Arfificial P450/reductase fusion enzymes: What can we learn from their structures?

Biochimie ◽  
1995 ◽  
Vol 77 (7-8) ◽  
pp. 594-603 ◽  
Author(s):  
Y. Yabusaki
Keyword(s):  
P450 Reductase ◽  
Fusion Enzymes

Fatty Liver and Impaired Hepatic Metabolism Alters the Congener-Specific Distribution of Polychlorinated Biphenyls (PCBs) in Mice with a Liver-Specific Deletion of Cytochrome P450 Reductase

2020 ◽  
Author(s):  
Xueshu Li ◽  
Chun-Yun Zhang ◽  
Hans-Joachim Lehmler
Keyword(s):  
Cytochrome P450 ◽  
Polychlorinated Biphenyls ◽  
Fatty Liver ◽  
Partition Coefficients ◽  
Hepatic Metabolism ◽  
Gas Chromatography Mass Spectrometry ◽  
Cytochrome P450 Reductase ◽  
P450 Reductase ◽  
Specific Distribution ◽  
Specific Deletion

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are linked to adverse health outcomes. PCB tissue levels are determinants of PCB toxicity; however, it is unclear how factors, such as an altered metabolism and/or a fatty liver, affect PCB distribution in vivo. We determined the congener-specific disposition of PCBs in mice with a liver specific deletion of cytochrome P450 reductase (KO), a model of fatty liver with impaired hepatic metabolism, and wildtype (WT) mice. Male and female KO and WT mice were exposed orally to Aroclor 1254, a technical PCB mixture. PCBs were quantified in adipose, blood, brain and liver tissues by gas chromatography-mass spectrometry. PCB profiles and levels in tissues were genotype and sex dependent. PCB levels were higher in the liver from KO compared to WT mice. PCB profiles showed clear differences between tissues from the same exposure group. While experimental tissue : blood partition coefficients in KO and WT mice did not follow the trends predicted using a composition-based model, the agreement between experimental and calculated partition coefficients was still reasonable. Thus, a fatty liver and/or an impaired hepatic metabolism alter the distribution of PCBs in mice and the magnitude of the partitioning of PCBs from blood into tissues can be approximated using composition-based models.<br>

scholarly journals Amperometric Biosensors Based on Direct Electron Transfer Enzymes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4525
Author(s):  
Franziska Schachinger ◽  
Hucheng Chang ◽  
Stefan Scheiblbrandner ◽  
Roland Ludwig
Keyword(s):  
Electron Transfer ◽  
Electrode Materials ◽  
Direct Electron Transfer ◽  
Accurate Determination ◽  
Direct Electrochemistry ◽  
Product Analysis ◽  
Amperometric Biosensors ◽  
Chemical Surface ◽  
Fusion Enzymes ◽  
Cost Efficient

The accurate determination of analyte concentrations with selective, fast, and robust methods is the key for process control, product analysis, environmental compliance, and medical applications. Enzyme-based biosensors meet these requirements to a high degree and can be operated with simple, cost efficient, and easy to use devices. This review focuses on enzymes capable of direct electron transfer (DET) to electrodes and also the electrode materials which can enable or enhance the DET type bioelectrocatalysis. It presents amperometric biosensors for the quantification of important medical, technical, and environmental analytes and it carves out the requirements for enzymes and electrode materials in DET-based third generation biosensors. This review critically surveys enzymes and biosensors for which DET has been reported. Single- or multi-cofactor enzymes featuring copper centers, hemes, FAD, FMN, or PQQ as prosthetic groups as well as fusion enzymes are presented. Nanomaterials, nanostructured electrodes, chemical surface modifications, and protein immobilization strategies are reviewed for their ability to support direct electrochemistry of enzymes. The combination of both biosensor elements—enzymes and electrodes—is evaluated by comparison of substrate specificity, current density, sensitivity, and the range of detection.

scholarly journals KEMTUB012-NI2, a novel potent tubulysin analog that selectively targets hypoxic cancer cells and is potentiated by cytochrome p450 reductase downregulation

Hypoxia ◽  
2017 ◽  
Vol Volume 5 ◽  
pp. 45-59
Author(s):  
Paolo Lazzari ◽  
Marco Spiga ◽  
Monica Sani ◽  
Matteo Zanda ◽  
Ian N Fleming
Keyword(s):  
Cytochrome P450 ◽  
Cancer Cells ◽  
Cytochrome P450 Reductase ◽  
P450 Reductase

scholarly journals Interaction of human CYP17 (P-45017α, 17α-hydroxylase-17,20-lyase) with cytochrome b5: importance of the orientation of the hydrophobic domain of cytochrome b5

1997 ◽  
Vol 321 (3) ◽  
pp. 857-864 ◽  
Author(s):  
Peter LEE-ROBICHAUD ◽  
Mustak A. KADERBHAI ◽  
Naheed KADERBHAI ◽  
J. Neville WRIGHT ◽  
Muhammad AKHTAR
Keyword(s):  
Signal Sequence ◽  
Cytochrome B5 ◽  
Amino Acid Sequences ◽  
Side Chain ◽  
Hydrophobic Domain ◽  
Side Chain Cleavage ◽  
The Core ◽  
Cleavage Activity ◽  
P450 Reductase ◽  
Chain Cleavage

Human CYP17 (P-45017α, 17α-hydroxylase-17,20-lyase)-catalysed side-chain cleavage of 17α-hydroxyprogestogens into androgens is greatly dependent on the presence of cytochrome b5. The native form of cytochrome b5 is composed of a globular core, residues 1Ő98, followed by a membrane insertable C-terminal tail, residues 99Ő133. In the present study the abilities of five different forms of cytochrome b5 to support the side-chain cleavage activity of CYP17 were compared. The five derivatives were: the native pig cytochrome b5 (native pig), its genetically engineered rat counterpart (coreŐtail), the soluble core form of the latter (core), the core with the secretory signal sequence of alkaline phosphatase appended to its N-terminal (signalŐcore) and the latter containing the C-terminal tail of the native rat protein (signalŐcoreŐtail). When examined by Edman degradation and MS, the engineered proteins were shown to have the expected N-terminal amino acid sequences and molecular masses. The native pig was found to be acetylated at the N-terminal. The native pig and coreŐtail enzymes were equally efficient at enhancing the side-chain cleavage activity of human CYP17 and the signalŐcoreŐtail was 55% as efficient. The core and signalŐcore constructs were completely inactive in the aforementioned reaction. All the five derivatives were reduced to varying degrees by NADPH:cytochrome P-450 (NADPH-P450) reductase and the relative efficiencies of this reduction were reminiscent of the behaviour of these derivatives in supporting the side-chain cleavage reaction. In the side-chain cleavage assay, however, NADPH-P450 reductase was used in large excess so that the reduction of cytochrome b5 derivatives was not rate-limiting. The results highlight that productive interaction between cytochrome b5 and CYP17 is governed not only by the presence of a membrane insertable hydrophobic region on the cytochrome b5 but also by its defined spatial orientation at the C-terminal.

Sign in / Sign up

Export Citation Format

Share Document