and ion exchange chromatographies. Physicochemical studies indicated that the purified enzyme is a 35 kDa monomeric glycoprotein on SDS-PAGE under reducing conditions, which decreased to 29 kDa after deglycosylation with N-glycosidase F (PNGase F). The amino acid sequence of leuc was determined by automated sequencing of the intact native protein and peptides produced by digestion of the S-pyridyl-ethylated protein with trypsin.

Biochemical properties of a bushmaster snake venom serine proteinase (LV-Ka), and its kinin releasing activity evaluated in rat mesenteric arterial rings.

A serine proteinase with kallikrein-like activity (LV-Ka) has been purified to homogeneity from bushmaster snake (Lachesis muta muta) venom. Physicochemical studies indicated that LV-Ka is a single chain glycoprotein with a molecular mass (Mr) of 33 kDa under reducing conditions which was reduced to 28 kDa after treatment with N-Glycosidase F (PNGase F). LV-Ka can be bounded and neutralized by serum alpha2-macroglobulin (alpha2-M), a prevalent mammalian protease inhibitor that is capable of forming a macromolecular complex with LV-Ka (Mr >180 kDa).

Coagulant thrombin-like enzymes from the venoms of Brazilian and Peruvian bushmaster (Lachesis muta muta) snakes.

Two isoforms of a thrombin-like enzyme designated TLE-B and TLE-P were purified from the venoms of Lachesis muta muta (bushmaster) snakes captured in two different geographical localities, Manaus (Brazil) and Pucallpa (Perú). TLE-B and TLE-P showed Mr values of 44000 and 43000 under reducing conditions on SDS-PAGE, which decreased to 27000 after deglycosylation with N-glycosidase F (PNGase F). The purified proteinases split off fibrinopeptide A rapidly from human fibrinogen and fibrinopeptide B more slowly.