Hyaluronidase and esterase activities of the venom of the poisonous brown recluse spider

Brown Recluse Spider Venom: Proteomic Analysis and Proposal of a Putative Mechanism of Action

“…PLA 2 s hydrolyze the sn-2 ester bond on L-glycerophospholipids. The action of PLA 2 can generate lysophosphatidic acid or sphingosine-1-phosphate, which are known to induce a series of pathological responses, including pro-inflammatory processes, platelet aggregation and endothelial hyperpermeability [11,54]. PLA 2 in general is implicated in the release of arachidonic acid from cell membranes, and this release has been reported to be indirectly involved in inflammatory responses.…”

“…Arachidonic acid may be released from membrane phospholipids from mast cells, macrophages, monocytes, eosinophils and basophils through the activation of PLA 2 . Arachidonic acid undergoes metabolism via two major pathways: the cyclooxygenase pathway (which produces various prostaglandins and thromboxanes) and the 5-lipoxygenase pathway [53,54]. PLA 2 may modulate vascular smooth muscle tone as well as participating in the long term control of the cell cycle involved in chronic remodeling of the vascular tree [11,54].…”

Extracellular matrix molecules as targets for brown spider venom toxins

“…The presence of a sphingomyelinase D-like enzyme (32-35 kDa) probably associated with necrotic, hemolytic and thrombocytopenic activities triggered by the venoms has also been identified in different Loxosceles species (3,4,6,10,15,16). Other enzymes such as a hyaluronidase have been postulated to be a spreading factor during the lesions (4,17), and protease activities also appear to have some participation in the noxious effects of the venoms (11,(18)(19)(20)(21). Adult plasma components appear to be required for the deleterious effects of the venoms, since a purified putative dermonecrotic toxin diluted in neonate plasma or synthetic buffer did not induce platelet activation, an event that may be responsible for thrombosis, tissue ischemia and dermonecrosis (8).…”

Glycosidases in Venoms

“…Hyaluronidase is found in venom from fish (1,2), hymenoptera (bee, wasp, and hornet), reptiles (snake and lizard) (3,4), and arthropods (scorpion and spider) (5,6). The presence of hyaluronidase in snake venom is shown in Table 1 162 TU AND KUDO (7).…”