Clinical Chemistry of the Porphyrins

Eales, L

doi:10.1016/b978-0-12-220106-6.50018-8

Cited by 11 publications

(2 citation statements)

References 229 publications

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“…Soluble and insoluble VHb polypeptide levels were determined by quantitative SDS-PAGE. Heme levels were determined by the pyridine hemochromogen assay using visible difference absorption spectroscopy (4).…”

Section: Methodsmentioning

confidence: 99%

Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli

Hart

Kallio

Bailey

1994

Appl Environ Microbiol

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Vitreoscilla hemoglobin (VHb) is accumulated at high levels in both soluble and insoluble forms when expressed from its native promoter on a pUC19-derived plasmid in Escherichia coli. Examination by atomic absorption spectroscopy and electron paramagnetic resonance spectroscopy revealed that the insoluble form uniformly lacks the heme prosthetic group (apoVHb). The purified, soluble form contains heme (holoVHb) and is spectroscopically indistinguishable from holoVHb produced by VitreosciMla cells. This observation suggested that a relationship may exist between the insolubility of apoVHb and biosynthesis of heme. To examine this possibility, a series of experiments were conducted to chemically and genetically manipulate the formation and conversion of 5-aminolevulinic acid (ALA), a key intermediate in heme biosynthesis. Chemical perturbations involved supplementing the growth medium with the intermediate ALA and the competitive inhibitor levulinic acid which freely cross the cell barrier. Genetic manipulations involved amplifying the gene dosage for the

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Section: Methodsmentioning

confidence: 99%

Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli

Hart

Kallio

Bailey

1994

Appl Environ Microbiol

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“…A hematoporphyrin derivative, Photofrin (dihematoporphyrin ether and/or ester) (Axcan Pharma, Quebec, Canada) is used as the photosensitizer in PDT. Hematoporphyrin derivatives exhibit red fluorescence when light of wavelengths around 405nm is radiated [3]. It is reported that Photofrin is retained selectively by tumor tissue compared with most normal tissues [4] except the liver, spleen, and kidney [5,6].…”

mentioning

confidence: 99%

Detection of Photofrin Fluorescence From Malignant and Premalignant Lesions in the Bronchus using a Full‐color Endoscopic Fluorescence Imaging System

Ohsaki

Takeyama

Nakao

et al. 2001

Diagnostic and Therapeutic Endoscopy

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Study objectives: To detect invisible lung cancer and to determine field of laser radiation during PDT we developed a full-color fluorescence fiberscopic system. We tested the efficacy of this system in patients with various bronchial malignancies. System design: A fiber-optic endoscope was attached to a camera box containing a color ICCD camera which can detect from 400 to 700nm fluorescence in full-color. Light of average wavelength 405 nm was selected and radiated through the light channel of the fiberscope from a 300W Xenon lamp. Patients and methods: We examined nine consecutive patients with bronchial malignancy admitted in our hospital to receive PDT. Sixteen lesions in these nine patients were observed with white light and excitation light and the results were compared. Histological examinations were done by taking biopsy specimens and samples for pathological and cytological examination. After the diagnosis was confirmed, 2.0 mg/kg Photofrin was injected. Forty eight hours after the administration of Photofrin, observation of the bronchial wall was made using a full-color endoscopic fluorescence imaging system just before PDT. Results: Bright red fluorescence from Photofrin was Observed in 14/14 bronchial malignancies: 3 squamous cell carcinoma, 9 squamous cell carcinoma in situ, 1 metastatic breast cancer and 1 metastatic islet cell tumor. Bright red fluorescence was also detected in 2/2 squamous dysplasia. Green autofluorescence was observed in the normal part of the bronchus. Conclusions: Results of the present study suggest that the full-color endoscopic fluorescence imaging system can be used to detect malignant and premalignant lesions as red fluorescence against green autofluorescence with Photofrin administration, and this system has the potential to detect absence of autofluorescence in cancerous lesions.

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Iron Porphyrin Chemistry

Walker¹,

Simonis²

2005

Encyclopedia of Inorganic Chemistry

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This article reviews most aspects of the chemistry of iron porphyrins, from Fe(0) to Fe(V), including occurrence and roles of natural iron porphyrins (hemes) and their synthetic analogs, structures and electron configurations of iron porphyrins of all oxidation and spin states, π electron configuration of the porphyrin ring, synthesis of metal‐free porphyrins and other related macrocycles, insertion of iron into free‐base porphyrins and related macrocycles, the properties, reactions, uses and biological relevance of iron(0), ‐(I), ‐(II) porphyrins (the latter with S = 0, 1, and 2 spin state possibilities), of iron(II) porphyrin π‐cation radicals, of iron(III) porphyrins (with S = 1/2, 3/2, and 5/2 spin state possibilities), of iron(III) porphyrin and corrole π‐cation radicals, of iron(IV) porphyrins (including five‐ and six‐coordinate ferryl (FeO) 2+ , iron(IV) phenyl, carbene and hydrazine complexes, and the bis‐methoxide complex) and a comparison of iron(IV) porphyrins to iron(III) porphyrin π‐cation radicals, of iron(IV) porphyrin π‐cation radicals, and of the possible existence of iron(V) porphyrins. Included in the Fe(II) part are sections on addition of ligands to four‐coordinate iron(II) porphyrins, including equilibrium binding constants, photodissociation of ligands from PFeL 2 complexes, binding of small molecules (O 2 , CO, NO, HNO) to 5‐coordinate iron(II) porphyrins and design of porphyrin ligands that will mimic the active sites of heme proteins such as myoglobin and hemoglobin, the cytochromes P450 and nitric oxide synthases, and the nitrophorins and guanylyl cyclases. Included in the iron(III) part are sections on both 5‐ and 6‐coordinate high‐spin complexes and their similarities and differences, bridged or through‐space magnetically coupled complexes of high‐spin iron(III) porphyrins with other metal complexes as possible models for cytochrome oxidase and the assimilatory sulfite reductases, coupled oxidation of hemes by hydrogen peroxide or its equivalent, and the relationship of this reactivity to the reactions of heme oxygenase, iron(III) porphyrins as reduction catalysts, and photochemistry of iron(III) porphyrins, possible electron configurations of low‐spin iron(III) porphyrins, the phenomenon and possible electronic consequences of ruffling of the porphinato core in iron(III) porphyrins, the preferred orientation of planar axial ligands bound to low‐spin iron(III) porphyrins, NO complexes of iron(III) porphyrins, reduction potentials, equilibrium constants and rates of axial‐ligand addition and exchange, kinetics of axial‐ligand rotation and porphyrin ring inversion, kinetics of reduction and autoreduction of iron(III) porphyrins, electron self‐exchange between low‐spin iron(III) and iron(II) porphyrins, synthetic ferriheme proteins, and synthesis of five‐coordinate low‐spin iron(III) porphyrins having σ‐alkyl or σ‐aryl groups as axial ligands. The iron(IV) and iron(IV) cation radical sections discuss the high‐valent states of cytochromes P450 and related enzymes.

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Clinical Chemistry of the Porphyrins

Cited by 11 publications

References 229 publications

Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli

Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli

Detection of Photofrin Fluorescence From Malignant and Premalignant Lesions in the Bronchus using a Full‐color Endoscopic Fluorescence Imaging System

Iron Porphyrin Chemistry

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