Warning: Undefined array key "mm" in /www/wwwroot/www.ai-bt.com/si.php on line 10 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in /www/wwwroot/www.ai-bt.com/si.php on line 10 The mechanism of potentiation of horseradish peroxidase-catalysed oxidation of NADPH by porphyrins.

Literature DB >> 3036094

The mechanism of potentiation of horseradish peroxidase-catalysed oxidation of NADPH by porphyrins.

J Van Steveninck, J P Boegheim, T M Dubbelman, J Van der Zee.

Abstract

Several porphyrins, including HpD (haematoporphyrin derivative), potentiate the oxidation of NADPH by horseradish peroxidase/H2O2. To elucidate the mechanism of potentiation, the following observations are relevant. During peroxidase-catalysed NADPH oxidation, O2-.(superoxide radical) is generated, as judged from superoxide dismutase-inhibitable cytochrome c reduction. This generation of O2-. is suppressed by HpD. Peroxidase-catalysed NADPH oxidation is stimulated by superoxide dismutase and by anaerobic conditions. Under anaerobic conditions HpD has no influence on peroxide-catalysed NADPH oxidation. Previous studies have shown that horseradish peroxidase is inhibited by O2-.. Thus the experimental results indicate that the potentiating effect of HpD can be explained by its ability to inhibit O2-. generation in the horseradish peroxidase/H2O2/NADPH system.

Entities: Chemical Species

Mesh：

Substances：

Year: 1987 PMID： 3036094 PMCID： PMC1147749 DOI： 10.1042/bj2420611

Source DB: PubMed Journal: Biochem J ISSN： 0264-6021 Impact factor: 3.857

5 in total

1. Excitation of eosin when catalyzing electron transport in biochemical systems.

Authors: B Kachar; K Zinner; C C Vidigal; Y Shimizu; G Cilento
Journal: Arch Biochem Biophys Date: 1979-06 Impact factor: 4.013

2. In vitro cellular effects of hematoporphyrin derivative.

Authors: M W Berns; A Dahlman; F M Johnson; R Burns; D Sperling; M Guiltinan; A Siemens; R Walter; W Wright; M Hammer-Wilson; A Wile
Journal: Cancer Res Date: 1982-06 Impact factor: 12.701

Review 3. Biological effects of the superoxide radical.

Authors: I Fridovich
Journal: Arch Biochem Biophys Date: 1986-05-15 Impact factor: 4.013

4. The non-photosensitized potentiation by the photosensitizer hematoporphyrin of the horseradish peroxidase-catalyzed H2O2-mediated oxidation of NADPH to NADP+.

Authors: R S Bodaness
Journal: Biochem Biophys Res Commun Date: 1984-01-13 Impact factor: 3.575

5. Photoradiation therapy for the treatment of malignant tumors.

Authors: T J Dougherty; J E Kaufman; A Goldfarb; K R Weishaupt; D Boyle; A Mittleman
Journal: Cancer Res Date: 1978-08 Impact factor: 12.701

5 in total

6 in total

The mechanism of potentiation of horseradish peroxidase-catalysed oxidation of NADPH by porphyrins.

1. Excitation of eosin when catalyzing electron transport in biochemical systems.

2. In vitro cellular effects of hematoporphyrin derivative.

Review 3. Biological effects of the superoxide radical.

4. The non-photosensitized potentiation by the photosensitizer hematoporphyrin of the horseradish peroxidase-catalyzed H2O2-mediated oxidation of NADPH to NADP+.

5. Photoradiation therapy for the treatment of malignant tumors.

1. Toxic dark effects of protoporphyrin on the cytochrome P-450 system in rat liver microsomes.

Review 2. Interaction of porphyrins with heme proteins--a brief review.

3. Thiols as myeloperoxidase-oxidase substrates.

4. Hematoporphyrin interacts with myoglobin and alters its functions.

5. Protoporphyrin IX-induced structural and functional changes in human red blood cells, haemoglobin and myoglobin.

6. The influence of porphyrins on iron-catalysed generation of hydroxyl radicals.