Immunochemical properties of the haemocyanins from Buccinum undatum (L.) and Neptunea antiqua (L.)

Abstract

1. 1. Rabbit antiserum to Buccinum undatum haemocyanin cross-reacted with Neptunea antiqua haemocyanin and vice versa, the reaction in each case being one of partial identity. Antiserum to B. undatum haemocyanin also cross-reacted weakly with Colus graeilis haemocyanin, and very weakly with Murex trunculus haemocyanin. 2. 2. Depending upon the pH and the Ca 2+ or Mg 2+ concentrations, the reaction of the haemocyanins with their rabbit antisera resulted in the formation of single or multiple precipitin lines in agar and different equivalence points in the quantitative precipitin assay. 3. 3. Analytical ultracentrifugation and electrophoretic analysis showed that this phenomenon was caused by pH-induced dissociation of the haemocyanins, both whole molecules and their dissociation products being capable of reacting with antisera. 4. 4. An interpretation of the patterns observed in immunoelectrophoresis is given based on the time taken for haemocyanin molecules to dissociate at certain pH values, and the electrophoretic mobilities and diffusion coefficients of the dissociation products.