“…Fish β-PVs are made up of a single polypeptide chain of approximately 109 amino acids that contains three EF-hand motifs (AB, CD and EF), of which only two (the CD and EF) have functional cationbinding acid loops 3,4,16,17 . These chains display a complex pattern of IgE linear epitopes that involve intermotif spacers (residues 33-44 joining the AB and CD motifs, and 65-74 linking the CD and EF motifs), acid loops (residues 49-64 and 88-94 on the CD and EF motifs, respectively) and a salmonid-specific region (residues 1-18) 18,19,20,21,22,23,24,25 . Of these, the segment containing residues 33-44 has been described as highly immunoreactive in β-PV from several fish species 3,19,20,24,25 .…”