The Amino Acid Sequence of the γ Chain of Human Fetal Hemoglobin*

The 146 amino acid residues of the γ chain of human fetal hemoglobin have been placed in sequence. The fetal hemoglobin for this investigation was isolated chromatographically from umbilical cord blood. The α and γ chains were separated prior to the determination of sequence. For the determination of the sequence, peptides were produced by individual hydrolyses with trypsin, chymotrypsin, or pepsin. The sequence of the individual peptides was determined largely through the application of the Edman degradation. The differences between the γ chains of human fetal hemoglobin and the β chains of human adult hemoglobin are responsible for the differences in the properties of the two molecules.