Heme Biosynthesis in Intermittent Acute Porphyria: Decreased Hepatic Conversion of Porphobilinogen to Porphyrins and Increased Delta Aminolevulinic Acid Synthetase Activity
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A micro-radio-chemical assay of delta-aminolevulinic acid synthetase, and some of its applications, are described, and this first and rate-controlling enzyme in the biosynthetic pathway is subject to negative feedback regulation by the end product, heme.Abstract:
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 δ-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 δ-aminolevulinic acid synthetase, and some of its applications, are described.read more
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Book ChapterDOI
11 δ-Aminolevulinic Acid Synthetase
Peter M. Jordan,David Shemin +1 more
TL;DR: δ-Aminolevulinic acid synthetase catalyzes the condensation between glycine and succinyl-CoA, the first key intermediate in the biosynthesis of heme, chlorophyll, and corrin.
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Mortality in patients with acute intermittent porphyria requiring hospitalization: A United States case series
Jennifer B. Jeans,Kay Savik,Cynthia R. Gross,Mary K. Weimer,Irene Bossenmaier,Claus A. Pierach,Joseph R. Bloomer +6 more
TL;DR: The proportionate increase in mortality due to symptomatic AIP was three-fold compared to the general population during the past 50 years, the major cause of the increased mortality was the porphyric attack itself.
Journal ArticleDOI
Regulation of prophyrin biosynthesis. Purification and characterization of -aminolevulinic acid synthase.
TL;DR: Although δ-aminolevulinic acid synthase functions in a regulatory capacity, it apparently lacks some characteristics generally observed with allosteric enzymes.
Book ChapterDOI
Chapter 1 The biosynthesis of 5-aminolaevulinic acid and its transformation into uroporphyrinogen III
TL;DR: This chapter discusses the enzymic synthesis of 5-aminolaevulinic acid and the subsequent three enzyme steps to porphobilinogen, preuroporphyrinogen and uroporphyrinogens III, common to all living systems which synthesize tetrapyrroles.
Journal ArticleDOI
Characterization of the Porphobilinogen Deaminase Deficiency in Acute Intermittent Porphyria: IMMUNOLOGIC EVIDENCE FOR HETEROGENEITY OF THE GENETIC DEFECT
TL;DR: It is hypothesized that the enzymatic defect in the CRIM-positive AIP family resulted from a mutation in the structural gene for PBG-deaminase which altered the catalytic as well as a substrate binding site.