Hybrids of human A1 and canine haemoglobins have been prepared, namely Hbα2Aβ2Ca and Hbα2Caß2A, and the oxygen equilibria have been studied in comparison with those of the parent molecules. The behaviour of the α2Caß2A hybrid is similar to that of the parent molecules (which are both much alike), although the reverse Bohr effect is somewhat increased. In contrast the α2Aß2Ca hybrid has no reverse Bohr effect, lower oxygen affinity (especially at pH<7) and the equilibrium curve is no longer invariant in shape with pH. It is notable that the normal (or alkaline) Bohr effect is the same for all four molecules. These results emphasize the basic structural similarity of the haemoglobin chains from different species but also point to the specificity of the interaction between the α and β chains from the different haemoglobins.
ASJC Scopus subject areas
- Molecular Biology