Hydrogen ion titration and amino acid analysis of hemocyanin from the spiny lobster Jasus edwardsii.

Potentiometric and spectrophotometric titrations, isoelectric focusing and amino acid analyses, have been made on the hemocyanin from Jasus edwardsii. Counts of acidic neutral and alkaline groups were made from the titrations, enabling comparisons to be made with the amino acid analysis. Thermodynamic analysis of the data indicated that changes in the native protein structure took place at pH 4.0, 8.4 and 10.7. These observations are discussed in terms of dissociation, shifts in pK and conformational changes in the protein.