Metabolism of the Hemin Chromoproteins

Abstract

A comprehensive review of the present state of information on the metabolism of the chromoproteins, particularly hemoglobin, myoglobin and cytochrome c. Advances in the separate fields of study of Fe, porphyrin, globin (protein) and red blood cell metabolism are integrated. Such an approach serves to bring out new orientations with reference to the metabolism of Fe and porphyrins, as well as in the function of the chromoproteins. Areas in which further investigation is needed are indicated. The "imperfections" of homeostasis are discussed, and the need for a more realistic evaluation of metabolism is suggested and embodied in a concept of "metabolic capacity," as contrasted with "basal metabolism." The 7 explanatory figures and 4 tables of summarized data bring out the importance of "negligible" loss of body Fe, the precarious homeostasis of Fe (and the role of ferritin and siderophilin or [beta] 1-pseudoglobulin), the homeostasis of hemoglobin, and recent knowledge of the biosynthesis of hemin acquired with isotopic tracer technics.