Involved in oxygen transport from the lung to the various peripheral tissues. Functions as an endogenous inhibitor of enkephalin-degrading enzymes such as DPP3, and may thereby play a role as a regulator of pain and inflammation. Heterotetramer of two alpha chains and two beta chains. Red blood cells. Four allelic beta chains have been found in bovine hemoglobins. A and B alleles were found in Jersey cattle and C and D alleles were found in Angoni cattle (East African short-horn zebu). The sequence shown is that of the allele A. Belongs to the globin family.