Isolation and characterization of moojenin, an acid-active, anticoagulant metalloproteinase from Bothrops moojeni venom

Abstract

A fibrinogenolytic metalloproteinase from Bothrops moojeni venom, named moojenin, was purified by a combination of ion-exchange chromatography on DEAE-Sephacel and gel filtration on Sephacryl S-300. SDS-PAGE analysis indicated that moojenin consists of a single polypeptide chain and has a molecular mass about 45 kDa. Sequencing of moojenin by Edman degradation revealed the amino acid sequence LGPDIVSPPVCGNELLEVGEECDCGTPENCQNE, which showed strong identity with many other snake venom metalloproteinases (SVMPs). The enzyme cleaves the Aα-chain of fibrinogen first, followed by the Bβ-chain, and shows no effects on the γ-chain. Moojenin showed a coagulant activity on bovine plasma about 3.1 fold lower than crude venom. The fibrinogenolytic and coagulant activities of the moojenin were abolished by preincubation with EDTA, 1,10-phenanthroline and β-mercaptoethanol. Moojenin showed maximum activity at temperatures ranging from 30 to 40 °C and its optimal pH was 4.0. Its activity was completely lost at temperatures above 50 °C. Moojenin induced necrosis in liver and muscle, evidenced by morphological alterations, but did not cause histological alterations in mouse lungs, kidney or heart. Moojenin rendered the blood uncoagulatable when it was intraperitoneally administered into mice. This metalloproteinase may be of medical interest because of its anticoagulant activity.

Clotting and fibrinogenolysis inhibition by essential oils from species of the Asteraceae family

“…Venoms generally produce local effects such as hemorrhage, necrosis, edema and intense pain, and systemic effects such as bleeding disorders, cardiovascular shock and acute renal failure 1 . Snake venoms present different actions that depend on the specific combinations of their components, such as phospholipases A2, serineproteases, metalloproteinases, hyaluronidases and L-amino acid oxidases 2 .…”

Bothrops jararaca envenomation: Pathogenesis of hemostatic disturbances and intravascular hemolysis

“…5 Particularly, venoms from Bothrops snakes (family Viperidae), which account for around 20,000 snakebites in Brazil annually, 6 contain several toxins that interfere in blood coagulation: (a) procoagulant enzymes that directly activate prothrombin [7][8][9][10][11][12][13][14][15] or factor X 8,16,17 zymogens, eventually generating meizothrombin or a-thrombin (prothrombin and factor X activators, respectively); (b) thrombin-like enzymes, i.e. toxins that cleave fibrinopeptides from fibrinogen, converting it into fibrin; 18 (c) fibrinogenolytic enzymes, which hydrolyze fibrinogen Aa and Bb chains, but do not convert fibrinogen into fibrin; [19][20][21][22] (d) protein C activators, which activate protein C; 23 and (e) C-type lectin-like proteins that inhibit the biological activities of thrombin 24,25 or factors IX/X. 26 Despite this plethora of toxins that disturb blood coagulation, it is an open question which of these toxins is the most important for promoting the hemostatic disturbances characteristic of human envenomation.…”

Preliminary assessment of Hedychium coronarium essential oil on fibrinogenolytic and coagulant activity induced by Bothrops and Lachesis snake venoms

“…Snake venoms are composed mainly of proteins with enzymatic activity that belong to different classes, such as L-amino acid oxidases, phospholipases A 2 , serine proteases and metalloproteases, the two latter being primarily responsible for effects on hemostasis [ 11 ]. The combination of these protein compounds is directly related to the damage caused by these venoms, whose pathophysiology includes local effects (intense pain, edema, hemorrhage and necrosis) and/or systemic effects, such as nausea, coagulopathy, hypotension, cardiovascular shock and kidney disorders [ 12 ].…”