The alignment of these transcripts showed a high identity (94%) for the signal peptide, propeptide and mature peptide. Sequence alignment of predicted protein also revealed a high structural conservation, showing a score of 96%. Besides this score, the propeptide sequence showed a deletion of a conserved Asp residue, which might reflect differences in the spectrum of biological activity (data not shown). The tryptophyllins were first isolated from P. dacnicolor ( Meneses et al., 2011), and they belong to a large family of peptides with a conserved Trp residue selleck compound at position P2 of the active peptide, and a Pro residue at the N-terminal domain. Asynthetic replicate of tryptophyllin-1, a
member of this family, the peptide PdT-1,
was shown to be a potent myoactive agent, relaxing mammalian arterial smooth muscle and contracting Pictilisib research buy small intestinal smooth muscle ( Chen, 2004). We describe here two contigs and one singlet homologous to tryptophyllin. One of them TP01 showed similarity to sauvatide, which is a myotropic peptide from P. sauvagii ( Wang et al., 2009), whereas TP02 was similar to P. dacnicolortryptophyllin-1. The alignment of nucleotide sequences allowed observing 88% of similarity between TP01 and sauvatide, and 90% of similarity between TP02 and tryptophyllin-1. The singlet TP03 was 85% similar to aurein, a peptide with antimicrobial and antitumoral properties ( Rozek et al., 2000). Sequence comparison performed using BlastX showed that only TP01 has significant structural conservation that is typical of secreted peptides, mainly characterized by a signal peptide followed by a propeptide and a mature peptide
sequence. The open reading frames of the sequences corresponding to TP02 and the alignment of the deduced amino acid sequences are shown in Supplementary material Fig S3. Bradykinin-related peptides (BRPs) are similar to the nonapeptide Resveratrol bradykinin originally described by Rocha e Silva et al. (1949) as a potent vasodilator. These peptides are expressed in many living organisms, including wasps (Picolo et al., 2010) and anurans including some species ofPhyllomedusa genus ( Brand et al., 2006a and Brand et al., 2006b; Chen and Shaw, 2003; Thompson et al., 2006). A high structural diversity of BRPs in the skin secretions of frogs and toads was described ( Chen et al., 2011). The pharmacological effects induced by BRPs include antagonism of bradykinin effects on smooth muscle, vasodilatation, vasoconstriction, and hyperalgesia ( Conceição et al., 2009; Picolo et al., 2010; Zhou et al., 2009). Two singlet sequences showing similarity to BRPs, coined as BK01 and BK02, were found in our database. BlastX did not show any significant similarity to known sequences for these singlets suggesting also the variability of DNA sequences in addition to the structural peptides variability. Thus the transcripts of P. nordestina may represent new transcripts encoding BRPs.