title: Kinetic properties of toxic protease inhibitors isolated from tick eggs.
abstract: 1. Egg-toxins from Rhipicephalus evertsi evertsi, Boophilus microplus, Boophilus decoloratus and Hyalomma truncatum were found to be inhibitors of trypsin and in two cases also of chymotrypsin. 2. Fast tight-binding and slow-binding inhibition were observed. 3. Immunological identity of the toxins were assessed with Ouchterlony immunodiffusion and ELISA. 4. The protease content of B. decoloratus and Amblyomma hebraeum tick eggs were determined by a linked enzyme assay. 5. The predictive value of the kinetic constants in inferring a possible physiological role was discussed.
authors.affiliation: Department of Biochemistry, University of Pretoria, Republic of South Africa.
authors.forename: N M
authors.initials: NM
authors.lastname: Vermeulen
authors.forename: G J
authors.initials: GJ
authors.lastname: Viljoen
authors.forename: J D
authors.initials: JD
authors.lastname: Bezuidenhout
authors.forename: L
authors.initials: L
authors.lastname: Visser
authors.forename: A W
authors.initials: AW
authors.lastname: Neitz
mesh_terms: D000818:Animals; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D005260:Female; D007700:Kinetics; D010063:Ovum / Q000032:analysis*; D011480:Protease Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D013045:Species Specificity; D013987:Ticks; D014118:Toxins, Biological; D014361:Trypsin Inhibitors / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D011480:Protease Inhibitors; D014118:Toxins, Biological; D014361:Trypsin Inhibitors; D002918:Chymotrypsin