Understanding electron transport systems of Streptomyces cytochrome P450

2006 ◽  
Vol 34 (6) ◽  
pp. 1183-1185 ◽  
Author(s):  
Y.-J. Chun ◽  
T. Shimada ◽  
M.R. Waterman ◽  
F.P. Guengerich
Keyword(s):  
Cytochrome P450 ◽  
Electron Transport ◽  
Streptomyces Coelicolor ◽  
Genomic Analysis ◽  
Biologically Active ◽  
Transport Systems ◽  
Cytochrome P450 Enzymes ◽  
Streptomyces Spp ◽  
Fatty Acid Hydroxylation ◽  
Acid Hydroxylation

Streptomyces spp. are known to produce various types of biologically active compounds including antibiotics, antiparasitic agents, herbicides and immunosuppressants. P450 (cytochrome P450) enzymes may have key roles in these biosynthetic and biotransformation reactions. Recent genomic analysis of Streptomyces coelicolor A3(2) indicates that S. coelicolor may have six ferredoxins (Fdxs), four putative Fdx reductases (FdRs) and 18 P450 genes. However, there are few clues to explain the mechanisms and functions of Streptomyces P450 systems. To solve these questions, we have expressed and purified five S. coelicolor P450s, four FdRs and six Fdxs in Escherichia coli. Of the purified P450s, CYP105D5 has fatty acid hydroxylation activity in a system reconstituted with putidaredoxin reductase and Fdx4 or with spinach FdR and spinach Fdx, although the reconstitutions with FdR2 or FdR3 and any of the Fdxs did not support CYP105D5-catalysed oleic acid hydroxylation. Elucidation of the detailed mechanisms of electron transport system for Streptomyces P450 may provide the perspective for usefulness of P450s as a biocatalyst.

scholarly journals Substrate Recognition and Molecular Mechanism of Fatty Acid Hydroxylation by Cytochrome P450 fromBacillus subtilis

2003 ◽  
Vol 278 (11) ◽  
pp. 9761-9767 ◽  
Author(s):  
Dong-Sun Lee ◽  
Akari Yamada ◽  
Hiroshi Sugimoto ◽  
Isamu Matsunaga ◽  
Hisashi Ogura ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Fatty Acid ◽  
Molecular Mechanism ◽  
Substrate Recognition ◽  
Fatty Acid Hydroxylation ◽  
Acid Hydroxylation

scholarly journals Biocatalytic Conversion of Avermectin to 4"-Oxo-Avermectin: Heterologous Expression of the ema1 Cytochrome P450 Monooxygenase

2005 ◽  
Vol 71 (11) ◽  
pp. 6977-6985 ◽  
Author(s):  
István Molnár ◽  
D. Steven Hill ◽  
Ross Zirkle ◽  
Philip E. Hammer ◽  
Frank Gross ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Electron Transport ◽  
Heterologous Expression ◽  
Streptomyces Coelicolor ◽  
Cytochrome P450 Monooxygenase ◽  
Streptomyces Avermitilis ◽  
P450 Monooxygenase ◽  
Tta Codon ◽  
Solvent Tolerant ◽  
Regioselective Oxidation

ABSTRACT The cytochrome P450 monooxygenase Ema1 from Streptomyces tubercidicus R-922 and its homologs from closely related Streptomyces strains are able to catalyze the regioselective oxidation of avermectin into 4"-oxo-avermectin, a key intermediate in the manufacture of the agriculturally important insecticide emamectin benzoate (V. Jungmann, I. Molnár, P. E. Hammer, D. S. Hill, R. Zirkle, T. G. Buckel, D. Buckel, J. M. Ligon, and J. P. Pachlatko, Appl. Environ. Microbiol. 71:6968-6976, 2005). The gene for Ema1 has been expressed in Streptomyces lividans, Streptomyces avermitilis, and solvent-tolerant Pseudomonas putida strains using different promoters and vectors to provide biocatalytically competent cells. Replacing the extremely rare TTA codon with the more frequent CTG codon to encode Leu4 in Ema1 increased the biocatalytic activities of S. lividans strains producing this enzyme. Ferredoxins and ferredoxin reductases were also cloned from Streptomyces coelicolor and biocatalytic Streptomyces strains and tested in ema1 coexpression systems to optimize the electron transport towards Ema1.

The role of benzoquinones in the electron transport system

1963 ◽  
Vol 157 (968) ◽  
pp. 355-366 ◽  
Keyword(s):  
Steady State ◽  
Electron Transport ◽  
State Level ◽  
Biologically Active ◽  
Transport Systems ◽  
Steady State Level ◽  
Ciba Foundation Symposium ◽  
Photo Oxidation ◽  
The Past

During the past few years two new classes of benzoquinones have been added to the list of biologically active quinone compounds, namely the ubiquinones and the plastoquinones. Consideration has also been given to the possible functions of the vitamins tocopherol and vitamin K in electron-transport systems (Slater 1959; Martius 1960); but contradictory views have not so far been reconciled. The importance of ubiquinones was quickly recognized and indeed it was their participation in oxidative phosphorylation which led to their discovery (Ciba Foundation Symposium 1960). In accordance with the value of their redox potential they link the succinate and the NADH oxidation systems to the cytochrome chain (Green 1962). At the time when identification of the ubiquinones was proceeding, a different benzoquinone was found in leaves (Lester & Crane 1959). Its structure proved to be dimethyl-solanosyl-benzoquinone (Trenner, leads to an increase in the steady-state level of in the leaf, and on removal of light this steady-state level falls to the value previously recorded in the darkened leaf. The photo-oxidation of ascorbic acid is suppressed on poisoning the leaf with cyanide, and at the same time the steady-state level of is enhanced in the darkened leaf. With such poisoned leaves light stimulates the reduction of DHA , and the rate again depends on the intensity of illumination.

scholarly journals Metabolism and Interactions of Chloroquine and Hydroxychloroquine with Human Cytochrome P450 Enzymes and Drug Transporters

2020 ◽  
Vol 21 (14) ◽  
pp. 1127-1135
Author(s):  
Slobodan Rendic ◽  
Frederick Peter Guengerich
Keyword(s):  
Cytochrome P450 ◽  
Inflammatory Diseases ◽  
Drug Transporters ◽  
Transport Systems ◽  
Cytochrome P450 Enzymes ◽  
Human Cytochrome ◽  
Metabolic Properties ◽  
P450 2D6

Background:: In clinical practice, chloroquine and hydroxychloroquine are often co-administered with other drugs in the treatment of malaria, chronic inflammatory diseases, and COVID-19. Therefore, their metabolic properties and the effects on the activity of cytochrome P450 (P450, CYP) enzymes and drug transporters should be considered when developing the most efficient treatments for patients. Methods:: Scientific literature on the interactions of chloroquine and hydroxychloroquine with human P450 enzymes and drug transporters, was searched using PUBMED.Gov (https://pubmed.ncbi.nlm.nih.gov/) and the ADME database (https://life-science.kyushu.fujitsu.com/admedb/). Results:: Chloroquine and hydroxychloroquine are metabolized by P450 1A2, 2C8, 2C19, 2D6, and 3A4/5 in vitro and by P450s 2C8 and 3A4/5 in vivo by N-deethylation. Chloroquine effectively inhibited P450 2D6 in vitro; however, in vivo inhibition was not apparent except in individuals with limited P450 2D6 activity. Chloroquine is both an inhibitor and inducer of the transporter MRP1 and is also a substrate of the Mate and MRP1 transport systems. Hydroxychloroquine also inhibited P450 2D6 and the transporter OATP1A2. Conclusions:: Chloroquine caused a statistically significant decrease in P450 2D6 activity in vitro and in vivo, also inhibiting its own metabolism by the enzyme. The inhibition indicates a potential for clinical drug-drug interactions when taken with other drugs that are predominant substrates of the P450 2D6. When chloroquine and hydroxychloroquine are used clinically with other drugs, substrates of P450 2D6 enzyme, attention should be given to substrate-specific metabolism by P450 2D6 alleles present in individuals taking the drugs.

Biocatalytic conversion of avermectin into 4″-oxo-avermectin: discovery, characterization, heterologous expression and specificity improvement of the cytochrome P450 enzyme

2006 ◽  
Vol 34 (6) ◽  
pp. 1236-1240 ◽  
Author(s):  
I. Molnár ◽  
V. Jungmann ◽  
J. Stege ◽  
A. Trefzer ◽  
J.P. Pachlatko
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Electron Transport ◽  
Natural Product ◽  
High Throughput Screening ◽  
Streptomyces Coelicolor ◽  
Cytochrome P450 Enzyme ◽  
Expression Systems ◽  
P450 Enzyme ◽  
Solvent Tolerant

4″-Oxo-avermectin is a key intermediate in the manufacture of the insecticide emamectin benzoate from the natural product avermectin. Seventeen Streptomyces strains with the ability to oxidize avermectin to 4″-oxo-avermectin in a regioselective manner have been discovered, and the enzymes responsible for this reaction were found to be CYPs (cytochrome P450 mono-oxygenases). The genes for these enzymes have been cloned, sequenced and compared to reveal a new subfamily of CYPs. The biocatalytic enzymes have been overexpressed in Escherichia coli, Streptomyces lividans and solvent-tolerant Pseudomonas putida strains using different promoters and vectors. FDs (ferredoxins) and FREs (ferredoxin:NADP+ reductases) were also cloned from Streptomyces coelicolor and biocatalytic Streptomyces strains, and tested in co-expression systems to optimize the electron transport. Subsequent studies showed that increasing the biocatalytic conversion levels to commercial relevance results in the production of several side products in significant amounts. Chimaeric Ema CYPs were created by sequential rounds of GeneReassembly™, a proprietary directed evolution method, and selected for improved substrate specificity by high-throughput screening.

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