1867-62-5Relevant academic research and scientific papers
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).
Use of Montmorillonite clay for the synthesis of linear tetrapyrroles and their cyclization to uroporphyrinogens
Pichon, Clotilde,Scott, A. Ian
, p. 4497 - 4500 (1994)
Linear tetrapyrroles, such as the formylbilane (1), were obtained by condensation of α-hydroxymethyldipyrromethanes with α-free dipyrromethanes using Montmorillonite clay as acid catalyst. After reduction of the formyl group, hydroxymethylbilanes were cyc
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
Biosynthesis of Natural Porphyrins: Further Experiments with Hydroxymethylbilane
Battersby, Alan R.,Brereton, Richard G.,Fookes, Christopher J. R.,McDonald, Edward,Matcham, George W. J.
, p. 1124 - 1126 (1980)
It is shown that at low temperatures (as at higher ones) the enzyme deaminase converts porphobilinogen into the unrearranged hydroxymethylbilane (5); there is no evidence for formation of preuro'gen (7) nor for its involvement in porphyrin biosynthesis.
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 22. Vitamin B12; Studies of the Chlorin, Faktor-I, and the Detection of 3-epi-Faktor-I
Battersby, Alan R.,Seo, Shujiro
, p. 3049 - 3052 (2007/10/02)
The chlorin, Faktor-I, is prepared in greater quantity than previously by enzymic methylation of uro'gen-III using a cell-free preparation from Clostridium tetanomorphum.Circular dichroism and 1H n.m.r. spectra are determined on the octamethyl ester of Faktor-I and all the important signals in the n.m.r. spectrum are assigned.An isomeric chlorin is detected in the products from the enzymic runs having properties in accord with its being 3-epi-Fktor-I.
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
Biosynthesis of Porphyrins and Related Macrocycles. Part 16. Proof that the Single Intramolecular Rearrangement leading to Natural Porphyrins (Type-III) occurs at the Tetrapyrrole Level
Battersby, Alan R.,Fookes, Christopher J. R.,Meegan, Mary J.,McDonald, Edward,Wurziger, Hanns K. W.
, p. 2786 - 2799 (2007/10/02)
The unrearranged aminomethylbilane (2) is synthesised by a rational route and is proved to be converted by the enzymes deaminase and cosynthetase, working co-operatively, into uro'gen-III (3).The single rearrangement step established earlier is thus proved to take place at the tetrapyrrole level.Synthesis of singly 13C-labelled bilane (2) followed by its enzymic conversion into uro'gen-III serves to register each of the pyrrole rings of the product relative to the initial bilane.Finally, methods for synthesis of the bilane are developed in two different doubly 13C-labelled forms to allow the following key points to be established largely by 13C n.m.r. spectroscopy: (a) as the bilane system is converted into uro'gen-III, intramolecular rearrangement of the terminal ring D occurs, and (b) the linear tetrapyrrole is converted intact into uro'gen-III.Syntheses of -, and -uroporphyrin octamethyl ester are described together with improved h.p.l.c. conditions for the separation of isomeric coproporphyrin tetramethyl esters.
Biosynthesis of Porphyrins and Related Macrocycles. Part 15. Chemical and Enzymic Formation of Uroporphyrinogen Isomers from Unrearranged Aminomethylpyrromethane: Separation of Isomeric Coproporphyrin Esters
Battersby, Alan R.,Buckley, Dennis G.,Johnson, Dawid W.,Mander, Lewis N.,McDonald, Edward,Williams, D. Clive
, p. 2779 - 2785 (2007/10/02)
The unrearranged pyrromethane (1) is transformed chemically mainly into uro'gen-I with a smaller amount of uro'gen-IV but only traces of uro'gen-III are formed.Uro'gen-I is produced via a tetrapyrrolic (bilane) intermediate and when the diaminase-cosynthetase enzyme system from Euglena gracilis is present, this intermediate is converted into uro'gen-III.The rearrangement step for this conversion has the same characteristics found earlier for the natural biosynthetic process from porphobilinogen.Pyrromethane (1) is not a direct biosynthetic precursor of uro'gen-III and reasons are advanced why this is understandable.Methods are developed based on high pressure liquid chromatography for the separation of all four isomeric coproporphyrin esters.
