Heme biosynthesis in intermittent acute prophyria: decreased hepatic conversion of porphobilinogen to porphyrins and increased delta aminolevulinic acid synthetase activity.
Hepatic conversion of porphobilinogen to porphyrins was less than 50% of control levels in human subjects with the genetic disease, intermittent acute porphyria. This relative block in heme biosynthesis may be relevant to a concomitant 6- to 10-fold elevation in delta-aminolevulinic acid synthetase activity, since this first and rate-controlling enzyme in the biosynthetic pathway is subject to negative feedback regulation by the end product, heme. A micro-radio-chemical assay of delta-aminolevulinic acid synthetase, and some of its applications, are described.
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002247:Carbon Isotopes; D046508:Culture Techniques; D004912:Erythrocytes / Q000378:metabolism; D006418:Heme / Q000096:biosynthesis*; D006801:Humans; D007982:Levulinic Acids; D008099:Liver / Q000201:enzymology*; D051379:Mice; D011164:Porphyrias / Q000201:enzymology*; D011166:Porphyrins; D013386:Succinates
D002247:Carbon Isotopes; D007982:Levulinic Acids; D011166:Porphyrins; D013386:Succinates; D006418:Heme; D000217:Acyltransferases