Identification of novel CAP superfamily protein members of Echinococcus granulosus protoscoleces

• Published in: Acta tropica Vol. 158; pp. 59 - 67
• Main Authors: Silvarrey, María Cecilia, Echeverría, Soledad, Costábile, Alicia, Castillo, Estela, Paulino, Margot, Esteves, Adriana
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-06-2016
• Subjects: Amino Acid Sequence; Animals; CAP superfamily; Echinococcus granulosus; Echinococcus granulosus - chemistry; Helminth Proteins - chemistry; Helminth Proteins - genetics; Humans; Larva - chemistry; Phylogeny; Proteins; Proteins; CAP superfamily; Echinococcus granulosus
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2016.02.011

•Two novel CAP proteins from the flatworm E. granulosus are described.•Topological analysis indicates the presence of typical CAP motifs with different degree of conservation.•3D deduced structure shows the characteristic folding of CAP proteins.•EgVAL1 and EgVAL2 are expressed at the rostellum region.•Subtle differences among E. granulosus VAL proteins suggest that they could perform different functions.
Echinoccocus granulosus is the causative agent of Cyst Echinococcosis, a zoonotic infection affecting humans and livestock representing a public health and an economic burden for several countries. Despite decades of investigation an effective vaccine still remains to be found. Parasitic cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 proteins (CAPs) have been proposed as vaccine candidates against helmith's infection. In this work we have identified two novel proteins of this superfamily expressed at the protoescoleces larval stage named EgVAL1 and EgVAL2. The open reading frame sequences were deduced. The aminoacidic sequence was analyzed and confronted against already known vertebrate' and helminth's proteins sequences in order to infer putative functions. Immunolocalization studies were also performed. The obtained data supported by immunolocalization studies and homology models suggest that these proteins could be involved in protease activity inhibition.