Isolation and characterization of a coagulation factor Xa inhibitor from black fly salivary glands.
We have discovered and characterized a novel coagulation factor Xa inhibitor from the salivary gland of the black fly, Simulium vittatum. Salivary glands were surgically dissected from the flies and a crude salivary gland extract was tested for inhibition of a number of coagulation assays. The gland extract inhibited both thrombin and factor Xa. To purify further the factor Xa inhibitor, a factor Xa affinity column was utilized. Final purification of the black fly factor Xa inhibitor was achieved by reverse-phase C8 microbore high pressure liquid chromatography. Inhibition of factor Xa was nearly stoichiometric by the purified inhibitor with no inhibitor of thrombin detected. SDS-polyacrylamide gel electrophoresis indicated the inhibitor had a molecular weight of 18,000 and sequence analysis of the inhibitor revealed a blocked amino terminus. These data indicate that the blood-sucking black fly has evolved a highly potent inhibitor of mammalian coagulation factor Xa to disrupt its host normal hemostatic clotting mechanisms.
Jacobs
J W
JW
Department of Biological Chemistry, Merck Sharp & Dohme Research Laboratories, West Point, PA.
Cupp
E W
EW
Sardana
M
M
Friedman
P A
PA
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000990:Antithrombin III / Q000737:chemistry / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004175:Diptera / Q000032:analysis*; D065427:Factor Xa Inhibitors; D008970:Molecular Weight; D012469:Salivary Glands / Q000737:chemistry
D000596:Amino Acids; D065427:Factor Xa Inhibitors; D000990:Antithrombin III