Haem degradation in human haemoglobin in vitro. Separation of the contribution of the alpha- and beta-subunits.
Human haemoglobin was prepared containing [14C]haem in either the alpha- or the beta-subunits. Coupled oxidation of such hybrid haemoglobins with ascorbate and O2 showed that the biliverdin produced by the alpha-subunits contained approx. 55% alpha-isomer and 45% beta-isomer, whereas that produced by the beta-subunits contained approx. 75% alpha-isomer and 25% beta-isomer. Coupled oxidation of isolated alpha- and beta-subunits gave approx. 70% alpha-isomer, 30% beta-isomer and 78% alpha-isomer, 22% beta-isomer respectively. These results are consistent with calculations of differences in the haem environment in the two subunit types.
D001664:Biliverdine / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007536:Isomerism; D010084:Oxidation-Reduction; D011487:Protein Conformation
D006454:Hemoglobins; D006418:Heme; D001664:Biliverdine