The Structure, Function and Inhibitory Action of Porphyrins

Abstract

The necessity of hematin for growth of Hemophilus influenzae was used to throw light on the synthesis, action and specificity of various porphyrin compds. This organism inserts iron only into protoporphyrin and requires vinyl groups to do this. Iron-free porphyrins lacking vinyl groups inhibit the growth-promoting influence of iron porphyrins. The porphyrins must compete for the combination with the specific proteins of the heme enzymes, and the combination may occur by interaction of the ionized proprionic acid porphyrin side chains with basic groups of the protein. Iron porphyrins are catalysts which make O2 available to the organism.