Purification of carboxypeptidase B by metal chelation affinity chromatography

Norwegian lobster carboxypeptidase B (CPB) was purified in one step using immobilized metal chelate affinity chromatography (IMAC). The separation is based on the property that CPB has a high affinity for metal ions such as Cu2+. The CPB was purified from an hepatopancreas extract containing several endo- and exo-proteolytic activities. Its homogeneity was demonstrated by SDS-electrophoresis and isoelectric focusing in immobilized pH gradients. The implication of hydrophobic interaction between this enzyme and the IDA-Cu2+ gel is postulated.