One peptide encoded by DM01 showed the Tyr-Ala-Ser-Gly-Tyr-Pro-Ser sequence.
There placement of a Phe by a Ser residue is not a conservative substitution, and it was not observed in other known dermorphins sequences. For this reason, an additional analysis using ProtParam webtool (http://web.expasy.org/protparam/) was conducted. In spite of the substitution of the non-polar amino acid residue (Phe) for a polar one (Ser), no change in the partial charge of the peptide could be detected (data not shown). Besides this amino acid substitution, all peptides encoded by both contigs have a C-terminal portion that is liable to amidation, which increases the peptide affinity for the receptor (Melchiori and Negri, 1996). But there is no clear indicative that the amino acid substitution observed Veliparib in vitro here influence the biological activity of the peptide encoded by DM01 contig. The analysis of the singlet DM03 also showed a similarity (identity) of about 95% to demorphin-2 (GenBank ID: M18030.1). NVP-BEZ235 mouse The structure of the deduced transcriptional product showed five copies of propeptide and mature peptide, and the marked difference was the absence of a signal peptide. This may be an indicative of
the existence of a precursor for putative intracellular peptides that, in on our view, is a novelty that deserves further investigation. The deduced amino acid sequences of all open reading frames of dermorphin contigs, as well as ESTs, and the respective sequences alignment are shown (see Supplementary material Figs. S1 and S2). Among several well-known families of antimicrobial peptides (AMPs), the superfamily of dermaseptins grouped several families, which include the phylloseptin family. Precursors mRNAs of dermaseptins have unique pattern with highly similar N-terminal preprosequences followed by a cleavage recognition site (KR) typical of prohormone processing signal and variable C-terminal domains encoding mature antimicrobial peptides (Amiche et al.,
1999; Nicolas et al., 2003). Dermaseptins strictu sensu family see more comprises peptides typically of 27–34 amino acid residues, with 3–6 Lys residues and a highly conserved Trp residue in the third position ( Zairi et al., 2009). They were the first vertebrate peptide to be described showing a potent antimicrobial activity against filamentous fungi, and that is implicated in severe opportunistic infections caused by immunodeficiency syndrome and immunosuppressive drug therapy ( Amiche et al., 1994). Besides the antimicrobial activity another biological properties of dermaseptins was demonstrated, namely the chemotactic properties of a peptide isolated from Pacmedusa dacnicolor DRS-DA4upon leukocytes ( Auvymet et al., 2009), and the antitumoral and angiostatic activities of dermaseptins B2 and B3 ( Van Zoggel et al., 2012).