Longipin: An amyloid antimicrobial peptide from the harvestman Acutisoma longipes (Arachnida: Opiliones) with preferential affinity for anionic vesicles

SAYEGH, RAPHAEL SANTA ROSA; DE FATIMA CORREIA BATISTA, ISABEL; DE MELO, ROBSON LOPES; RISKE, KARIN A.; DAFFRE, SIRLEI; MONTICH, GUILLERMO; DA SILVA JUNIOR, PEDRO ISMAEL

PLOS ONE

PUBLIC LIBRARY SCIENCE

Año: 2016 vol. 11

1932-6203

n contrast to vertebrate immune systems, invertebrates lack an adaptive response and rely solely on innate immunity in which antimicrobial peptides (AMPs) play an essential role. Most of them are membrane active molecules that are typically unstructured in solution and adopt secondary/tertiary structures upon binding to phospholipid bilayers. This work presents the first characterization of a constitutive AMP from the hemolymph of an Opiliones order animal: the harvestman Acutisoma longipes. This peptide was named longipin. It presents 18 aminoacid residues (SGYLPGKEYVYKYKGKVF) and a positive net charge at neutral pH. No similarity with other AMPs was observed. However, high sequence similarity with heme-lipoproteins from ticks suggested that longipin might be a protein fragment. The synthetic peptide showed enhanced antifungal activity against Candida guilliermondii and C. tropicalis yeasts (MIC: 3.8-7.5 μM) and did not interfered with VERO cells line viability at all concentrat