Fig. 1. SALMFamide-like immunoreactivity in whole-body extracts of Echinus esculentus. The graphs show SALMFamide-like immunoreactivity in a 40% ACN/TFA Sep-Pak eluate (A,B) and a 60% ACN/TFA eluate (C,D) after HPLC fractionation using a gradient of ACN/TFA indicated by the line. HPLC fractions were radioimmunoassayed for both S1-(A,C) and S2-(B,D) immunoreactivity using the antisera SLII and BGI, respectively. The 40% Sep-Pak eluate contains two S2-immunoreactive peaks, 1 and 2 (B), which are weakly immunoreactive with the S1 antiserum SLII. The 60% Sep-Pak eluate also contains two S2-immunoreactive peaks, 3 and 4 (D), which are weakly immunoreactive with the S1 antiserum SLII. The elution times of peaks 2 and 3 are the same so they may contain identical immunoreactive peptides. The SLII antiserum also detects a few minor immunoreactive peaks, which elute before or after the major peaks 1, 2, 3 and 4.