1
|
Suárez L, Kosar AJ, Dodd EL, Tazoo D, Lambert AC, Bohle DS. Soluble meso and deuteroporphyrin analogs of the malaria pigment hematin anhydride. J Inorg Biochem 2024; 252:112470. [PMID: 38218137 DOI: 10.1016/j.jinorgbio.2023.112470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 01/15/2024]
Abstract
Two soluble heme analogs of the insoluble malaria pigment hematin anhydride (HA, or β-hematin), [Fe(III)(protoporphyrin)]2, with either mesoporphyrin (MHA) or deuteroporphyrin (DHA) are characterized by elemental analysis, SEM, IR spectroscopy, electronic spectroscopy, paramagnetic 1H NMR spectroscopy and solution magnetic susceptibility. While prior single crystal and X-ray powder diffraction results indicate all three have a common propionate linked dimer motif, there is considerable solid state variation in the conformation. This is associated with enhanced solubility of MHA and DHA. As with HA, DHA undergoes thermally promoted reversible hydration/dehydration in the solid state. Solution 1H NMR studies of DHA suggest a high spin dimeric structure with the porphyrin methyls distributed between two isomers which are also present in the solid state. These soluble iron(III)porphyrin dimers allow for the first direct solution studies by NMR and UV-Vis spectroscopies of these key species. Taken together the results illustrate the importance and utility of varying the substituents on the periphery of the porphyrin for studying heme aggregation and malaria pigment formation.
Collapse
Affiliation(s)
- Liliana Suárez
- Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal H3A 0B8, Canada
| | - Aaron J Kosar
- Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal H3A 0B8, Canada
| | - Erin L Dodd
- Département de Chimie de l'UQAM, 2101, rue Jeanne-Mance, Montréal H2X 2J6, Canada
| | - Dagobert Tazoo
- Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal H3A 0B8, Canada
| | | | - D Scott Bohle
- Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal H3A 0B8, Canada.
| |
Collapse
|
2
|
Wolf S, Domes R, Domes C, Frosch T. Spectrally Resolved and Highly Parallelized Raman Difference Spectroscopy for the Analysis of Drug-Target Interactions between the Antimalarial Drug Chloroquine and Hematin. Anal Chem 2024; 96:3345-3353. [PMID: 38301154 PMCID: PMC10902819 DOI: 10.1021/acs.analchem.3c04231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Malaria is a severe disease caused by cytozoic parasites of the genus Plasmodium, which infiltrate and infect red blood cells. Several drugs have been developed to combat the devastating effects of malaria. Antimalarials based on quinolines inhibit the crystallization of hematin into hemozoin within the parasite, ultimately leading to its demise. Despite the frequent use of these agents, there are unanswered questions about their mechanisms of action. In the present study, the quinoline chloroquine and its interaction with the target structure hematin was investigated using an advanced, highly parallelized Raman difference spectroscopy (RDS) setup. Simultaneous recording of the spectra of hematin and chloroquine mixtures with varying compositions enabled the observation of changes in peak heights and positions based on the altered molecular structure resulting from their interaction. A shift of (-1.12 ± 0.05) cm-1 was observed in the core-size marker band ν(CαCm)asym peak position of the 1:1 chloroquine-hematin mixture compared to pure hematin. The oxidation-state marker band ν(pyrrole half-ring)sym exhibited a shift by (+0.93 ± 0.13) cm-1. These results were supported by density functional theory (DFT) calculations, indicating a hydrogen bond between the quinolinyl moiety of chloroquine and the oxygen atom of ferric protoporphyrin IX hydroxide (Fe(III)PPIX-OH). The consequence is a reduced electron density within the porphyrin moiety and an increase in its core size. This hypothesis provided further insights into the mechanism of hemozoin inhibition, suggesting chloroquine binding to the monomeric form of hematin, thereby preventing its further crystallization to hemozoin.
Collapse
Affiliation(s)
- Sebastian Wolf
- Leibniz Institute of Photonic Technology, 07745 Jena, Germany
| | - Robert Domes
- Leibniz Institute of Photonic Technology, 07745 Jena, Germany
| | - Christian Domes
- Leibniz Institute of Photonic Technology, 07745 Jena, Germany
| | - Torsten Frosch
- Biophotonics and Biomedical Engineering Group, Technical University Darmstadt, Merckstr. 25, 64283 Darmstadt, Germany
- Leibniz Institute of Photonic Technology, 07745 Jena, Germany
| |
Collapse
|
3
|
Rossier J, Nasiri Sovari S, Pavic A, Vojnovic S, Stringer T, Bättig S, Smith GS, Nikodinovic-Runic J, Zobi F. Antiplasmodial Activity and In Vivo Bio-Distribution of Chloroquine Molecules Released with a 4-(4-Ethynylphenyl)-Triazole Moiety from Organometallo-Cobalamins. Molecules 2019; 24:molecules24122310. [PMID: 31234469 PMCID: PMC6630517 DOI: 10.3390/molecules24122310] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 01/01/2023] Open
Abstract
We have explored the possibility of using organometallic derivatives of cobalamin as a scaffold for the delivery of the same antimalarial drug to both erythro- and hepatocytes. This hybrid molecule approach, intended as a possible tool for the development of multi-stage antimalarial agents, pivots on the preparation of azide-functionalized drugs which, after coupling to the vitamin, are released with a 4-(4-ethynylphenyl)-triazole functionality. Three chloroquine and one imidazolopiperazine derivative (based on the KAF156 structure) were selected as model drugs. One hybrid chloroquine conjugate was extensively studied via fluorescent labelling for in vitro and in vivo bio-distribution studies and gave proof-of-concept for the design. It showed no toxicity in vivo (zebrafish model) as well as no hepatotoxicity, no cardiotoxicity or developmental toxicity of the embryos. All 4-(4-ethynylphenyl)-triazole derivatives of chloroquine were equally active against chloroquine-resistant (CQR) and chloroquine-sensitive (CQS) Plasmodium falciparum strains.
Collapse
Affiliation(s)
- Jeremie Rossier
- Department of Chemistry, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| | - Sara Nasiri Sovari
- Department of Chemistry, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| | - Aleksandar Pavic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11000 Belgrade, Republic of Serbia.
| | - Sandra Vojnovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11000 Belgrade, Republic of Serbia.
| | - Tameryn Stringer
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.
| | - Sarah Bättig
- Department of Chemistry, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| | - Gregory S Smith
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.
| | - Jasmina Nikodinovic-Runic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11000 Belgrade, Republic of Serbia.
| | - Fabio Zobi
- Department of Chemistry, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| |
Collapse
|
4
|
Nath A, Dharmadhikari JA, Dharmadhikari AK, Mathur D, Mazumdar S. Ultrafast dynamics of hemin aggregates. Phys Chem Chem Phys 2017; 19:26862-26869. [PMID: 28952613 DOI: 10.1039/c7cp04858k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effects of solvents on the conformation of hemin and their implications on the dynamics of the complex have been studied using the time-resolved optical Kerr effect (OKE) with 35 fs laser pulses (at a central wavelength of 800 nm). The OKE enabled estimation to be made of the third-order nonlinear electronic susceptibility (χ(3)) of hemin solutions: it was found to be significantly smaller than that in hemin thin films. The real and imaginary components of χ(3) were negative in both the solvents, suggesting that one-photon as well as two-photon absorption processes contribute to the nonlinear electronic susceptibility of hemin. Our study of the ultrafast heme dynamics not only unveils the instantaneous electronic response related to electronic susceptibility but also brings to the fore a novel libration process that has hitherto remained undetected. The hindered rotation in the femtosecond domain that may be responsible for this libration process possibly stems from π-π hemin oligomers formed in aqueous solution. The present results provide new insights into the conformational dynamics in the self-assembly of heme oligomers that may also be significant in certain pathogenic conditions where free heme is formed in biological systems.
Collapse
Affiliation(s)
- Arpita Nath
- Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Mumbai 400005, India.
| | | | | | | | | |
Collapse
|
5
|
Kuter D, Streltsov V, Davydova N, Venter GA, Naidoo KJ, Egan TJ. Molecular structures and solvation of free monomeric and dimeric ferriheme in aqueous solution: insights from molecular dynamics simulations and extended X-ray absorption fine structure spectroscopy. Inorg Chem 2014; 53:10811-24. [PMID: 25275882 DOI: 10.1021/ic500454d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CHARMM force field parameters have been developed to model nonprotein bound five-coordinate ferriheme (ferriprotoporphyrin IX) species in aqueous solution. Structures and solvation were determined from molecular dynamics (MD) simulations at 298 K of monomeric [HO-ferriheme](2-), [H2O-ferriheme](-), and [H2O-ferriheme](0); π-π dimeric [(HO-ferriheme)2](4-), [(H2O-ferriheme)(HO-ferriheme)](3-), [(H2O-ferriheme)2](2-), and [(H2O-ferriheme)2](0); and μ-oxo dimeric [μ-(ferriheme)2O](4-). Solvation of monomeric species predominated around the axial ligand, meso-hydrogen atoms of the porphyrin ring (Hmeso), and the unligated face. Existence of π-π ferriheme dimers in aqueous solution was supported by MD calculations where such dimers remained associated over the course of the simulation. Porphyrin rings were essentially coplanar. In these dimers major and minor solvation was observed around the axial ligand and Hmeso positions, respectively. In μ-oxo ferriheme, strong solvation of the unligated face and bridging oxide ligand was observed. The solution structure of the μ-oxo dimer was investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy. The EXAFS spectrum obtained from frozen solution was markedly different from that recorded on dried μ-oxo ferriheme solid. Inclusion of five solvent molecules obtained from spatial distribution functions in the structure generated from MD simulation was required to produce acceptable fits to the EXAFS spectra of the dimer in solution, while the solid was suitably fitted using the crystal structure of μ-oxo ferriheme dimethyl ester which included no solvent molecules.
Collapse
Affiliation(s)
- David Kuter
- Scientific Computing Research Unit, †Department of Chemistry, University of Cape Town , Private Bag, Rondebosch 7701, South Africa
| | | | | | | | | | | |
Collapse
|
6
|
Kuter D, Venter GA, Naidoo KJ, Egan TJ. Experimental and time-dependent density functional theory characterization of the UV-visible spectra of monomeric and μ-oxo dimeric ferriprotoporphyrin IX. Inorg Chem 2012; 51:10233-50. [PMID: 22963249 DOI: 10.1021/ic301154e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Speciation of ferriprotoporphyrin IX, Fe(III)PPIX, in aqueous solution is complex. Despite the use of its characteristic spectroscopic features for identification, the theoretical basis of the unique UV-visible absorbance spectrum of μ-[Fe(III)PPIX](2)O has not been explored. To investigate this and to establish a structural and spectroscopic model for Fe(III)PPIX species, density functional theory (DFT) calculations were undertaken for H(2)O-Fe(III)PPIX and μ-[Fe(III)PPIX](2)O. The models agreed with related Fe(III)porphyrin crystal structures and reproduced vibrational spectra well. The UV-visible absorbance spectra of H(2)O-Fe(III)PPIX and μ-[Fe(III)PPIX](2)O were calculated using time-dependent DFT and reproduced major features of the experimental spectra of both. Transitions contributing to calculated excitations have been identified. The features of the electronic spectrum calculated for μ-[Fe(III)PPIX](2)O were attributed to delocalization of electron density between the two porphyrin rings of the dimer, the weaker ligand field of the axial ligand, and antiferromagnetic coupling of the Fe(III) centers. Room temperature magnetic circular dichroism (MCD) spectra have been recorded and are shown to be useful in distinguishing between these two Fe(III)PPIX species. Bands underlying major spectroscopic features were identified through simultaneous deconvolution of UV-visible and MCD spectra. Computed UV-visible spectra were compared to deconvoluted spectra. Interpretation of the prominent bands of H(2)O-Fe(III)PPIX largely conforms to previous literature. Owing to the weak paramagnetism of μ-[Fe(III)PPIX](2)O at room temperature and the larger number of underlying excitations, interpretation of its experimental UV-visible spectrum was necessarily tentative. Nonetheless, comparison with the calculated spectra of antiferromagnetically coupled and paramagnetic forms of the μ-oxo dimer of Fe(III)porphine suggested that the composition of the Soret band involves a mixture of π→π* and π→d(π) charge transfer transitions. The Q-band and charge transfer bands appear to amalgamate into a mixed low energy envelope consisting of excitations with heavily admixed π→π* and charge transfer transitions.
Collapse
Affiliation(s)
- David Kuter
- Department of Chemistry, Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701 South Africa
| | | | | | | |
Collapse
|
7
|
Interaction of quinoline antimalarial drugs with ferriprotoporphyrin IX, a solid state spectroscopy study. J Inorg Biochem 2011; 105:1662-9. [DOI: 10.1016/j.jinorgbio.2011.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/05/2011] [Accepted: 08/05/2011] [Indexed: 11/21/2022]
|
8
|
|
9
|
Gozet T, Huynh L, Bohme DK. Generation and dissociation of oxygen- and chloride-bridged iron(III) and manganese(III) tetraphenylporphyrin dimer ions in the gas phase. JOURNAL OF MASS SPECTROMETRY : JMS 2010; 45:35-42. [PMID: 19862766 DOI: 10.1002/jms.1686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Electrospray ionization mass spectrometry (ESI/MS) has allowed the discovery of novel dimer ions emerging from solutions of metalloporphyrin salts and their investigation by collision-induced dissociation (CID) with N(2) molecules. ESI mass spectra have been recorded for the formation of the oxygen or chloride-bridged dimer ions [(FeTPP)(2)OH](+), [(MnTPP)(2)OH](+), [(FeTPP)(2)Cl](+) and [(MnTPP)(2)Cl](+) derived from various solutions of FeTPPCl and MnTPPCl salts. The CID of [(FeTPP)(2)OH](+) proceeds mainly by neutral loss of (FeTPP)OH to form [FeTPP](+) and, to a minor extent, to form the charge-reversed products. The CID of [(MnTPP)(2)OH](+) exhibits exclusively the product ion [MnTPP](+) by loss of neutral (MnTPP)OH. [(FeTPP)(2)Cl](+) and [(MnTPP)(2)Cl](+) dissociate by loss of (Fe/MnTPP)Cl to give rise to [Fe/MnTPP](+). [(FeTPP)(2)O](+) and [(FeTPP)(2)OH](+) were generated from a solution of the dimer, (FeTPP)(2)O. Dissociation of [(FeTPP)(2)O](+) yields two product ions, [FeTPP](+) and [(FeTPP)O](+), with higher onsets compared to the equivalent fragments formed from [(FeTPP)(2)OH](+).
Collapse
Affiliation(s)
- Tuba Gozet
- Department of Chemistry, Center for Research in Mass Spectrometry, York University, Toronto, Ontario, M3J 1P3, Canada
| | | | | |
Collapse
|
10
|
Asher C, de Villiers KA, Egan TJ. Speciation of Ferriprotoporphyrin IX in Aqueous and Mixed Aqueous Solution Is Controlled by Solvent Identity, pH, and Salt Concentration. Inorg Chem 2009; 48:7994-8003. [DOI: 10.1021/ic900647y] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Constance Asher
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| | | | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| |
Collapse
|
11
|
Webster GT, McNaughton D, Wood BR. Aggregated Enhanced Raman Scattering in Fe(III)PPIX Solutions: The Effects of Concentration and Chloroquine on Excitonic Interactions. J Phys Chem B 2009; 113:6910-6. [DOI: 10.1021/jp811028a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Grant T. Webster
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Don McNaughton
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Bayden R. Wood
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
12
|
Egan TJ. Recent advances in understanding the mechanism of hemozoin (malaria pigment) formation. J Inorg Biochem 2008; 102:1288-99. [DOI: 10.1016/j.jinorgbio.2007.12.004] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 10/19/2007] [Accepted: 10/31/2007] [Indexed: 11/15/2022]
|
13
|
Webster GT, Tilley L, Deed S, McNaughton D, Wood BR. Resonance Raman spectroscopy can detect structural changes in haemozoin (malaria pigment) following incubation with chloroquine in infected erythrocytes. FEBS Lett 2008; 582:1087-92. [PMID: 18325340 DOI: 10.1016/j.febslet.2008.02.062] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/25/2008] [Accepted: 02/25/2008] [Indexed: 11/29/2022]
Abstract
Resonance Raman spectroscopy was applied to monitor the effects of chloroquine (CQ) treatment on cultures of Plasmodium falciparum trophozoites. A number of bands assigned to A(1g) and B(1g) modes characteristic of the haemozoin aggregate are reduced in intensity in the CQ-treated cells, however, no bands from the CQ are observed. The intensity changes are attributed to intermolecular drug binding of the CQ in a sandwich type complex between ferriprotoporphyrin IX (FePPIX) dimer units. It is postulated that the CQ binds via pi-pi interactions between adjacent and orientated porphyrins thereby disrupting the haemozoin aggregate and reducing excitonic interactions between adjacent haems. The results show the potential of Raman microscopy as a screening tool for FePPIX:drug interactions in live cells.
Collapse
Affiliation(s)
- Grant T Webster
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Vic. 3800, Australia
| | | | | | | | | |
Collapse
|
14
|
de Villiers KA, Kaschula CH, Egan TJ, Marques HM. Speciation and structure of ferriprotoporphyrin IX in aqueous solution: spectroscopic and diffusion measurements demonstrate dimerization, but not μ-oxo dimer formation. J Biol Inorg Chem 2006; 12:101-17. [PMID: 16972088 DOI: 10.1007/s00775-006-0170-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 08/25/2006] [Indexed: 11/29/2022]
Abstract
Changes in epsilon (393) (the Soret band) of aqueous ferriprotoporphyrin IX [Fe(III)PPIX] with concentration indicate that it dimerizes, but does not form higher aggregates. Diffusion measurements support this observation. The diffusion coefficient of aqueous Fe(III)PPIX is half that of the hydrated monomeric dicyano complex. Much of the apparent instability of aqueous Fe(III)PPIX solutions could be attributed to adsorption onto glass and plastic surfaces. However, epsilon (347) was found to be independent of the aggregation state of the porphyrin and was used to correct for the effects of adsorption. The UV-vis spectrum of the aqueous dimer is not consistent with that expected for a mu-oxo dimer and the (1)H NMR spectrum is characteristic of five-coordinate, high-spin Fe(III)PPIX. Magnetic susceptibility measurements using the Evans method showed that there is no antiferromagnetic coupling in the dimer. By contrast, when the mu-oxo dimer is induced in 10% aqueous pyridine, characteristic UV-vis and (1)H NMR spectra of this species are observed and the magnetic moment is consistent with strong antiferromagnetic coupling. We propose a model in which the spontaneously formed aqueous Fe(III)PPIX dimer involves noncovalent interaction of the unligated faces of two five-coordinate H(2)O/HO-Fe(III)PPIX molecules, with the axial H(2)O/OH(-) ligands directed outwards. This arrangement is consistent with the crystal structures of related five-coordinate iron(III) porphyrins and accounts for the observed pH dependence of the dimerization constant and the spectra of the monomer and dimer. Structures for the aqueous dimer are proposed on the basis of molecular dynamics/simulated annealing calculations using a force field previously developed for modeling metalloporphyrins.
Collapse
Affiliation(s)
- Katherine A de Villiers
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch, 7701, South Africa
| | | | | | | |
Collapse
|
15
|
Egan TJ. Interactions of quinoline antimalarials with hematin in solution. J Inorg Biochem 2006; 100:916-26. [PMID: 16384600 DOI: 10.1016/j.jinorgbio.2005.11.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 11/02/2005] [Accepted: 11/06/2005] [Indexed: 11/26/2022]
Abstract
Quinoline antimalarial drugs such as chloroquine and related compounds are believed to act by targeting ferriprotoporphyrin IX (Fe(III)PPIX) in the form of hematin (H(2)O/HO-Fe(III)PPIX), its mu-oxo dimer ([Fe(III)PPIX](2)O) or crystalline beta-hematin ([Fe(III)PPIX](2)) in the malaria parasite. Fe(III)PPIX is formed when the parasite digests host hemoglobin during its intraerythrocytic blood stage. This has led to a number of studies on the interaction of Fe(III)PPIX with quinoline antimalarials and related compounds. This article reviews the spectroscopy, thermodynamics and structures of Fe(III)PPIX-quinoline complexes in solution.
Collapse
Affiliation(s)
- Timothy J Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
| |
Collapse
|
16
|
Ncokazi KK, Egan TJ. A colorimetric high-throughput β-hematin inhibition screening assay for use in the search for antimalarial compounds. Anal Biochem 2005; 338:306-19. [PMID: 15745752 DOI: 10.1016/j.ab.2004.11.022] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2004] [Indexed: 10/26/2022]
Abstract
Antimalarial drugs such as chloroquine are believed to act by inhibiting hemozoin formation in the food vacuole of the malaria parasite. We have developed a new assay for measuring and detecting inhibition of synthetic hemozoin (beta-hematin) formation. Aqueous pyridine (5% v/v, pH 7.5) forms a low-spin complex with hematin but not with beta-hematin. Its absorbance obeys Beer's law, making it useful for quantitating hematin concentration in hematin/beta-hematin mixtures, allowing compounds to be investigated for inhibition of beta-hematin formation. The assay is rapid (60 min incubation) and requires no centrifugation. The beta-hematin inhibition data show good agreement with alternative assay methods reported by four laboratories. The assay was adapted for high-throughput colorimetric screening, allowing visual identification of beta-hematin inhibitors. In this mode, the assay successfully detected all 18 beta-hematin inhibitors in a set of 47 compounds tested, with no false positive results. The quantitative in vitro antimalarial activities of a set of 13 aminoquinolines and quinoline methanols were found to correlate significantly with beta-hematin inhibition values determined using the assay.
Collapse
Affiliation(s)
- Kanyile K Ncokazi
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| | | |
Collapse
|
17
|
Egan TJ, Combrinck JM, Egan J, Hearne GR, Marques HM, Ntenteni S, Sewell BT, Smith PJ, Taylor D, van Schalkwyk DA, Walden JC. Fate of haem iron in the malaria parasite Plasmodium falciparum. Biochem J 2002; 365:343-7. [PMID: 12033986 PMCID: PMC1222701 DOI: 10.1042/bj20020793] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2002] [Accepted: 05/29/2002] [Indexed: 11/17/2022]
Abstract
Chemical analysis has shown that Plasmodium falciparum trophozoites contain 61+/-2% of the iron within parasitized erythrocytes, of which 92+/-6% is located within the food vacuole. Of this, 88+/-9% is in the form of haemozoin. (57)Fe-Mössbauer spectroscopy shows that haemozoin is the only detectable iron species in trophozoites. Electron spectroscopic imaging confirms this conclusion.
Collapse
Affiliation(s)
- Timothy J Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Goff H, Morgan LO. Amino acid-substituted iron porphyrins. 1. Preparation and aqueous solution properties. Inorg Chem 2002. [DOI: 10.1021/ic50163a010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
|
20
|
Zou JZ, Xu Z, Chen W, Lo K, You XZ. Synthesis, structure and magnetic properties of new polymeric compounds containing manganese(II)–Pzdc (PzdcH2: 2,3-Pyrazinedicarboxylic acid). Polyhedron 1999. [DOI: 10.1016/s0277-5387(99)00019-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
21
|
Egan TJ, Mavuso WW, Ross DC, Marques HM. Thermodynamic factors controlling the interaction of quinoline antimalarial drugs with ferriprotoporphyrin IX. J Inorg Biochem 1997; 68:137-45. [PMID: 9336973 DOI: 10.1016/s0162-0134(97)00086-x] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The interaction of a variety of quinoline antimalarial drugs as well as other quinoline derivatives with strictly monomeric ferriprotoporphyrin IX [Fe(III)PPIX] has been investigated in 40% aqueous DMSO solution. At an apparent pH of 7.5 and 25 degrees C, log K values for bonding are 5.52 +/- 0.03 (chloroquine), 5.39 +/- 0.04 (amodiaquine), 4.10 +/- 0.02 (quinine), 4.04 +/- 0.03 (9-epiquinine), and 3.90 +/- 0.08 (mefloquine). Primaquine, 8-hydroxyquinoline, 5-aminoquinoline, 6-aminoquinoline, 8-aminoquinoline, and quinoline exhibit no evidence of interaction with Fe(III)PPIX. The enthalpy and entropy changes for the interaction of quinolines with Fe(III)PPIX, as determined from the temperature dependence of the log K values, exhibit a compensation phenomenon that is suggestive of hydrophobic interaction. This is supported by the finding that the interactions of chloroquine and quinine with Fe(III)PPIX are weakened by increasing concentrations of acetonitrile. Interactions of chloroquine, quinine, and 9-epiquinine with Fe(III)PPIX are shown to remain strong at pH 5.6, the approximate pH of the food vacuole of the malaria parasite which is believed to be the locus of drug activity. Implications for the design of antimalarial drugs are briefly discussed.
Collapse
Affiliation(s)
- T J Egan
- Department of Chemistry, University of Cape Town, Rondebosch, South Africa.
| | | | | | | |
Collapse
|
22
|
Tompkins GR, Wood DP, Birchmeier KR. Detection and comparison of specific hemin binding by Porphyromonas gingivalis and Prevotella intermedia. J Bacteriol 1997; 179:620-6. [PMID: 9006012 PMCID: PMC178739 DOI: 10.1128/jb.179.3.620-626.1997] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A radioligand assay was designed to detect and compare specific hemin binding by the periodontal anaerobic black-pigmenting bacteria (BPB) Porphyromonas gingivalis and Prevotella intermedia. The assay included physiological concentrations of the hemin-binding protein rabbit serum albumin (RSA) to prevent self-aggregation and nonspecific interaction of hemin with cellular components. Under these conditions, heme-starved P. intermedia cells (two strains) expressed a single binding site species (4,100 to 4,600 sites/cell) with a dissociation constant (Kd) of 1.0 x 10(-9) M. Heme-starved P. gingivalis cells (two strains) expressed two binding site species; the higher-affinity site (1,000 to 1,500 sites/cell) displayed a Kd of between 3.6 x 10(-11) and 9.6 x 10(-11) M, whereas the estimated Kd of the lower-affinity site (1.9 x 10(5) to 6.3 x 10(5) sites/cell) ranged between 2.6 x 10(-7) and 6.5 x 10(-8) M. Specific binding was greatly diminished in heme-replete cells of either BPB species and was not displayed by iron-replete Escherichia coli cells, which bound as much hemin in the absence of RSA as did P. intermedia. Hemin binding by BPB was reduced following treatment with protein-modifying agents (heat, pronase, and N-bromosuccinimide) and was blocked by protoporphyrin IX and hemoglobin but not by Congo red. Hemopexin also inhibited bacterial hemin binding. These findings indicate that both P. gingivalis and P. intermedia express heme-repressible proteinaceous hemin-binding sites with affinities intermediate between those of serum albumin and hemopexin. P. gingivalis exhibited a 10-fold-greater specific binding affinity and greater heme storage capacity than did P. intermedia, suggesting that the former would be ecologically advantaged with respect to heme acquisition.
Collapse
Affiliation(s)
- G R Tompkins
- Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta 30912-1126, USA.
| | | | | |
Collapse
|
23
|
Yushmanov VE, Imasato H, Tominaga TT, Tabak M. H NMR and electronic absorption spectroscopy of paramagnetic water-soluble meso-tetraarylsubstituted cationic and anionic metalloporphyrins. J Inorg Biochem 1996; 61:233-50. [PMID: 8867451 DOI: 10.1016/0162-0134(95)00071-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The ionization, mu-oxo-dimerization and axial ligation equilibria of free bases, iron(III) and manganese(III) derivatives of meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS4) and meso-tetrakis(4-N-methyl-pyridiniumyl)porphyrin (TMPyP) in aqueous solution are studied by 1H NMR and electronic absorption spectroscopy. At physiological pH, Fe(III) complexes of TMPyP and TPPS4 exist predominantly as dimers and may undergo transition to low spin species upon binding to biomolecules, whereas Mn(III) complexes are essentially monomeric. Dicyano and bis-imidazole complexes of FeTMPyP and FeTPPS4 are low spin monomer adducts in the pH range 2.0 to 11.2. No low spin dimeric complexes were found. The low spin monocyano and high spin mono-imidazole complexes of FeTMPyP are formed in acidic and alkaline media, respectively. T1-relaxation enhancement of water protons at 200 MHz induced by FeTPPS4 falls dramatically in the sequence high spin >> dimeric > low spin form.
Collapse
Affiliation(s)
- V E Yushmanov
- Instituto de Química de São Carlos, Universidade de São Paulo, Brasil
| | | | | | | |
Collapse
|
24
|
Li J, Zou J, Wu M, Xu Z, You X, Mak TC. Synthesis, crystal structure and magnetic properties of oxo-bridged binuclear iron(III) complex [Fe(phen)2PhCOO]2OCl2·7H2O. Polyhedron 1995. [DOI: 10.1016/0277-5387(95)00199-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
25
|
Salehi A, Shirazi A, Bruice TC. Propensity toward formation of higher aggregates in anionic and cationic iron tetraphenylporphyrin μ-oxo dimers: evidence from 1H and 13C NMR spectroscopy. Inorganica Chim Acta 1992. [DOI: 10.1016/s0020-1693(00)85832-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
26
|
Takagi S, Miyamoto T, Hamaguchi M, Sasaki Y, Matsumura T. Synthesis and characterization of tetrakis(2,6-difluorophenyl)porphinato ruthenium(II)(CO)(N-MeIm); oxidation reaction of hydrocarbon catalyzed by the ruthenium porphyrin. Inorganica Chim Acta 1990. [DOI: 10.1016/s0020-1693(00)80216-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
27
|
Helpern JA, Curtis JC, Hearshen D, Smith MB, Welch KM. The development of a pH-sensitive contrast agent for NMR 1H imaging. Magn Reson Med 1987; 5:302-5. [PMID: 3431400 DOI: 10.1002/mrm.1910050313] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Fe(III)meso-tetra(4-sulfonatophenyl)porphine (Fe-TPPS4) has been investigated as a potential pH-sensitive nuclear magnetic resonance (NMR) proton image contrast agent. Relaxation rates (1/T1 and 1/T2) of water protons were measured as a function of pH and concentration of Fe-TPPS4 in phosphate-buffered isotonic saline. Transverse relaxation rates (1/T2) did not change appreciably with pH above 6.0. Longitudinal relaxation rates (1/T1) increased significantly between pH 7.75 and 5.75. This effect was more pronounced with the increasing concentration of Fe-TPPS4 from 0.1 to 1.5 mM and is attributed to a pH-dependent equilibrium between the high-spin (S = 5/2) Fe-TPPS4 monomer at low pH and the antiferromagnetically coupled mu-oxodimer O-(FeTPPS4)2 at high pH. The efficacy of this pH-dependent contrast agent is demonstrated in vitro.
Collapse
Affiliation(s)
- J A Helpern
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan 48202
| | | | | | | | | |
Collapse
|
28
|
Ookubo S, Nozawa T, Hatano M. Spin, oxidation, and ligand states of p-nitrothiophenolatoiron(III) complex of protoporphyrin-IX-dimethylester in the presence of 1-MeIm: magnetic circular dichroism and 1H nuclear magnetic resonance spectroscopic studies. J Inorg Biochem 1987; 29:1-23. [PMID: 3559544 DOI: 10.1016/0162-0134(87)80008-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Complex formation of 5-coordinated iron(III) heme containing thiolate anion (p-nitrothiophenol) with imidazole (1-methylimidazole) showed very interesting features depending on the nature of the solvent and the ratio of the ligand to heme. The complexes formed under different conditions were not only low spin iron(III) complexes with a thiolate anion and an imidazole or with two imidazoles, but also reduced (iron(II] complexes with a thiolate and an imidazole or with two imidazoles. Absorption, magnetic circular dichroism, and 1H NMR spectroscopies could identify the complex formed when they were used concurrently. The dependence of polarity of the solvents used on the resultant chemical species was ascribed to the stability of Fe(III) or Fe(II) complex in the different solvents. The iron(III) complex with a thiolate anion and an imidazole was found to be reduced automatically to the iron(II) complex with a thiolate and an imidazole which exchanged ligand to the iron(II) bisimidazoles in the presence of excess imidazole. This study showed that the ligands of heme are easily exchanged and that the heme iron(III) is automatically reduced in several conditions. Possible significance with respect to biological systems containing a sulfur ligand is discussed.
Collapse
|
29
|
Sievers G, Häkli H, Luhtala J, Tenhunen R. Optical and EPR spectroscopy studies on haem arginate, a new compound used for treatment of porphyria. Chem Biol Interact 1987; 63:105-14. [PMID: 2822264 DOI: 10.1016/0009-2797(87)90091-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A protohaem compound, used for treatment of porphyrias, has been studied to elucidate its state of aggregation. EPR and absorption spectroscopy measurements reveal that 38.3 mM protohaem, dissolved in 40% 1,2-propanediol/10% ethanol/water solution, also containing 153 mM arginine, is partly EPR silent. It exists as high molecular weight aggregates and probably also as mu-oxo-dimers. Dilution in the aqueous alcohol solution dissolves the aggregates first to oligomers and dimers, and finally to monomers (Kdiss = 24 X 10(-6)M). When haem is diluted in 0.9% sodium chloride, a fully monomeric state is not reached even at 1 microM concentration. At 3.5 microM concentration, that used for infusion in patients, the haem is still totally aggregated.
Collapse
Affiliation(s)
- G Sievers
- Department of Biochemistry, University of Helsinki, Finland
| | | | | | | |
Collapse
|
30
|
Diammonium ?-oxobis[trichloroferrate(III)] salts. Crystal and molecular structure of bis(benzyldimethylphenylammonium) ?-oxobis(trichloroferrate). ACTA ACUST UNITED AC 1986. [DOI: 10.1007/bf01161037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
31
|
Silver J, Hamed MY, Morrison IE. Studies of the reactions of ferric iron with glutathione and some related thiols. Part V. Solid complexes containing FeII and glutathione or FeIII with oxidized glutathione. Inorganica Chim Acta 1985. [DOI: 10.1016/s0020-1693(00)80699-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
Boersma AD, Goff HM. Solution characterization of a new iron(III) porphyrin hydrolyzed complex. Inorganica Chim Acta 1984. [DOI: 10.1016/s0020-1693(00)82341-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
33
|
Bickar D, Bonaventura C, Bonaventura J. Carbon monoxide-driven reduction of ferric heme and heme proteins. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90579-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
34
|
Ahmad MB, Kincaid JR. Haem disorder in modified myoglobins. Effect of reconstitution procedures. Biochem J 1983; 215:117-22. [PMID: 6626170 PMCID: PMC1152370 DOI: 10.1042/bj2150117] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Apomyoglobin was reconstituted with deuterohaem derivatives under various conditions. The fraction of disordered component, which is characterized by a 180 degree rotation of the haem group, for the various preparations was determined by n.m.r. spectroscopy. By using the procedures described, it was shown that the fraction of disordered component is minimized if the reconstitution is carried out with high-spin ferric haem derivatives within an experimentally determined optimum pH range of 8-9.5. Use of low-spin derivatives in either the ferrous or ferric forms leads to substantial increases in the fraction of disordered form. Attempted removal of the disordered form by selective oxidation and chromatographic purification was not effective.
Collapse
|
35
|
|
36
|
|
37
|
|
38
|
Smith TD, Gaunt R, Ruzic I. Hydroxylation of aniline by hemin-thiol compound solubilised by non-ionic detergents: A model system of cytochrome P-450. Inorganica Chim Acta 1983. [DOI: 10.1016/s0020-1693(00)86497-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
39
|
Cocolios P, Moise C, Guilard R. Liaisons metal—metal en serie porphyrinique. premiers exemples d'indioporphyrines a motifs bi-ou tri-nucleaires. J Organomet Chem 1982. [DOI: 10.1016/s0022-328x(00)87102-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Smith P, James B, Dolphin D. Structural aspects and coordination chemistry of metal porphyrin complexes with emphasis on axial ligand binding to carbon donors and mono- and diatomi. Coord Chem Rev 1981. [DOI: 10.1016/s0010-8545(00)80511-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
41
|
Walsh TA, Johnson MK, Barber D, Thomson AJ, Greenwood C. Studies on heme d1 extracted from Pseudomonas aeruginosa nitrite reductase. J Inorg Biochem 1981; 14:15-31. [PMID: 6260897 DOI: 10.1016/s0162-0134(00)80011-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Heme d1 has been extracted from Pseudomonas nitrite reductase. Imidazole, cyanide, and chloride-ferroheme, and CO, NO, cyanide, imidazole, and pyridine-ferroheme complexes have been prepared for study by UV/vis spectroscopy, and in some cass by epr and low-temperature mcd as well. Iron determinations have been carried out to assess extinction coefficients. Absorption spectra were used to monitor the transition of chloride-ferriheme d1 to an alkaline form of ferriheme d1 and a pka of 6.5 was determined for the process. The epr spectrum of chloride-ferriheme possessed the characteristic g = 6 signal of high spin (S = 5/2) iron, but the alkaline-ferriheme form gave no detectable epr signals. Electron paramagnetic resonance spectra were also obtained for cyanide and imidazole-ferriheme d1 and for NO-ferroheme d1. The imidazole complex gave signals that were very weak in comparison with the cyanide complex, but mcd measurements of imidazole-ferriheme d1 were consistent with it being a low-spin (S = 1/2) system. The epr signals of NO-ferroheme d1 were similar to those of the corresponding holo-enzyme complex. Reduction of alkaline-ferriheme d1 was found to be affected by the presence of oxygen, but under N2 give the same result with ascorbate and dithionite. Autoreduction of alkaline-ferriheme d1 was observed when placed under CO, and NO, atmospheres, or when treated with pyridine.
Collapse
|
42
|
Phillippi MA, Goff HA. A convenient and rapid synthesis of mesohemin IX dimethyl ester chloride. Inorganica Chim Acta 1980. [DOI: 10.1016/s0020-1693(00)84133-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
43
|
Ruf HH, Wende P, Ullrich V. Models for ferric cytochrome P450. Characterization of hemin mercaptide complexes by electronic and ESR spectra. J Inorg Biochem 1979; 11:189-204. [PMID: 229198 DOI: 10.1016/s0162-0134(00)80017-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hemin coordinated with mercaptide sulfur as fifth ligand and various sixth ligands were investigated as models for cytochrome P450 in its native ferric low-spin state and its ligand complexes. Mixing the hemin with its ligands below -60 degrees C prevented the reduction of the hemin by mercaptide and made it possible to characterize each sample both by electronic and ESR spectra. Excess of mercaptide formed hemin-dimercaptide complexes with hyperporphyrin spectra with two Soret bands around 380 and 370 nm. The second mercaptide could be exchanged by other ligands with hydroxyl, phosphine, thioether, isocyanide, amine, imidazole, and pyridine groups. The comparison of these spectral data with cytochrome P450 substantiates mercaptide as the fifth ligand and makes a hydroxyl group a more likely candidate for the native sixth ligand than an imidazole group.
Collapse
|
44
|
Yoshimura T, Ozaki T. Equilibria of Imidazole Derivatives with (Protoporphyrin IX dimethyl ester)iron(III) Chloride. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1979. [DOI: 10.1246/bcsj.52.2268] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
45
|
Goff H. Carbon-13 nuclear magnetic resonance spectroscopy of high-spin iron(III) porphyrin compounds. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 542:348-55. [PMID: 687661 DOI: 10.1016/0304-4165(78)90030-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
13C nuclear magnetic resonance spectra have been obtained for a variety of high-spin iron(III) porphyrin compounds and corresponding mu-oxo-bridged dimeric species. Large hyperfine shifts and significant line broadening are observed. The monomeric complexes exhibit hyperfine shifts which are downfield with the exception of an upfield shift for the meso-carbon atom. Possible unpaired spin delocalization mechanisms and prospects for observing 13C NMR porphyrin resonances in high-spin ferrihemoproteins are discussed. Spectra reported here provide strategy for incorporation of 13C labels in hemoproteins either by biosynthetic or chemical means. The vinyl-CH2 resonances of iron(III) protoporphyrin IX located 260 parts per million downfield from tetramethylsilane are especially attractive from the standpoint of chemical labeling.
Collapse
|
46
|
|
47
|
|
48
|
Giddings GG. The basis of color in muscle foods. CRC CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 1977; 9:81-114. [PMID: 336284 DOI: 10.1080/10408397709527231] [Citation(s) in RCA: 82] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
49
|
|