A novel phospholipase A2, BJ-PLA2, from the venom of the snake Bothrops jararaca: purification, primary structure analysis, and its characterization as a platelet-aggregation-inhibiting factor.

This paper describes the isolation and primary structure analysis of a new phospholipase A2 with platelet-aggregation-inhibiting activity from the venom of Bothrops jararaca. The protein, named BJ-PLA2, was isolated by means of ammonium sulfate precipitation and anion-exchange and reversed-phase chromatographies and behaved as a homogeneous single-chain protein on SDS-PAGE. Its amino acid sequence was determined by N-terminal sequencing and analysis of overlapped chemical and proteolytic fragments by automated Edman degradation and mass spectometry determination. BJ-PLA2 consists of 124 amino acid residues and has the structural features of snake venom class II phospholipases A2. Chemical modification with p-bromophenacylbromide caused complete loss of enzymatic activity and partially affected the platelet-aggregation-inhibiting activity of BJ-PLA2.

Characterization of a myotoxin from the Duvernoy's gland secretion of the xenodontine colubrid Philodryas olfersii (green snake): effects on striated muscle and the neuromuscular junction.

A myotoxin has been isolated from the Duvernoy's gland (DG) secretion of the xenodontine colubrid Philodrvas olfersii (green snake) by gel filtration on Sephadex G-100 SF. Under non-reducing and reducing conditions in SDS-PAGE, the myotoxin migrates as a single band with a mol. wt. of 20000. The toxin has 182 amino acid residues (approximately 20% acidic), a pI of 4.8 and a blocked N-terminal. In the chick biventer cervicis preparation, P. olfersii myotoxin partially blocks potassium-evoked contractures without affecting either the twitch-tension resulting from indirect stimulation or the contractures evoked by acetylcholine. Both the DG secretion and the myotoxin increase the serum creatine kinase (CK) levels of mice and stimulate the release of CK from the biventer cervicis preparation in a dose- and time-dependent manner. The varying degrees of muscle cell lysis and extensive widening of the intercellular spaces caused by the DG secretion are reproduced by the myotoxin, with the exception that in the latter the partial or total loss of transverse muscle striations is restricted to the muscle periphery. This myotoxin is the first such protein to be characterized from a DG secretion.

Isolation, characterization and biological properties of two kinin-like peptides (peptide-S and peptide-r) from Scaptocosa raptoria venom.

Two peptides with kinin-like biological properties were isolated by chromatography on a Sephadex G-10 column followed by high-performance liquid chromatography, from the venom of the spider Scaptocosa raptoria. The isolated peptides (peptide-S and peptide-R) were shown to cause contraction on the isolated guinea-pig ileum at amounts equivalent to those shown by bradykinin. Both peptides relaxed the isolated rat duodenum, increased the capillary permeability, caused decreasing and biphasic effect of the arterial blood pressure in conscious rats and induced oedema in the rat paw. The peptides had activity and structural similarities to other peptides (kinin-like) isolated from venoms. The complete amino acid analysis gave peptide-S a structure with 36 amino acid residues and peptide-R 22 amino acid residues. The mol. wts were estimated to be in the range of 4000 and 2870, respectively.

Plasma arginine-vasotocin and hydroosmotic status of the terrestrial pit viper Bothrops jararaca.

Peaks corresponding to arg-vasotocin obtained by HPLC from Sep-Pak C18 column extracts of Bothrops jararaca plasma were identified by radioimmunoassay and amino acid analysis. Plasma vasotocin and protein levels, osmolality, and L-cystine-di-beta-naphthylamidase were also compared in snakes under normal hydration conditions with or without chronic administration of vasotocin or in the presence of chronic hydroosmotic challenges. Sep-Pak C18 and radioimmunoassay were validated for the extraction and determination of this peptide, respectively (about 80% recovery). EDTA presented a protective action on this recovery compared to the use of heparin as anticoagulant for snake blood. A reduction of vasotocin content related to the time of incubation of this peptide added to snake plasma was detected by radioimmunoassay. Snake plasma activity also on L-cystine-di-beta-naphthylamide indicated that this vasotocin-destroying effect was due to hydrolysis by a cystine-aminopeptidase-like activity. Plasma levels of vasotocin revealed an unexpected dispersion and absent correlation with plasma levels of osmolality. Measurable vasotocin in a large number of snakes associated with lower levels of l-cystine-di-beta-naphthylamidase in acute than in chronic salt loading suggested the role of this enzyme activity in long-term regulation of the vasotocin system in this snake.

Structural features that make oligopeptides susceptible substrates for hydrolysis by recombinant thimet oligopeptidase.

A systematic analysis of the peptide sequences and lengths of several homologues of bioactive peptides and of a number of quenched-fluorescence (qf) opioid- and bradykinin-related peptides was performed to determine the main features leading the oligopeptides to hydrolysis by the recombinant rat testis thimet oligopeptidase (EC 3.4.24.15). The results indicate that a minimum substrate length of six amino acids is required and that among the oligopeptides six to thirteen amino acid residues long, their susceptibility as substrates is highly variable. Thimet oligopeptidase was able to hydrolyse, with similar catalytic efficiency, peptide bonds having hydrophobic or hydrophilic amino acids as well as proline in the P1 position of peptides, ranging from a minimum of six to a maximum of approximately thirteen amino acid residues. An intriguing observation was the shift of the cleavage site, at a Leu-Arg bond in qf dynorphin-(2-8) [qf-Dyn2-8; Abz-GGFLRRV-EDDnp, where Abz stands for o-aminobenzoyl and EDDnp for N-(2,4-dinitrophenyl)ethylenediamine], to Arg-Arg in qf-Dyn2-8Q, in which Gln was substituted for Val at its C-terminus. Similarly, a cleavage site displacement was also observed with the hydrolysis of the internally quenched-fluorescence bradykinin analogues containing Gln at the C-terminal position, namely Abz-RPPGFSPFR-EDDnp and Abz-GFSPFR-EDDnp are cleaved at the Phe-Ser bond, but Abz-RPPGFSPFRQ-EDDnp and Abz-GFSPFRQ-EDDnp are cleaved at the Pro-Phe bond.

Isolation and characterization of five fibrin(ogen)olytic enzymes from the venom of Philodryas olfersii (green snake).

Five distinct fibrin(ogen)olytic proteinases PofibC1, C2, C3, H and S were isolated by gel filtration and ion-exchange chromatographies. PofibC1, C2, C3 and H are metalloproteinases inhibited by ethylenediamine tetracetic acid (EDTA) or 1,10-phenanthroline. Only PofibH had hemorrhagic activity. PofibS is a serine proteinase, inhibited by phenylmethylsulfonyl fluoride (PMSF) or Torresea cearensis trypsin inhibitor (TCTI). All five enzymes were inhibited by dithiothreitol (DTT) or dithioerythritol (DTE). PofibC1 and C2 presented the same mol. wt of 47,000 and are acidic proteins of pI 6.2 PofibC3 is a basic proteinase of pI 8.5 and mol. wt 45,000. The hemorrhagic proteinase PofibH had a mol. wt of 58,000 and pI of 4.6 and PofibS had a mol. wt of 36,000 and pI of 4.5. The five proteinases degraded fibrin and fibrinogen. PofibC1, C2, C3 and H degraded preferentially A alpha-chains while PofibS cleaved concomitantly A alpha and B beta-chains of fibrinogen. None of these enzymes cleaved the gamma-chain of fibrinogen. When correlated with the thrombin delay time, the most active was PofibS, while PofibH and PofibC1 showed almost no activity. The proteinases also differed in the peptide cleavage of B-chain of insulin. Philodryas olfersii venom promoted in vivo a loss of the circulant plasma fibrinogen, as was observed in experiments with rats.

Hydrolytic specificity of three basic proteinases isolated from the venom of Bothrops moojeni for the B-chain of oxidized insulin.

The hydrolytic activity of three basic proteinases isolated from Bothrops moojeni venom was determined on the B-chain of oxidized insulin. The serine proteinases MSP1 and MSP2 cleave the insulin B-chain at identical positions and in the same order of bond cleavage. Cleavage occurs first at the Arg-Gly(22-23) position, followed by hydrolysis of the Lys-Ala(29-30) peptide bond. The metalloproteinase MPB differs from the serine proteinases in cleaving the insulin B-chain very rapidly at four positions: Ser-His(9-10), Ala-Leu(14-15), Tyr-Leu(16-17) and Phe-Phe(24-25).

Proteolytic specificity of moojeni protease A isolated from the venom of Bothrops moojeni.

Moojeni protease A, a proteolytic enzyme isolated from Bothrops moojeni venom, hydrolyzes type I collagen, gelatin, fibrinogen, fibrin and the B-chain of oxidized insulin. The proteinase cleaves the A alpha-chain faster than the B beta-chain of human fibrinogen and shows no effect on the gamma-chain. Fibrin solubilization appears to occur from the hydrolysis of the alpha-polymer and unpolymerized alpha-chain. The enzyme cleaves the Ala(14)-Leu(15) bond of the oxidized insulin B-chain most rapidly, followed by splitting the Ser(9)-His(10) bond. The Tyr(16)-Leu(17) and Gly(20)-Glu(21) cleavage sites were hydrolyzed slightly more slowly, while the peptide bonds His(5)-Leu(6), His(10)-Leu(11), Glu(21)-Arg(22), Gly(23)-Phe(24) and Phe(24)-Phe(25) were more resistant to the enzyme attack. Small synthetic peptides were not hydrolyzed by moojeni protease A.

Muscular lesions induced by a hemorrhagic factor from Bothrops neuwiedi snake venom.

The local tissue effects of crude Bothrops neuwiedi snake venom and of its hemorrhagic factor (NHF) were studied on mouse tibialis anterior muscle in vivo. After 6 h, 8 days and 6 weeks the muscles were examined in paraffin sections stained with hematoxylin and eosin. Both NHF and crude venom produced hemorrhage and myonecrosis, later followed by muscle fiber regeneration. Intramuscular arteries also suffered necrosis. The minimal dose of NHF necessary to produce detectable hemorrhage and myonecrosis was 50 ng, while the minimal venom dose needed to produce the same effect was 20 times higher. The results indicate that NHF is one of the major factors responsible for the local effects of B. neuwiedi venom.