M. Grinstein, M. Kamen, C. Moore
May 1, 1949
Citations
0
Influential Citations
29
Citations
Journal
The Journal of biological chemistry
Abstract
Isotopic studies have demonstrated that glycine is used in the biosynthesis of hemoglobin. Glycine has been tagged in one of three ways: (a) with N’” in the amino group (l-3), (b) with Cl4 in the a-methylene carbon position (4), and (c) with Cl4 in the carboxyl group (5). When any of these three forms of glycine is fed to animals, the isotope is incorporated into hemoglobin, but interesting differences have been observed in the distribution of the isotope between the pigment and protein portions of the molecule. For instance, Shemin and Rittenberg, using glycine labeled with NIB, found greater concentrations of the heavy nitrogen in hemin than in red blood cell protein (2). Similarly, Altman and his associates observed that when the methylene carbon of glycine is tagged 7 to nearly 10 times as much Cl4 appear in hemoglobin protoporphyrin as in globin (4). On the other hand, recent observations in t,his laboratory have shown that when glycine containing Cl4 in the carboxyl group is administered the radioactive carbon is synthesized into globin but cannot be demonstrated in protoporphyrin (5). The experiments to be described in this report were designed (1) to confirm the demonstration that the carboxyl carbon of glycine is used for the biosynthesis of globin but not protoporphyrin, (2) to determine whether globin within the red cell participates in protein interchange, and (3) to discover whether coproporphyrin I isolated from the urine and feces after the tagged glycine was fed would contain Cl* even if the hemoglobin protoporphyrin did not.