Partial purification and some chemical properties of the sperm chemoattractant from the forcipulate starfish Pycnopodia helianthoides (Brandt, 1835)

Abstract

AbstractThe sperm attractant of the forcipulate starfish Pycnopodia helianthoides has been isolated by sea water extraction from ripe ovaries. After concentration and purification by adsorption and desorption using an Amberlite resin followed by gel filtration chromatography, the most active fractions have been further purified by reverse‐phase and hydrophobic‐interaction chromatography. A relative purification of 2 × 105 was obtained. Exposure of the partially purified attractant to temperature extremes and enzymes reveals that the molecule is heat and freeze‐thaw stable and that it is degraded by the proteases trypsin, chymotrypsin, and pronase. Four different procedures used to determine molecular size produce the same estimate of about 12 kD. The attractant is retarded during Sephadex G‐25 chromatography and does not run as a tight band on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). These results suggest that the sperm attractant of this starfish is a small protein. © 1992 Wiley‐Liss, Inc.