Multiple bradykinin-related peptides including a novel bradykinin structural variant, (Val(1))-bradykinin, have been identified from the defensive skin secretion of Guenther's frog, Hylarana guentheri by a tandem mass spectrometry method. Subsequently, four different preprobradykinin cDNAs, which encoded multiple bradykinin copies and its structural variants, were consistently cloned from a skin derived cDNA library. These preprobradykinin cDNAs showed little structural similarity with mammalian kininogens and the kininogens from the skin of toads, but have regions that are highly conserved in the kininogens from another ranid frog, Odorrana schmackeri.
View Article and Find Full Text PDFThe electrospray ionisation-ion-trap mass spectrometry (ESI-MS(n)) of selected drug compounds with amine-containing side chains has been investigated. Certain characteristic in-source fragmentations have been observed for these molecules. Sequential product ion fragmentation experiments (MS(n)) have been performed in order to elucidate the degradation pathways for the [M + H](+) ions and their predominant fragment ions.
View Article and Find Full Text PDFWe have isolated a novel bradykinin B(2)-receptor antagonist peptide, kinestatin, from toad (Bombina maxima) defensive skin secretion. Mass spectroscopy established a molecular mass of 931.56 Da and a provisional structure: pGlu-Leu/Ile-Pro-Gly-Leu/Ile-Gly-Pro-Leu/Ile-Arg.
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