| hemoglobin | <cell biology, haematology> Four subunit globular oxygen carrying protein of the erythrocytes of vertebrates and some invertebrates. It is a conjugated protein containing four haem groups and globin. There are two alpha and two beta chains (very similar to myoglobin) in adult humans, the haem moiety (an iron containing substituted porphyrin) is firmly held in a nonpolar crevice in each peptide chain. There are four globin polypeptide chains, designated alpha, beta, gamma, delta in the adult. Each is composed of several hundred amino acids. (08 Mar 2000) |
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| haemoglobin Gower-1 | A Hb of molecular formula ζ2&vepsilon;2, found as a minor Hb in the early embryo; disappears by the third month of pregnancy in favour of haemoglobin Gower-2 and haemaglobin Portland and then by Hb F; the ζ chain has 141 amino acid residues. Synthesis of the ζ chain is deficient in cases of hydrops foetalis. Compare: haemoglobin Gower-2, haemoglobin Portland. (05 Mar 2000) |
| haemoglobin Gower-2 | A normal Hb of molecular formula a2A&vepsilon;2, which is a major Hb component of the early embryo; production of &vepsilon; chains normally ceases at about the third month of foetal development and is replaced by Hb F. Compare: haemoglobin Gower-1, haemoglobin Portland. (05 Mar 2000) |