The Combination of Porphyrins with Native Human Globin

The changes in absorbancy and fluorescence yield when porphyrins and native globin react are closely correlated. Quantitative oxamination of these changes shows that they are due to the breakdown of porphyrin dimers. The rates of reaction of proto, meso and hematoporphyrins with native globin have been measured. They are in the order proto>meso>hemato. The rates for the porphyrins are closely similar to those for the corresponding CO-hemes. Thus the iron does not influence the rate of binding of heme to globin. (Author)