Articoli di riviste: "Porphobilinogène"

1

Deybach, J. C., e H. Puy. "Porphobilinogène (PBG) : précurseur de la biosynthèse de l'hème". EMC - Biologie médicale 5, n. 3 (gennaio 2010): 1–4. http://dx.doi.org/10.1016/s2211-9698(10)71427-8.

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Deybach, J. C., e H. Puy. "Porphobilinogène (PBG) : précurseur de la biosynthèse de l'hème". EMC - Biologie Médicale 5, n. 3 (2010): 1–4. https://doi.org/10.1016/s0000-0000(10)51137-9.

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3

Schmitt, C., A. Poli, H. Manceau, H. Puy, L. Gouya e T. Lefebvre. "Acide delta-aminolévulinique et porphobilinogène : précurseurs de la biosynthèse de l’hème". EMC - Biologie Médicale 18, n. 1 (gennaio 2023): 1–7. https://doi.org/10.1016/s2211-9698(22)43395-4.

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4

Mami, I., A. Karras, H. Puy, P. Beaune, É. Thervet e N. Pallet. "Caractérisation des modifications phénotypiques épithéliales rénales induites par l’acide delta aminolévulinique et le porphobilinogène". Néphrologie & Thérapeutique 9, n. 5 (settembre 2013): 380–81. http://dx.doi.org/10.1016/j.nephro.2013.07.356.

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5

Leeper, Finian J., e Martin Rock. "Interaction of analogues of porphobilinogen with porphobilinogen deaminase". Journal of the Chemical Society, Perkin Transactions 1, n. 21 (1996): 2643. http://dx.doi.org/10.1039/p19960002643.

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6

SHOOLINGIN-JORDAN, Peter M., Martin J. WARREN e Sarah J. AWAN. "Discovery that the assembly of the dipyrromethane cofactor of porphobilinogen deaminase holoenzyme proceeds initially by the reaction of preuroporphyrinogen with the apoenzyme". Biochemical Journal 316, n. 2 (1 giugno 1996): 373–76. http://dx.doi.org/10.1042/bj3160373.

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The assembly process of the dipyrromethane cofactor of Escherichia coli porphobilinogen deaminase holoenzyme is initiated by the reaction of the porphobilinogen deaminase apoenzyme with preuroporphyrinogen. The resulting enzyme-bound tetrapyrrole (bilane) is equivalent to the holoenzyme intermediate complex ES2 and yields the dipyrromethane cofactor by reactions of the normal catalytic cycle. These observations indicate that preuroporphyrinogen, rather than porphobilinogen, is the preferred precursor for the dipyrromethane cofactor and explain the existence of the D84A and D84N deaminase mutants as catalytically inactive ES2 complexes.

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7

Jordan, P. M., e P. N. Gibbs. "Mechanism of action of 5-aminolaevulinate dehydratase from human erythrocytes". Biochemical Journal 227, n. 3 (1 maggio 1985): 1015–20. http://dx.doi.org/10.1042/bj2271015.

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Purified 5-aminolaevulinate dehydratase (porphobilinogen synthase, EC 4.2.1.24) from human erythrocytes was incubated initially with limiting amounts of 5-amino [5-14C]laevulinate in a rapid-mixing apparatus. The single-turnover reaction with respect to the bound labelled 5-aminolaevulinate was completed by the addition of unlabelled 5-aminolaevulinate and the resulting radioactive porphobilinogen was isolated and degraded. The 14C label was found to be located predominantly at C-2 of the product, demonstrating that, of the two substrate molecules participating in the reaction, the 5-aminolaevulinate molecule initially bound to the enzyme provides the propionic acid ‘side’ of the porphobilinogen. The same enzyme-[14C]substrate species that yields regiospecific porphobilinogen may be trapped by reaction with NaBH4, showing that the substrate molecule initially bound to the enzyme does so in the form of a Schiff base. A conventional incubation with 5-amino[5-14C]laevulinate yielded porphobilinogen with an equal distribution of the label between C-2 and C-11. The reaction mechanism of the human erythrocyte 5-aminolaevulinate dehydratase thus follows the same course as that of other dehydratases studied in our laboratory by using single-turnover techniques.

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8

Hsiao, Kwang-Jen, Fa-Yauh Lee, Shew-Jen Wu e Wei-Jan Chang. "Determination of erythrocyte porphobilinogen deaminase activity using porphobilinogen as substrate". Clinica Chimica Acta 168, n. 2 (settembre 1987): 257–58. http://dx.doi.org/10.1016/0009-8981(87)90296-8.

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9

Hart, G. J., C. Abell e A. R. Battersby. "Purification, N-terminal amino acid sequence and properties of hydroxymethylbilane synthase (porphobilinogen deaminase) from Escherichia coli". Biochemical Journal 240, n. 1 (15 novembre 1986): 273–76. http://dx.doi.org/10.1042/bj2400273.

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Hydroxymethylbilane synthase (porphobilinogen deaminase) was purified to apparent homogeneity from Escherichia coli. The enzyme is a monomer of Mr approx. 40,000. The Km for porphobilinogen and relative Vmax. values have been obtained at various pH values over the range 6.2-8.8, enabling pK values for ionizable groups important for activity to be determined. The N-terminal amino acid sequence is presented.

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10

Heinemann, Ilka U., Claudia Schulz, Wolf-Dieter Schubert, Dirk W. Heinz, Yang-G. Wang, Yuichi Kobayashi, Yuuki Awa, Masaaki Wachi, Dieter Jahn e Martina Jahn. "Structure of the Heme Biosynthetic Pseudomonas aeruginosa Porphobilinogen Synthase in Complex with the Antibiotic Alaremycin". Antimicrobial Agents and Chemotherapy 54, n. 1 (12 ottobre 2009): 267–72. http://dx.doi.org/10.1128/aac.00553-09.

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ABSTRACT The recently discovered antibacterial compound alaremycin, produced by Streptomyces sp. A012304, structurally closely resembles 5-aminolevulinic acid, the substrate of porphobilinogen synthase. During the initial steps of heme biosynthesis, two molecules of 5-aminolevulinic acid are asymmetrically condensed to porphobilinogen. Alaremycin was found to efficiently inhibit the growth of both Gram-negative and Gram-positive bacteria. Using the newly created heme-permeable strain Escherichia coli CSA1, we are able to uncouple heme biosynthesis from bacterial growth and demonstrate that alaremycin targets the heme biosynthetic pathway. Further studies focused on the activity of alaremycin against the opportunistic pathogenic bacterium Pseudomonas aeruginosa. The MIC of alaremycin was determined to be 12 mM. Alaremycin was identified as a direct inhibitor of recombinant purified P. aeruginosa porphobilinogen synthase and had a Ki of 1.33 mM. To understand the molecular basis of alaremycin's antibiotic activity at the atomic level, the P. aeruginosa porphobilinogen synthase was cocrystallized with the alaremycin. At 1.75-Å resolution, the crystal structure reveals that the antibiotic efficiently blocks the active site of porphobilinogen synthase. The antibiotic binds as a reduced derivative of 5-acetamido-4-oxo-5-hexenoic acid. The corresponding methyl group is, however, not coordinated by any amino acid residues of the active site, excluding its functional relevance for alaremycin inhibition. Alaremycin is covalently bound by the catalytically important active-site lysine residue 260 and is tightly coordinated by several active-site amino acids. Our data provide a solid structural basis to further improve the activity of alaremycin for rational drug design. Potential approaches are discussed.

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11

Fontanellas, A., J. A. Herrero, F. Coronel, J. L. Santos, M. J. Morán, A. Barrientos e R. Enríquez de Salamanca. "Effects of recombinant human erythropoietin on porphyrin metabolism in uremic patients on hemodialysis." Journal of the American Society of Nephrology 7, n. 5 (maggio 1996): 774–79. http://dx.doi.org/10.1681/asn.v75774.

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Recombinant human erythropoietin (r-HuEPO) is being successfully used for the treatment of uremic anemia. Several abnormalities of heme biosynthetic pathway have been described in patients with end-stage renal failure. In this condition, the activity of erythrocyte porphobilinogen deaminase has been found to be slightly increased. If this enzyme were to be the key enzyme in erythroid heme regulation, its activity would be increased to an even greater degree during the correction of uremic anemia. To assess this hypothesis, this study followed the variations of this and other parameters of porphyrin metabolism over 12 months of erythropoietin therapy in eight patients with nephrogenic anemia who underwent hemodialysis. By the first month of therapy, an increase of the previously depressed erythrocyte activity of aminolevulinate dehydratase was already evident, in coincidence with a nonsignificant increase of the reticulocyte count. The activity of this enzyme reached its maximal level by Month 3, and did not change up to Month 10. The porphobilinogen deaminase hyperactivity normalized at Month 4. By Month 12, in coincidence with the reduction of erythropoietin doses, the maximal levels of erythrocyte protoporphyrin, and the decrease in aminolevulinate dehydratase activity, the porphobilinogen deaminase values started to increase once again. In conclusion, the administration of r-HuEPO to hemodialyzed patients induced transient normalization of the previously observed porphyrin metabolism abnormalities. However, erythrocyte porphobilinogen deaminase activity did not rise concomitantly with the increase in hematocrit or hemoglobin values, but it did diminish during treatment. Therefore, porphobilinogen deaminase did not behave as a controlling enzyme in heme synthesis during the r-HuEPO-induced correction of uremic anemia.

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12

Rossetti, M. V., A. A. Juknat e A. M. del C. Batlle. "Soluble and Particulate Porphobilinogen-Deaminase from Dark-Grown Euglena gracilis". Zeitschrift für Naturforschung C 44, n. 7-8 (1 agosto 1989): 578–80. http://dx.doi.org/10.1515/znc-1989-7-807.

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A highly efficient method employing NaSCN as a chaotropic agent was used to dissociate the membrane-bound porphobilinogen-deaminase. The same sequence of steps was applied for purifying both soluble and membrane dissociated porphobilinogen-deam inase. The chromatographic behaviour of both proteins was quite similar. Euglena gracilis deam inase appears to exist in an equilibrium mixture of two active species of relative molecular masses of 40000 and 20000.

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13

Biel, Alan J., Keith Canada, David Huang, Karl Indest e Karen Sullivan. "Oxygen-Mediated Regulation of Porphobilinogen Formation in Rhodobacter capsulatus". Journal of Bacteriology 184, n. 6 (15 marzo 2002): 1685–92. http://dx.doi.org/10.1128/jb.184.6.1685-1692.2002.

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ABSTRACT A Rhodobacter capsulatus hemC mutant has been isolated and used to show that oxygen regulates the intracellular levels of porphobilinogen. Experiments using a hemB-cat gene fusion demonstrated that oxygen does not transcriptionally regulate hemB transcription. Porphobilinogen synthase activity is not regulated by oxygen nor is the enzyme feedback inhibited by hemin or protoporphyrin IX. It was demonstrated that less than 20% of [14C]aminolevulinate was incorporated into bacteriochlorophyll, suggesting that the majority of the aminolevulinate is diverted from the common tetrapyrrole pathway. Porphobilinogen oxygenase activity was not observed in this organism; however, an NADPH-linked aminolevulinate dehydrogenase activity was demonstrated. The specific activity of this enzyme increased with increasing oxygen tension. The results presented here suggest that carbon flow over the common tetrapyrrole pathway is regulated by a combination of feedback inhibition of aminolevulinate synthase and diversion of aminolevulinate from the pathway by aminolevulinate dehydrogenase.

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14

Shimoni-Livny, L., H. L. Carrell, T. Wagner, A. Kaufman Katz, C. Afshar, L. W. Mitchell, M. Volin, E. K. Jaffe e J. P. Glusker. "Crystallization and preliminary X-ray diffraction studies of E. coli porphobilinogen synthase and its heavy-atom derivatives". Acta Crystallographica Section D Biological Crystallography 54, n. 3 (1 maggio 1998): 438–40. http://dx.doi.org/10.1107/s0907444997010925.

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Porphobilinogen synthase (PBGS) catalyzes the condensation of two identical substrate molecules, 5-aminolevulinic acid (ALA), in an asymmetric manner to form porphobilinogen. E. coli PBGS is an homooctameric enzyme. The number of active sites is not clear, but each subunit binds one ZnII ion and one MgII ion. Diffraction-quality crystals of native E. coli PBGS have been obtained, and unit-cell dimensions (a = 130.8, c = 144.0 Å) are reported. These crystals diffract to about 3.0 Å resolution.

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15

Cheung, Kwai-Ming, e Peter M. Shoolingin-Jordan. "Facile Chemical Syntheses of Porphobilinogen Analogues: A Four-Step Synthesis of iso-Porphobilinogen". Synthesis 2001, n. 11 (2001): 1627–30. http://dx.doi.org/10.1055/s-2001-16752.

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16

García, Susana Raquel Correa, Maria Victoria Rossetti e Alcira María del Carmen Batlle. "Studies on Porphobilinogen-Deaminase from Saccharomyces cerevisiae". Zeitschrift für Naturforschung C 46, n. 11-12 (1 dicembre 1991): 1017–23. http://dx.doi.org/10.1515/znc-1991-11-1215.

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Abstract Porphobilinogen-deaminase from Saccharomyces cerevisiae has been isolated and partially purified 80-and 230-fold in the absence or presence of phenylmethylsulphonyl fluoride, respectively.Some properties of the isolated enzyme were studied. Porphyrin formation was linear with time and protein concentration. Optimum pH was about 7.5-7.8. Molecular mass of the protein was 30,000 ± 3000 Dalton when the enzyme was purified in the presence of phenylmethyl sulphonyl fluoride. A less active and unstable 20,000 Da molecular mass species was obtained when purification was performed in the absence of the protease inhibitor.Porphobilinogen-deaminase exhibited classical Michaelis-Menten kinetics. The apparent Km for uroporphyrinogen formation was 19 μм; Vmax was 3.6 nmol uroporphyrin/h and the Hill coefficient was n = 1.Also the action of several reagents on the activity was studied. Protective thiol agents had no effect. Heavy metals inhibited both porphyrin formation and porphobilinogen consumption, but known sulphydryl inactivating chemicals inhibit the former without modifying the latter. Ammonium ions had no effect on the activity while hydroxylamine completely inhibited both porphyrin formation and porphobilinogen consumption.

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17

Woolf, Jacqueline, Joanne T. Marsden, Timothy Degg, Sharon Whatley, Paul Reed, Nadia Brazil, M. Felicity Stewart e Michael Badminton. "Best practice guidelines on first-line laboratory testing for porphyria". Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 54, n. 2 (19 gennaio 2017): 188–98. http://dx.doi.org/10.1177/0004563216667965.

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The porphyrias are disorders of haem biosynthesis which present with acute neurovisceral attacks or disorders of sun-exposed skin. Acute attacks occur mainly in adults and comprise severe abdominal pain, nausea, vomiting, autonomic disturbance, central nervous system involvement and peripheral motor neuropathy. Cutaneous porphyrias can be acute or chronic presenting at various ages. Timely diagnosis depends on clinical suspicion leading to referral of appropriate samples for screening by reliable biochemical methods. All samples should be protected from light. Investigation for an acute attack: • Porphobilinogen (PBG) quantitation in a random urine sample collected during symptoms. Urine concentration must be assessed by measuring creatinine, and a repeat requested if urine creatinine <2 mmol/L. • Urgent porphobilinogen testing should be available within 24 h of sample receipt at the local laboratory. Urine porphyrin excretion (TUP) should subsequently be measured on this urine. • Urine porphobilinogen should be measured using a validated quantitative ion-exchange resin-based method or LC-MS. • Increased urine porphobilinogen excretion requires confirmatory testing and clinical advice from the National Acute Porphyria Service. • Identification of individual acute porphyrias requires analysis of urine, plasma and faecal porphyrins. Investigation for cutaneous porphyria: • An EDTA blood sample for plasma porphyrin fluorescence emission spectroscopy and random urine sample for TUP. • Whole blood for porphyrin analysis is essential to identify protoporphyria. • Faeces need only be collected, if first-line tests are positive or if clinical symptoms persist. Investigation for latent porphyria or family history: • Contact a specialist porphyria laboratory for advice. Clinical, family details are usually required.

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18

Leeper, Finian J., Martin Rock e Diana Appleton. "Synthesis of analogues of porphobilinogen". Journal of the Chemical Society, Perkin Transactions 1, n. 21 (1996): 2633. http://dx.doi.org/10.1039/p19960002633.

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19

Gorchein, Abel. "Testing for Porphobilinogen in Urine". Clinical Chemistry 48, n. 3 (1 marzo 2002): 564–66. http://dx.doi.org/10.1093/clinchem/48.3.564.

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20

Beaumont, C., C. Porcher, C. Picat, Y. Nordmann e B. Grandchamp. "The Mouse Porphobilinogen Deaminase Gene". Journal of Biological Chemistry 264, n. 25 (settembre 1989): 14829–34. http://dx.doi.org/10.1016/s0021-9258(18)63775-5.

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21

Noriega, Guillermo, Guillermo Mattei, Alcira Batlle e Adela Ana Juknat. "Rat kidney porphobilinogen deaminase kinetics". International Journal of Biochemistry & Cell Biology 34, n. 10 (ottobre 2002): 1230–40. http://dx.doi.org/10.1016/s1357-2725(02)00051-1.

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22

Umanoff, H., C. S. Russell e S. D. Cosloy. "Availability of porphobilinogen controls appearance of porphobilinogen deaminase activity in Escherichia coli K-12." Journal of Bacteriology 170, n. 10 (1988): 4969–71. http://dx.doi.org/10.1128/jb.170.10.4969-4971.1988.

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23

Leeper, Finian J., e Martin Rock. "Modified substrates for tetrapyrrole biosynthesis: analogues of porphobilinogen showing unusual inhibition of porphobilinogen deaminase". Journal of the Chemical Society, Chemical Communications, n. 3 (1992): 242. http://dx.doi.org/10.1039/c39920000242.

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24

Kondo, M., e G. Urata. "Radiochemical microassay of delta-aminolevulinic acid dehydratase activity in whole blood and bone marrow." Clinical Chemistry 31, n. 3 (1 marzo 1985): 427–29. http://dx.doi.org/10.1093/clinchem/31.3.427.

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Abstract We describe an assay for delta-aminolevulinic acid dehydratase (EC 4.2.1.24) activity. Radioactive [14C]porphobilinogen, formed by action of this enzyme on [14C]delta-aminolevulinic acid, is purified by passage through an ion-exchange chromatographic column before measurement with a liquid scintillation counter. The radioactive substance in the final solution was identified as solely [14C]porphobilinogen by paper-chromatographic analysis. The present assay procedure requires only a 0.1-microL sample of blood and is about 100-fold more sensitive than the conventional colorimetric methods involving Ehrlich's reagent. Using this method, we found that activity of this enzyme in the bone marrow of rats decreases abruptly and sharply two weeks after birth.

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25

Jordan, P. M., S. D. Thomas e M. J. Warren. "Purification, crystallization and properties of porphobilinogen deaminase from a recombinant strain of Escherichia coli K12". Biochemical Journal 254, n. 2 (1 settembre 1988): 427–35. http://dx.doi.org/10.1042/bj2540427.

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Porphobilinogen deaminase has been purified and crystallized from an overproducing recombinant strain of Escherichia coli harbouring a hemC-containing plasmid which has permitted the purification of milligram quantities of the enzyme. Determination of the Mr of the enzyme by SDS/polyacrylamide-gel electrophoresis (35,000) and gel filtration (32,000) agrees with the gene-derived Mr of 33,857. The enzyme has a Km of 19 +/- 7 microM, an isoelectric point of 4.5 and an N-terminal sequence NH2-MLDNVLRIAT. The substrate, porphobilinogen, binds to the active-site dipyrromethane cofactor to form three intermediate complexes: ES, ES2 and ES3. The gene-derived primary structure of the E. coli deaminase is compared with that derived from the cDNA of the human enzyme.

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26

Kotler, ML, AA Juknat, SA Fumagalli e AM Batlle. "Involvement of free and enzyme‐bound intermediates in the reaction mechanism catalyzed by the bovine liver immobilized porphobilinogen deaminase. Proof that they are substrates for cosynthetase in uroporphyrinogen III biosynthesis". Biotechnology and Applied Biochemistry 13, n. 2 (aprile 1991): 173–80. http://dx.doi.org/10.1111/j.1470-8744.1991.tb00150.x.

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The detection and accumulation of tetrapyrrole intermediates synthesized by the action of bovine liver porphobilinogen deaminase immobilized to Sepharose 4B is reported. Employing Sepharose‐deaminase preparations, two phases in uroporphyrinogen I synthesis as a function of time were observed, suggesting the accumulation of free and enzyme‐bound intermediates, the concentration and distribution of which were time dependent. The deaminase‐bound intermediate behaves as a substrate in uroporphyrinogen I synthesis whereas the free intermediates produce enzyme inhibition. The tetrapyrrole intermediate bound to the Sepharose‐enzyme is removed from the protein by the binding of porphobilinogen. Free as well as enzyme‐bound intermediates are shown to be substrates for cosynthetase with formation of 80% uroporphyrinogen III.

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27

Pichon, Clotilde, Karen R. Clemens, Alan R. Jacobson e A. Ian Scott. "On the mechanism of porphobilinogen deaminase. Design, synthesis, and enzymatic reactions of novel porphobilinogen analogs." Tetrahedron 48, n. 23 (giugno 1992): 4687–712. http://dx.doi.org/10.1016/s0040-4020(01)81567-2.

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28

Cheung, Kwai-Ming, e Peter M. Shoolingin-Jordan. "ChemInform Abstract: Facile Chemical Syntheses of Porphobilinogen Analogues: A Four-Step Synthesis to iso-Porphobilinogen." ChemInform 32, n. 51 (23 maggio 2010): no. http://dx.doi.org/10.1002/chin.200151130.

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Lawrence, Sarah H., Ursula D. Ramirez, Trevor Selwood, Linda Stith e Eileen K. Jaffe. "Allosteric Inhibition of Human Porphobilinogen Synthase". Journal of Biological Chemistry 284, n. 51 (7 ottobre 2009): 35807–17. http://dx.doi.org/10.1074/jbc.m109.026294.

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30

Jamani, A., M. Pudek e W. E. Schreiber. "Liquid-chromatographic assay of urinary porphobilinogen." Clinical Chemistry 35, n. 3 (1 marzo 1989): 471–75. http://dx.doi.org/10.1093/clinchem/35.3.471.

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Abstract This is a rapid (10 min per sample), highly sensitive procedure for quantifying urinary porphobilinogen (PBG). Interfering substances are removed by selectively adsorbing PBG onto an ion-exchange resin. After PBG is eluted with 0.5 mol/L formic acid, Ehrlich's reagent is added to produce the chromophore, which is then injected into a liquid chromatograph equipped with a diode-array detector. PBG is separated by a linear gradient (10% to 100%) of methanol in 10 mmol/L phosphate buffer, pH 3.0. Absorbance is monitored at 555 nm. Assay response varies linearly with PBG concentration over the range 0-110 mumol/L (0-25 mg/L). As little as 1.5 mumol/L (0.3 mg/L) can be detected. In prepared urine samples with known PBG concentrations, the within-run coefficient of variation (CV) ranged from 1.7% to 3.2%, the day-to-day CV from 3.5% to 6.1%. PBG concentrations in 24-h urine collected from 25 healthy subjects were all below the detection limit of the assay (less than 1.5 mumol/L). We used the new assay to measure PBG concentrations in the urine of two patients with latent porphyria. This method is more sensitive than spectrophotometric techniques currently used for measuring urinary PBG.

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Rietschel, M., M. Nöthen, J. Körner, M. Lanczik, J. Erdmann, S. Cichon, H. J. Möller e P. Propping. "PORPHOBILINOGEN DEAMINASE GENE ALLELES IN SCHIZOPHRENIA". Clinical Neuropharmacology 15 (1992): 301B. http://dx.doi.org/10.1097/00002826-199202001-00582.

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32

McNeill, Luke A., e Peter M. Shoolingin-Jordan. "Dipyrromethane cofactor assembly in porphobilinogen deaminase". Biochemical Society Transactions 26, n. 3 (1 agosto 1998): S286. http://dx.doi.org/10.1042/bst026s286.

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33

Jaffe, Eileen K. "The porphobilinogen synthase family of metalloenzymes". Acta Crystallographica Section D Biological Crystallography 56, n. 2 (1 febbraio 2000): 115–28. http://dx.doi.org/10.1107/s0907444999014894.

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Jaffe, Eileen K. "The Remarkable Character of Porphobilinogen Synthase". Accounts of Chemical Research 49, n. 11 (26 ottobre 2016): 2509–17. http://dx.doi.org/10.1021/acs.accounts.6b00414.

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35

Clemens, Karen R., Clotilde Pichon, Alan R. Jacobson, Paul Yon-Hin, Mario D. Gonzalez e A. Ian Scott. "Systematic specificity studies on porphobilinogen deaminase". Bioorganic & Medicinal Chemistry Letters 4, n. 3 (febbraio 1994): 521–24. http://dx.doi.org/10.1016/0960-894x(94)80029-4.

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36

Jaffe, Eileen K. "The porphobilinogen synthase catalyzed reaction mechanism". Bioorganic Chemistry 32, n. 5 (ottobre 2004): 316–25. http://dx.doi.org/10.1016/j.bioorg.2004.05.010.

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37

Buttery, Joseph E., Anna-Maria Carrera e Peter R. Pannall. "Reliability of the porphobilinogen screening assay". Pathology 22, n. 4 (1990): 197–98. http://dx.doi.org/10.3109/00313029009086660.

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38

Shanmugam, Dhanasekaran, Bo Wu, Ursula Ramirez, Eileen K. Jaffe e David S. Roos. "Plastid-associated Porphobilinogen Synthase fromToxoplasma gondii". Journal of Biological Chemistry 285, n. 29 (4 maggio 2010): 22122–31. http://dx.doi.org/10.1074/jbc.m110.107243.

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39

Bung, Navneet, Arijit Roy, U. Deva Priyakumar e Gopalakrishnan Bulusu. "Computational modeling of the catalytic mechanism of hydroxymethylbilane synthase". Physical Chemistry Chemical Physics 21, n. 15 (2019): 7932–40. http://dx.doi.org/10.1039/c9cp00196d.

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Abstract (sommario):

Hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthesis pathway, catalyzes the formation of 1-hydroxymethylbilane (HMB) by a stepwise polymerization of four molecules of porphobilinogen (PBG) using the dipyrromethane (DPM) cofactor.

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40

Kaur, Tanpreet, Preeti Wadhwa e Anuj Sharma. "Arylsulfonylmethyl isocyanides: a novel paradigm in organic synthesis". RSC Advances 5, n. 65 (2015): 52769–87. http://dx.doi.org/10.1039/c5ra07876h.

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Abstract (sommario):

p-Tosylmethyl isocyanide (TosMIC), an α-acidic isocyanide has emerged as a privileged reagent to access biologically relevant fused heterocycles and some natural products like (−)-ushikulide A, variolin B, porphobilinogen and mansouramycin B.

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41

Helliwell, John R. "The crystal structures of the enzyme hydroxymethylbilane synthase, also known as porphobilinogen deaminase". Acta Crystallographica Section F Structural Biology Communications 77, n. 11 (19 ottobre 2021): 388–98. http://dx.doi.org/10.1107/s2053230x2100964x.

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The enzyme hydroxymethylbilane synthase (HMBS; EC 4.3.1.8), also known as porphobilinogen deaminase, catalyses the stepwise addition of four molecules of porphobilinogen to form the linear tetrapyrrole 1-hydroxymethylbilane. Thirty years of crystal structures are surveyed in this topical review. These crystal structures aim at the elucidation of the structural basis of the complex reaction mechanism involving the formation of tetrapyrrole from individual porphobilinogen units. The consistency between the various structures is assessed. This includes an evaluation of the precision of each molecular model and what was not modelled. A survey is also made of the crystallization conditions used in the context of the operational pH of the enzyme. The combination of 3D structural techniques, seeking accuracy, has also been a feature of this research effort. Thus, SAXS, NMR and computational molecular dynamics have also been applied. The general framework is also a considerable chemistry research effort to understand the function of the enzyme and its medical pathologies in acute intermittent porphyria (AIP). Mutational studies and their impact on the catalytic reaction provide insight into the basis of AIP and are also invaluable for guiding the understanding of the crystal structure results. Future directions for research on HMBS are described, including the need to determine the protonation states of key amino-acid residues identified as being catalytically important. The question remains – what is the molecular engine for this complex reaction? Thermal fluctuations are the only suggestion thus far.

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42

Wei, Ho-Chun, Huidy Shu e James V. Price. "Functional genomic analysis of the 61D-61F region of the third chromosome of Drosophila melanogaster". Genome 46, n. 6 (1 dicembre 2003): 1049–58. http://dx.doi.org/10.1139/g03-081.

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Assigning functional significance to completed genome sequences is one of the next challenges in biological science. Conventional genetic tools such as deficiency chromosomes help assign essential complementation groups to their corresponding genes. We describe an F2 genetic screen to identify lethal mutations within cytogenetic region 61D-61F of the third chromosome of Drosophila melanogaster. One hundred sixteen mutations were identified by their failure to complement both Df(3L)bab-PG and Df(3L)3C7. These alleles were assigned to 14 complementation groups and 9 deficiency intervals. Complementation groups were ordered using existing deficiencies, as well as new deficiencies generated in this study. With the aid of the genomic sequence, genetic and physical maps in the region were correlated by use of PCR to localize the breakpoints of deficiencies within a 268-kb genomic contig (GenBank accession No. AC005847). Six essential complementation groups were assigned to specific genes, including genes encoding a porphobilinogen deaminase and a Sac1-like protein.Key words: Drosophila, functional genomics, porphobilinogen deaminase, synaptojanin.

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43

Luo, J., e C. K. Lim. "Order of uroporphyrinogen III decarboxylation on incubation of porphobilinogen and uroporphyrinogen III with erythrocyte uroporphyrinogen decarboxylase". Biochemical Journal 289, n. 2 (15 gennaio 1993): 529–32. http://dx.doi.org/10.1042/bj2890529.

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The isomeric compositions of the heptacarboxylic, hexacarboxylic and pentacarboxylic porphyrinogens formed by incubation of porphobilinogen with human red-cell haemolysates have been analysed and compared with those derived from incubation with chemically prepared uroporphyrinogen III as substrate. The results indicated that when supplied with an excess (3.7 microM) of exogenous uroporphyrinogen III, uroporphyrinogen decarboxylase utilized the substrate at random and a mixture of isomers was produced; whereas with uroporphyrinogen III generated enzymically from porphobilinogen as substrate a clockwise decarboxylation sequence was observed, resulting in the formation of intermediates mainly with the ring-D, rings-AD and rings-ABD acetate groups decarboxylated. Using [14C]uroporphyrinogen III as substrate at low concentrations (0.01-0.5 microM) also led to preferential decarboxylation of the ring-D acetate group. It was concluded that the order of uroporphyrinogen III decarboxylation is substrate-concentration-dependent, and under normal physiological conditions enzymic decarboxylation is most probably orderly and clockwise, starting at the ring-D acetate group.

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44

Scott, A. I., N. J. Stolowich, H. J. Williams, M. D. Gonzalez, C. A. Roessner, S. K. Grant e C. Pichon. "Concerning the catalytic site of porphobilinogen deaminase". Journal of the American Chemical Society 110, n. 17 (agosto 1988): 5898–900. http://dx.doi.org/10.1021/ja00225a051.

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45

Deybach, Jean Charles, e Hervé Puy. "Porphobilinogen deaminase gene structure and molecular defects". Journal of Bioenergetics and Biomembranes 27, n. 2 (aprile 1995): 197–205. http://dx.doi.org/10.1007/bf02110034.

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46

Mazzetti, Marta B., e J. Maria Tomio. "Characterization of porphobilinogen deaminase from rat liver". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 957, n. 1 (novembre 1988): 97–104. http://dx.doi.org/10.1016/0167-4838(88)90161-6.

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47

Ostrowski, Jerzy. "Erythrocyte Porphobilinogen Deaminase Activity in Lives Disease". Gastroenterology 92, n. 4 (aprile 1987): 845–51. http://dx.doi.org/10.1016/0016-5085(87)90956-5.

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48

LEEPER, F. J., M. ROCK e D. APPLETON. "ChemInform Abstract: Synthesis of Analogues of Porphobilinogen." ChemInform 28, n. 34 (3 agosto 2010): no. http://dx.doi.org/10.1002/chin.199734233.

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49

Evans, J. N. S., P. E. Fagerness, N. E. Mackenzie e A. I. Scott. "1H,3H and13C NMR studies on porphobilinogen". Magnetic Resonance in Chemistry 23, n. 11 (novembre 1985): 939–44. http://dx.doi.org/10.1002/mrc.1260231112.

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50

Adamczyk, Maciej, e Rajarathnam E. Reddy. "A convenient and versatile synthesis of porphobilinogen". Tetrahedron Letters 36, n. 50 (dicembre 1995): 9121–24. http://dx.doi.org/10.1016/0040-4039(95)01979-r.

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