IXODES-SCAPULARIS - SALIVARY KININASE ACTIVITY IS A METALLO DIPEPTIDYL CARBOXYPEPTIDASE

Saliva and salivary gland homogenates of Ixodes scapularis contain a d ipeptidyl carboxypeptidase activity that accounts for the previously d escribed salivary kininase activity of this tick. Reversed phase HPLC and laser desorption mass spectrography of the reaction product!; iden tified bradykinin fragment 1-7 and 1-5 as being produced subsequent to incubation of purified salivary kininase with bradykinin. The activit y was inhibited by captopril and EDTA and was activated by cobalt and manganese, a behavior similar to that displayed by angiotensin-convert ing enzymes of vertebrate and invertebrate origins. (C) 1998 Academic Press.