Cytotoxic, thrombolytic and edematogenic activities of leucurolysin-a, a metalloproteinase from Bothrops leucurus snake venom.
Leucurolysin-a (leuc-a), a 23 kDa non-hemorrhagic metalloproteinase, is found in venom of the viper Bothrops leucurus. Here, we examine the biological consequences of leuc-a, including thrombolytic activity, direct effects on endothelial cells in culture and edematogenic activity in vivo. We demonstrate fibrinolytic activity of leuc-a, in which the protease specifically degrades alpha, beta, and gamma-gamma chains. While not causing hemorrhaging, leuc-a does cause thrombolytic activities in whole blood clots. Endothelial cells are highly resistant to leuc-a in culture. Cell viability suffered only when cells were exposed to large quantities of the protease. Nevertheless, leuc-a induces changes in cell morphology. The impact of leuc-a on cell adhesion was confirmed by an adhesion assay, in which cell adhesion to fibronectin decreased due to leuc-a. This mild cellular impact is unlike that of crude venom, where lower concentrations triggered cell death and a greater reduction in cell adhesion. Also, leuc-a increased microvessel permeability with marked edema in mice peritoneum and foot pads. These effects are similar to those of other P-I class SVPMs. These in vivo effects were weaker when crude venom was tested. In conclusion, albeit not showing significant hemorrhagic activity, leuc-a can induce a prominent edema which appears to be significant in the local effects observed after B. leucurus venom accidents.
Gremski
L H
LH
Medical Clinic Discipline, Department of Medicine, UNIFESP, São Paulo, SP, Brazil.
Chaim
O M
OM
Paludo
K S
KS
Sade
Y B
YB
Otuki
M F
MF
Richardson
M
M
Gremski
W
W
Sanchez
E F
EF
Veiga
S S
SS
D000704:Analysis of Variance; D000818:Animals; D017837:Bothrops / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D003435:Crotalid Venoms / Q000201:enzymology / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity*; D004487:Edema; D005337:Fibrin / Q000378:metabolism; D005342:Fibrinolysis / Q000187:drug effects*; D005353:Fibronectins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D045726:Metalloproteases / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity*; D055806:Microvessels / Q000378:metabolism; D011817:Rabbits; D013917:Thrombin / Q000378:metabolism
D003435:Crotalid Venoms; D005353:Fibronectins; D005337:Fibrin; D045726:Metalloproteases; D013917:Thrombin