These lesson slides only provide an outline.
You must study miyglobin and hemoglobin using a Biochemistry textbook.
Protein formed by
each of them is
similar to myoglobin.
Myoglobin and Hemoglobin structure
- Differences in iron oxydation.
- Effect of amino acid moiety on Fe-CO affinity.
- Switch between taut “T” and relaxed “R” state.
Myoglobin saturation curve
Hemoglobin saturation curve
Hb affinity curve for different human populations.
Fetal Hb affinity .
Modulators of Hb-O2 affinity
Stabilizers of T form favour the release of oxygen so the deoxy-Hb:
- 2,3 BPG;
- Low pH;
- Increase in CO2 (Bohr effect).
Physiological relevance of Bohr effect
In the tissue the increase in [CO2] leads to a pH decrease
CO2 +H2O → HCO3- + H+
At low pH ionic interaction between some amino acids is favoured (Es His 146 Asp 94) and the T form is stabilised.
CO2 directly binds the free amino group forming carbamate adducts stabilizing T form and contributing about 25% of CO2 overall transportation.
Progetto "Campus Virtuale" dell'Università degli Studi di Napoli Federico II, realizzato con il cofinanziamento dell'Unione europea. Asse V - Società dell'informazione - Obiettivo Operativo 5.1 e-Government ed e-Inclusion