The Enzymatic Degradation of Heme Proteins into Bile Pigments.

VI The Substrate Specificity of the Enzyme, Especially the Role of Haptoglobin in the Enzymatic Degradation of Hemoglobin

抄録

1) The substrate specificity of the enzyme capable of degrading pyridine-hemichromogen into a direct precursor of biliverdin was reported.
2) Hemoglobin-haptoglobin complex is the direct substrate, while free hemoglobin is almost inactive in this enzyme system.
3) Free hematin and protoporphyrin are quite inert as the substrate.
4) The possible role of haptoglobin in the enzymatic degradation of hemoglobin to bile pigments in vivo is also discussed.
This investigation was supported in part by the Scientific Research Fund of the Ministry of Education of Japan.