Hemoglobin Binding Capacity of Isolated Haptoglobin Polypeptide Chains

The constituent polypeptide chains of haptoglobin were isolated under mild acid conditions and tested by gel filtration for the ability to bind hemoglobin. It was found that the β chain retained considerable binding capacity compared with minimal activity associated with the α chain. These findings allow a correlation between the structure and function of the haptoglobin molecule and suggest that some rare variant phenotypes of haptoglobin which appear to show anomalous binding behavior may be attributed to changes within the β chain.