title: An illustration of the use of isotopes: the biosynthesis of porphyrins.
abstract: In this article, David Shemin, who is now in retirement, describes how in 1944 he ingested 66 g of 15N-labeled glycine in order to determine the half-life of hemoglobin and other blood proteins. The ramifications of the experiment led to the unravelling of the biosynthesis of porphyrins and the role of glycine and alpha-aminolevulinic acid in heme, vitamin B12 and chlorophyll synthesis.
authors.forename: D
authors.initials: D
authors.lastname: Shemin
mesh_terms: D002250:Carbon Radioisotopes; D006801:Humans; D007553:Isotope Labeling / Q000379:methods*; D009587:Nitrogen Isotopes; D011166:Porphyrins / Q000096:biosynthesis*
chemical_list: D002250:Carbon Radioisotopes; D009587:Nitrogen Isotopes; D011166:Porphyrins