1867-62-5Relevant articles and documents
Direct assay of enzymes in heme biosynthesis for the detection of porphyrias by tandem mass spectrometry. Porphobilinogen deaminase
Wang, Yuesong,Scott, C. Ronald,Gelb, Michael H.,Turecek, Frantisek
, p. 2606 - 2611 (2008)
We report a new assay of human porphobilinogen deaminase (PBGD). Deficiency in this enzyme activity causes acute intermittent porphyria, the most common disorder of heme biosynthesis. The assay involves incubation of blood erythrocyte lysate with porphobilinogen, the natural PBGD substrate. Two subsequent enzymes in the heme biosynthetic pathway, uroporphyrinogen III synthase and uroporphyrinogen decarboxylase, are deactivated by heating so that their activity does not interfere with the PBGD assay. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) is used to monitor the production of uroporphyrinogen I and thus measure the PGBD activity. A simple and efficient workup using liquid-liquid extraction with >90% product recovery was employed to avoid separation by liquid chromatography. The assays show good reproducibility (±3.3%) and linear dependence of the uroporphyrinogen I formation on incubation time and protein amount. The Km of PGBD for porphobilinogen was measured as 11.2 ± 0.5 μM with Vmax of 0.0041 ± 0.0002 μM/min·mg of hemoglobin). The coefficient of variation of PBGD activity among several unaffected individuals (12%) is significantly lower than the decrease due to acute intermittent porphyria (50%).
The carbon-13 and nitrogen-15 nuclear magnetic resonance spectra of uroporphyrinogens I and III
Burton, Gerardo,Fagerness, Paul E.,Jordan, Peter M.,Scott
, p. 2721 - 2725 (1980)
Due to their sensitivity to light and air, porphyrinogens are not normally isolated, but are routinely analyzed by oxidation to the corresponding porphyrin. We report herein the 13C- and 15N-NMR spectra of uroporphyrinogens I and III in their "native state", multiply labelled with 13C and 15N, and at natural abundance (13C only).
Biosynthesis of Porphyrins and Related Macrocycles. Part 18. Proof by Spectroscopy and Synthesis that Unrearranged Hydroxymethylbilane is the Product from Deaminase and the Substrate for Cosynthetase in the Biosynthesis of Uropophyrinogen-III
Battersby, Alan R.,Fookes, Christopher J. R.,Gustafson-Potter, Kerstin E.,McDonald, Edward,Matcham, George W. J.
, p. 2427 - 2444 (1982)
When the enzyme deaminase acts alone on porphobilinogen, it releases a tarnsient intermediate into the medium which is unaffected by further treatment with a large excess of deaminase.The intermediate undergoes rapid ring-closure chemically (t1/2/su
Synthesis of substrate analogs of methyltransferases in the vitamin B12 biosynthetic pathway and characterization of their enzymatic products
Pichon-Santander, Clotilde,Santander, Patricio J.,Scott, A. Ian
, p. 3904 - 3922 (2007/10/03)
The specificity toward substrate analogs of the first two methyltransferases in the vitamin B12 biosynthetic pathway was probed with 15 synthetic porphyrinogens. Several novel methylated chlorins and isobacteriochlorins were isolated and charac
Biosynthesis of Porphyrins and Related Macrocycles. Part 17. Chemical and Enzymic Transformation of Isomeric Aminomethylbilanes into Uroporphyrinogens: Proof that Unrearranged Bilane is the Preferred Enzymic Substrate and Detection of a Transient Intermed
Battersby, Alan R.,Fookes, Christopher J. R.,Gustafson-Potter, Kerstin E.,McDonald, Edward,Matcham, George W. J.
, p. 2413 - 2426 (2007/10/02)
Six isomeric aminomethylbilanes have been built by unambiguous synthesis.One bilane has the unrearranged structure corresponding to straightforward head-to-tail assembly of four units of porphobilinogen; the other five bilanes have one or more of the pyrr
