A Koelliker hemoglobin in chick erythrocytes.

1. Adult chicken hemoglobins were analysed by ion exchange chromatography and isoelectric focusing and a minor hemoglobin fraction (HbK) was isolated. 2. Analysis of the constituent chains shows that HbK differs from the two major hemoglobins HbA and HbD in the alpha globin. 3. The amino acid composition, the tryptic peptide maps, the results of carboxypeptidase digestion and the functional properties show that the HbK alpha globin is quite similar to that of HbA except that the C-terminal amino acid Arg 141 is lacking. 4. HbK must then be considered a Koelliker-type hemoglobin.