Isolation and characterization of a trypsin-like enzyme from the buffalo fly, Haematobia irritans exigua.
The incorporation of soybean trypsin inhibitor (SBTI) into the diet of the buffalo fly, Haematobia irritans exigua (De Meijere), results in increased mortality and reduced fecundity. A trypsin-like enzyme which binds to SBTI was isolated by affinity chromatography on a Sepharose-SBTI column followed by ion-exchange chromatography. The enzyme was inhibited by benzamidine, phenylmethylsulfonyl fluoride, ovomucoid, leupeptin and alpha-2 macroglobulin. The enzyme was not inhibited by EDTA or p-chloromecuribenzoic acid and had a broad pH optimum of pH 7-9. Vaccination of sheep produced antibodies specific for the trypsin-like enzyme which inhibited enzyme activity in vitro but did not affect the survival of flies maintained in in vitro culture.
East
I J
IJ
CSIRO Division of Tropical Animal Production, Long Pocket Laboratories, Indooroopilly, Queensland, Australia.
Allingham
P G
PG
Bunch
R J
RJ
Matheson
J
J
D000818:Animals; D002417:Cattle; D010450:Endopeptidases / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D009117:Muscidae / Q000201:enzymology* / Q000276:immunology; D012756:Sheep / Q000276:immunology; D014357:Trypsin / Q000737:chemistry; D014361:Trypsin Inhibitors / Q000494:pharmacology; D014611:Vaccination
D014361:Trypsin Inhibitors; D010450:Endopeptidases; D014357:Trypsin