Back to Search
Start Over
Export of a Heterologous Cytochrome P450 (CYP105D1) in Escherichia coli Is Associated with Periplasmic Accumulation of Uroporphyrin.
- Source :
-
Journal of Biological Chemistry . 11/14/2003, Vol. 278 Issue 46, p45555-45562. 8p. 1 Diagram, 2 Charts, 10 Graphs. - Publication Year :
- 2003
-
Abstract
- This report suggests an important physiological role of a CYP in the accumulation of uroporphyrin I arising from catalytic oxidative conversion of uroporphyrinogen I to uroporphyrin I in the periplasm of Escherichia coli cultured in the presence of 5-aminolevulinic acid. A structurally competent Streptomyces griseus CYP105D1 was expressed as an engineered, exportable form in aerobically grown E. coli. Its progressive induction in the presence of 5-aminolevulinic acid-supplemented medium was accompanied by an accumulation of a greater than 100-fold higher amount of uroporphyrin I in the periplasm relative to cells lacking CYP105DI. Expression of a cytoplasm-resident engineered CYP105D1 at a comparative level to the secreted form was far less effective in promoting porphyrin accumulation in the periplasm. Expression at a 10-fold molar excess over the exported CYP105D1 of another periplasmically exported hemoprotein, the globular core of cytochrome b[sub 5], did not substitute the role of the periplasmically localized CYP105D1 in promoting porphyrin production. This, therefore, eliminated the possibility that uroporphyrin accumulation is merely a result of increased hemoprotein synthesis. Moreover, in the strain that secreted CYP105D1, uroporphyrin production was considerably reduced by azole-based P450 inhibitors. Production of both holo-CYP105D1 and uroporphyrin was dependent upon 5-aminolevulinic acid, except that at higher concentrations this resulted in a decrease in uroporphyrin. This study suggests that the exported CYP105D1 oxidatively catalyzes periplasmic conversion of uroporphyrinogen I to uroporphyrin I in E. coli. The findings have significant implications in the ontogenesis of human uroporphyria-related diseases. [ABSTRACT FROM AUTHOR]
- Subjects :
- *CYTOCHROME P-450
*CYTOCHROMES
*ESCHERICHIA coli
Subjects
Details
- Language :
- English
- ISSN :
- 00219258
- Volume :
- 278
- Issue :
- 46
- Database :
- Academic Search Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11566198
- Full Text :
- https://doi.org/10.1074/jbc.M212685200