An investigation into the toxic principle in eggs of the tick Amblyomma hebraeum

Abstract

A purification procedure involving iso-electric focusing by means of which a toxic principle may be obtained in a pure form from crude egg extracts of Amblyomma hebraeum is described. The molecular mass of the toxin is approximately 10 000 according to sedimentation equilibrium sedimentation, Sodium dodecyl sulphate (SDS) gradient gel electrophoresis and calculations from the amino acid composition. Non-competitive proteinase inhibitory activity was found to be associated with the toxin. Histopathological lesions, observed in guinea-pigs inoculated with crude egg extracts or the purified toxin, included the following : focal areas of necrosis in the liver, with mineralization and oedema of the mucosa of the urinary bladder, and vacuolation of the lining epithelium. The genesis of the lesions in the various organs appears to be vascular.