ISOLATION AND IMMUNOCYTOCHEMICAL CHARACTERIZATION OF 3 TACHYKININ-RELATED PEPTIDES FROM THE MOSQUITO, CULEX SALINARIUS

Three myotropic peptides belonging to the Arg-amide insect tachykinin family were isolated from whole-body extracts of the mosquito, Culex s alinarius. The peptides, APSGFMGMR-NH2, APYGFTGMR-NH2 and APSGFFGMR-NH 2 (designated culetachykinin I, II, and III) were isolated and purifie d on the basis of their ability to stimulate muscle contractions of is olated Leucophaea maderae hindgut. Biologically inactive methionine su lfoxides of two of the three peptides were isolated using an ELISA sys tem based upon antiserum raised against APYGFTGMR-NH2 and identified w ith mass spectrometry. Immunocytochemistry localized these peptides in cells in the brain, antennae, subesophageal, thoracic and abdominal g anglion, proventriculus and midgut. Nerve tracts containing these pept ides were found in the median nerve of the brain, central body, nervi corpus cardiaci, cervical nerve, antennal lobe and on the surface of t he midgut.