Fig. 5. Equilibrium-saturation binding of [¹²⁵I]-labelled sperm plasma membrane GSTs (^*GST) to immobilised SZP. SZP (1 µg/well) was immobilised on microtitre plates and [¹²⁵ I]-labelled sperm plasma membrane GSTs were allowed to bind under different conditions. (a) Moles of total sperm plasma membrane GSTs bound to SZP; (b) specific binding of GSTs, which equals total binding (a) minus non-specific binding (c); (c) moles of total sperm plasma membrane GSTs bound to SZP after blocking with 100 mM cold GST. Data are means±s.e.m.