title: Microplate fluorescence protease assays test the inhibition of select North American snake venoms' activities with an anti-proteinase library.
abstract: Snake envenomation is a relatively neglected significant world health problem, designated an orphan disease by the WHO. While often effective, antivenins are insufficient. Could another approach greatly aid inhibition of the venom toxins? New fluorescent substrates for measuring protease activity in microplate assays suitable for high throughput screening were tested and found reproducible with snake venom. Representative North American venoms showed relatively strong proteinase and collagenase, but weaker elastase activities. Caseinolytic activity is inhibited by the nonspecific proteinase inhibitor 1,10-phenanthroline and by EDTA, as is collagenase activity, consistent with the action of metalloproteinases. Both general protease and collagenase assays CV average 3%, and Km measured were above normal working conditions. Using a library of anti -proteinase compounds with multiple venoms revealed high inhibitor activity by three agents with known multiple metalloproteinase inhibitor activity (Actinonin, GM6001, and NNGH), which incidentally supports the concept that much of the degradative activity of certain venoms is due to metalloproteinases with collagenase activity. These results together support the use of microplate proteinase assays, particularly this collagenase assay, in future drug repurposing studies leading to the development of new treatments for those envenomations that have a major proteolytic component in their pathophysiology.
authors.affiliation: Department of Pathology, Oklahoma State University College of Osteopathic Medicine, 1111 W. 17th St. Tulsa, OK 74107, USA. Electronic address: joseph.price@okstate.edu.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Price
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000818:Animals; D000997:Antivenins / Q000494:pharmacology*; D004151:Dipeptides / Q000494:pharmacology; D005453:Fluorescence; D006877:Hydroxamic Acids / Q000494:pharmacology; D045726:Metalloproteases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010618:Phenanthrolines / Q000494:pharmacology; D012909:Snake Bites / Q000188:drug therapy; D012910:Snake Venoms / Q000037:antagonists & inhibitors / Q000633:toxicity*; D012911:Snakes / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D000081:Acetamides; D000997:Antivenins; D004151:Dipeptides; D006877:Hydroxamic Acids; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; C583689:NNGH compound; D010618:Phenanthrolines; D012910:Snake Venoms; D013449:Sulfonamides; D045726:Metalloproteases; C010531:actinonin; C025205:1,10-phenanthroline
keywords: Collagenase; Inhibitors; Metalloproteinase; Protease; Venom