title: Fibrinogenolytic proteases from the venoms of juvenile and adult northern Pacific rattlesnakes (Crotalus viridis oreganus).
abstract: 1. Venoms of Crotalus viridis oreganus show marked ontogenetic variation in protease activity. Adult venoms are approximately five-fold higher in protease (caseinolytic) activity. 2. Of seven potential protease inhibitors, only EDTA and 1,10-phenanthroline caused a significant decrease in protease activity. Responses of juvenile and adult venoms were essentially equivalent, and attempts at recovery of protease activity of EDTA-treated venoms by the addition of Ca2+ or Zn2+ were unsuccessful. 3. Gel filtration resolved two proteases from juvenile and subadult venoms with approximate M(r) of 100,000 and 78,000. Four proteases were resolved from adult venom, and M(r) estimates were 78,000, 61,000, 35,000 and 19,000. 4. Proteases from juvenile and adult venoms showed fibrinogenolytic activity, each producing some unique degradation products. 5. The occurrence of three "new" proteases in adult venom produced the ontogenetic increase in activity seen in the crude venoms.
authors.affiliation: Department of Biological Sciences, University of Northern Colorado, Greeley.
authors.forename: S P
authors.initials: SP
authors.lastname: Mackessy
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D002850:Chromatography, Gel; D003435:Crotalid Venoms / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D008970:Molecular Weight; D010618:Phenanthrolines / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D012911:Snakes / Q000254:growth & development* / Q000378:metabolism
chemical_list: D003435:Crotalid Venoms; D010618:Phenanthrolines; D011480:Protease Inhibitors; D005340:Fibrinogen; D010450:Endopeptidases; C025205:1,10-phenanthroline