Aggregation patterns in Cherax destructor hemocyanin: control of oligomer distribution by incorporation of specific...

Recent polyacrylamide gel electrophoresis studies on Cherax destructor hemocyanin have demonstrated the presence of three further constituent fractions in the alkaline dissociation product in addition to the three subunits reported in earlier work. Two of these recently discovered subunits are monomeric with molecular weights around 750000, while the third subunit is of similar size to the previously identified dimeric subunit M3' with a molecular weight near 150 000. The aggregation process is influenced by the presence of calcium ions, particularly in the distribution of hybrid hexameric species. However, the relative proportions, as well as the types of subunits present initially, are of primary importance in determining the oligomer distribution pattern obtained upon reconstitution from alkaline pH to pH 7.8 of selected mixtures of subunits. An additional significant factor in the assembly process has been proposed: the operation of different relative rates of aggregation between different types of subunits. Reconstitution experiments based on these findings substantially explain the complex distribution of oligomeric forms in C. destructor hemolymph.