Combination of Globin and It's Derivatives with Hemins and Porphyrins*

Abstract

Apohemoglobin with helical content of 50% was prepared and used in the experiments to combine hemins or porphyrins. Protohemin, protoporphyrin, hematoporphyrin as well as etiohemin and hemindimethylester, were shown to combine with globin, while protoporphyrin-dimethylester and etioporphyrin were not. Among the modified apohemoglobins, acetylated globin was shown to bind hematin, but not protoporphyrin, while azoglobins had no capacity to combine with heroins and porphyrins. PGMB-globin, though unstable, was shown to have an ability to bind hemins and porphyrins like untreated apohemoglobin. From these results the importance of the linkage between the carboxyl groups of porphyrin and the amino groups of globin was discussed.