Fibrinolytic and fibrinogenolytic metalloproteinase that hydrolyzes the Aalpha-chain and more slowly the Bbeta-chain of fibrin and fibrinogen. Its fibrinolytic activity is direct, without any plasminogen activation. Also hydrolyzes casein and B-chain of oxidized insulin. Inhibits ADP-induced and collagen-induced platelet aggregation. Shows low hemorrhagic activity. Cleaves the plasma proteinase inhibitors alpha(2)-macroglobulin (A2M) and pregnancy zone protein (PZP), and is inhibited by them. The metalloprotease has no strict P1-P1' specificity requirement. Hydrolysis at sites with a Pro residue at P1 is observed with bradykinin, substance P, PZP and alpha chain fibrinogen (FGA) (PubMed:11910177). Poor inhibitor of platelet aggregation. The disintegrin inhibits the adhesion of the alpha-4/beta-1 (ITGA4/ITGB1) integrin to VCAM-1. Inhibition on alpha-2b/beta-3 (ITGA2B/ITGB3) is low (By similarity). Binds 1 zinc ion per subunit. Fibrinolytic and caseinolytic activities are inhibited by Cd(2+), Cu(2+) and Co(2+) ions. Not inhibited by Mg(2+), Ca(2+) and Ba(2+). Also inhibited by EDTA, EGTA and 1,10-phenanthroline. Monomer (metalloproteinase). Heterodimer; disulfide-linked (disintegrin) (By similarity). Expressed by the venom gland. 2 lebetase isoforms have been isolated designated lebetase I (22.719 Da, pI 5.0) and lebetase II (22.912 Da, pI 5.3). Disintegrin VLE5A does not interact with the collagen-binding alpha-1/beta-1 (ITGA1/ITGB1) and alpha-2/beta-1 (ITGA2/ITGB1) integrins. The disintegrin belongs to the dimeric disintegrin subfamily. Belongs to the venom metalloproteinase (M12B) family. P-II subfamily. P-IIe sub-subfamily.