Identification and characterization of an antimicrobial peptide of Hypsiboas semilineatus (Spix, 1824) (Amphibia, Hylidae)

Abstract

The multidrug-resistant bacteria have become a serious problem to public health. In this scenery the antimicrobial peptides (AMPs) derived from animals and plants emerge as a novel therapeutic modality, substituting or in addition to the conventional antimicrobial. The anurans are one of the richest natural sources of AMPs. In this work several cycles of cDNA cloning of the skin of the Brazilian treefrog Hypsiboas semilineatus led to isolation of a precursor sequence that encodes a new AMP. The sequence comprises a 27 residue signal peptide, followed by an acidic intervening sequence that ends in the mature peptide at the carboxy terminal. The AMP, named Hs-1, has 20 amino acids residues, mostly arranged in an alpha helix and with a molecular weight of 2144.6 Da. The chemically synthesized Hs-1 showed an antimicrobial activity against all Gram-positive bacteria tested, with a range of 11-46 μM, but it did not show any effect against Gram-negative bacteria, which suggest that Hs-1 may have a selective action for Gram-positive bacteria. The effects of Hs-1 on bacterial cells were also demonstrated by transmission electron microscopy. Hs-1 is the first AMP to be described from H. semilineatus.

Biological Properties of a Novel Multifunctional Host Defense Peptide from the Skin Secretion of the Chaco Tree Frog, Boana raniceps

“…The antimicrobial properties of Figainin 2 were evaluated against pathogenic Gram-negative and Gram-positive bacteria and yeasts (Table 4) On the other hand, this peptide did not show activity against the yeasts C. albicans and C. parapsilosis. Figainin 2 was more active against Gram-positive bacteria, and this property is similar to the ones exhibited by Hylin-a1 from B. albopunctata [36] and by HS-1 from B. semilineata [37], both peptides with hydrophobic ratio higher than 50%. Oppositely, the AMP Raniseptin 1 from B. raniceps which exhibits a less hydrophobic ratio of 44% is more active against Gram-negative bacteria [38].…”

Parallel identification of novel antimicrobial peptide sequences from multiple anuran species by targeted DNA sequencing

“…This method however requires accurate primer design to capture the diversity of AMPs. In general, anuran antimicrobial peptide precursors consist of a highly conserved signal sequence, a negatively charged propeptide and a hypervariable cationic mature region [ 14 – 16 ]. Data on anuran signal sequences pertaining to different families and species are available in a dedicated database, DADP [ 17 ].…”

Cleavage of Peptides from Amphibian Skin Revealed by Combining Analysis of Gland Secretion and in Situ MALDI Imaging Mass Spectrometry

“… 39 This alignment included sequences described in B. punctata ( 9 , 10 ) and in all species of the tribe Cophomantini, subfamily Hylinae. The specific sequences included were the following: eight peptides of B. raniceps (raniseptins), 18 peptides of Boana albopunctata (hylin-1a and Ctx-Ha), 16 peptides of Boana lundii (hylin-b1 and hylin-b2), 17 one peptide of Boana semilineata (Hs-1), 40 and one peptide of B. cinerascens (Cinerascetin-01). 15 For comparison, uncertainties (X) in the peptide sequence identified in our study in B. punctata were either left as Leu or were tentatively assigned to Leu or to Ile based on similarities with the amino acid sequence identified in the same or related species and also on comparisons with synthetic analogues ( Table S4 ).…”