Comparative sequence analysis of the N-terminal region of rat, rabbit, and dog haptoglobin β-chains

Abstract 1. 1. Quantitative sequence analysis of a 40-residue segment of the amino-terminal region of the β-chain of haptoglobin isolated from sera of rat, rabbit, and dog was undertaken. 2. 2. All three haptoglobin β-chains aligned precisely with human β-chain with no evidence of deletions or insertions. 3. 3. The % difference in amino acid residues between the haptoglobin β-chains was comparable to that reported for the β-chains of hemoglobin from identical mammalian sources. 4. 4. Human and dog haptoglobin β-chains had carbohydrate attached to asparagine at residue-23 whereas rat and rabbit did not.