NOVEL UPERIN PEPTIDES FROM THE DORSAL GLANDS OF THE AUSTRALIAN FLOODPLAIN TOADLET UPEROLEIA-INUNDATA

The dorsal glandular extract of the floodplain toadlet Uperoleia inund ata contains more than 50 peptides: we report the amino acid sequences and bioactivity data of 13 of these. The peptides have been sequenced by using a combination of mass spectrometry and automated Edman seque ncing. Ten of the peptides have been synthesized in order to confirm t heir structures, and to enable bioassays to be carried out. Ten peptid es are host-defence agents, including (i) a powerful new neuropeptide of the tachykinin family which we name uperin 1.1 [pGluAlaAspProAsnAla PheTyrGlyLeuMet(NH2)], and (ii) nine antibiotic peptides including fiv e uperins 2 [e.g. uperin 2.1, heAlaLysLysValValGlyGlyIleArgAsnAlaLeuGl yIle(OH)], three uperins 3 [e.g. uperin 3.1, euAspAlaPheArgLysIleAlaTh rValValLysAsnValVal(NH2)] and uperin 4.1 ySerPheIleHisLysValValSerAlaI leLysAsnValAla(NH2)]. The function of the three other characterized pe ptides in the amphibian integument is not known, viz. (i) uperin 5.1 [ PheGlnPheValAsnProSerAspIleValPheGlySer(OH)] and (ii) the two uperins 6 [e.g. uperin 6.1, GlyLeuAlaGlyAlaIleSerSerAlaLeuAspLys erGlnLeuIleLy sAsnTyrAlaLysLysLeuGlyTyrProArg(OH)].