Fig. 4. Effects of sulphated versus non-sulphated competitors on binding of ¹²⁵I-mZP2 to expressed proacrosin peptide. (A) Typical autoradiograph of a western blot containing the expressed 32 kDa peptide probed with ¹²⁵I-mZP2 in the presence of a variety of competitors (all at 1 mg/ml). Suramin, dextran sulphate and fucoidan are all effective competitors whereas dextran and soybean trypson inhibitor (SBTI) are ineffective. (B) Relative efficacy of different competitors in preventing binding of ¹²⁵I-mZP2 to the 32 kDa peptide. Binding is expressed as a percentage relative to controls containing no competitor (taken as 100%). Results are means ± s.e.m. of 3-4 separate experiments.