scholarly journals Inhibition of phase-1 biotransformation and cytostatic effects of diphenyleneiodonium on hepatoblastoma cell line HepG2 and a CYP3A4-overexpressing HepG2 cell clone

2021 ◽  
pp. 1-13
Author(s):  
Christian Schulz ◽  
Friedrich Jung ◽  
Jan-Heiner Küpper
Keyword(s):  
Cytochrome P450 ◽  
Hepg2 Cell ◽  
Cell Clone ◽  
Recombinant Expression ◽  
Phase 1 ◽  
New Drugs ◽  
Cytochrome P450 Monooxygenases ◽  
Cyp3a4 Activity ◽  
Cell Functions

Cell-based in vitro liver models are an important tool in the development and evaluation of new drugs in pharmacological and toxicological drug assessment. Hepatic microsomal enzyme complexes, consisting of cytochrome P450 oxidoreductase (CPR) and cytochrome P450 monooxygenases (CYPs), play a decisive role in catalysing phase-1 biotransformation of pharmaceuticals and xenobiotics. For a comprehensive understanding of the phase-1 biotransformation of drugs, the availability of well-characterized substances for the targeted modulation of in vitro liver models is essential. In this study, we investigated diphenyleneiodonium (DPI) for its ability to inhibit phase-1 enzyme activity and further its toxicological profile in an in vitro HepG2 cell model with and without recombinant expression of the most important drug metabolization enzyme CYP3A4. Aim of the study was to identify effective DPI concentrations for CPR/CYP activity modulation and potentially associated dose and time dependent hepatotoxic effects. The cells were treated with DPI doses up to 5,000nM (versus vehicle control) for a maximum of 48 h and subsequently examined for CYP3A4 activity as well as various toxicological relevant parameters such as cell morphology, integrity and viability, intracellular ATP level, and proliferation. Concluding, the experiments revealed a time- and concentration-dependent DPI mediated partial and complete inhibition of CYP3A4 activity in CYP3A4 overexpressing HepG2-cells (HepG2-CYP3A4). Other cell functions, including ATP synthesis and consequently the proliferation were negatively affected in both in vitro cell models. Since neither cell integrity nor cell viability were reduced, the effect of DPI in HepG2 can be assessed as cytostatic rather than cytotoxic.

scholarly journals In Silico Structural Modeling and Analysis of Interactions of Tremellomycetes Cytochrome P450 Monooxygenases CYP51s with Substrates and Azoles

2021 ◽  
Vol 22 (15) ◽  
pp. 7811
Author(s):  
Olufunmilayo Olukemi Akapo ◽  
Joanna M. Macnar ◽  
Justyna D. Kryś ◽  
Puleng Rosinah Syed ◽  
Khajamohiddin Syed ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Structural Analysis ◽  
In Silico ◽  
Web Application ◽  
Cytochrome P450 Monooxygenases ◽  
Agglomerative Clustering ◽  
Ligand Complex ◽  
P450 Monooxygenase ◽  
Study Results

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s’ interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.

scholarly journals Identification and characterization of cytochrome P450 1232A24 and 1232F1 from Arthrobacter sp. and their role in the metabolic pathway of papaverine

2019 ◽  
Vol 166 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Jan M Klenk ◽  
Max-Philipp Fischer ◽  
Paulina Dubiel ◽  
Mahima Sharma ◽  
Benjamin Rowlinson ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Metabolic Pathway ◽  
Biochemical Characterization ◽  
Gene Clusters ◽  
Cytochrome P450 Monooxygenases ◽  
Dihydroxyphenylacetic Acid ◽  
Meta Position ◽  
Redox Partners

AbstractCytochrome P450 monooxygenases (P450s) play crucial roles in the cell metabolism and provide an unsurpassed diversity of catalysed reactions. Here, we report the identification and biochemical characterization of two P450s from Arthrobacter sp., a Gram-positive organism known to degrade the opium alkaloid papaverine. Combining phylogenetic and genomic analysis suggested physiological roles for P450s in metabolism and revealed potential gene clusters with redox partners facilitating the reconstitution of the P450 activities in vitro. CYP1232F1 catalyses the para demethylation of 3,4-dimethoxyphenylacetic acid to homovanillic acid while CYP1232A24 continues demethylation to 3,4-dihydroxyphenylacetic acid. Interestingly, the latter enzyme is also able to perform both demethylation steps with preference for the meta position. The crystal structure of CYP1232A24, which shares only 29% identity to previous published structures of P450s helped to rationalize the preferred demethylation specificity for the meta position and also the broader substrate specificity profile. In addition to the detailed characterization of the two P450s using their physiological redox partners, we report the construction of a highly active whole-cell Escherichia coli biocatalyst expressing CYP1232A24, which formed up to 1.77 g l−1 3,4-dihydroxyphenylacetic acid. Our results revealed the P450s’ role in the metabolic pathway of papaverine enabling further investigation and application of these biocatalysts.

Process development for oxidations of hydrophobic compounds applying cytochrome P450 monooxygenases in-vitro

2016 ◽  
Vol 233 ◽  
pp. 143-150 ◽  
Author(s):  
Jan Brummund ◽  
Monika Müller ◽  
Thomas Schmitges ◽  
Iwona Kaluzna ◽  
Daniel Mink ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Process Development ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
Hydrophobic Compounds

scholarly journals CYP101J2, CYP101J3, and CYP101J4, 1,8-Cineole-Hydroxylating Cytochrome P450 Monooxygenases from Sphingobium yanoikuyae Strain B2

2016 ◽  
Vol 82 (22) ◽  
pp. 6507-6517 ◽  
Author(s):  
Birgit Unterweger ◽  
Dieter M. Bulach ◽  
Judith Scoble ◽  
David J. Midgley ◽  
Paul Greenfield ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Amino Acid ◽  
Amino Acid Sequences ◽  
Cytochrome P450 Monooxygenases ◽  
Content Type ◽  
E Coli ◽  
P450 Monooxygenases ◽  
Isolation And Characterization ◽  
Starting Point

ABSTRACTWe report the isolation and characterization of three new cytochrome P450 monooxygenases: CYP101J2, CYP101J3, and CYP101J4. These P450s were derived fromSphingobium yanoikuyaeB2, a strain that was isolated from activated sludge based on its ability to fully mineralize 1,8-cineole. Genome sequencing of this strain in combination with purification of native 1,8-cineole-binding proteins enabled identification of 1,8-cineole-binding P450s. The P450 enzymes were cloned, heterologously expressed (N-terminally His6tagged) inEscherichia coliBL21(DE3), purified, and spectroscopically characterized. Recombinant whole-cell biotransformation inE. colidemonstrated that all three P450s hydroxylate 1,8-cineole using electron transport partners fromE. colito yield a product putatively identified as (1S)-2α-hydroxy-1,8-cineole or (1R)-6α-hydroxy-1,8-cineole. The new P450s belong to the CYP101 family and share 47% and 44% identity with other 1,8-cineole-hydroxylating members found inNovosphingobium aromaticivoransandPseudomonas putida. Compared to P450cin(CYP176A1), a 1,8-cineole-hydroxylating P450 fromCitrobacter braakii, these enzymes share less than 30% amino acid sequence identity and hydroxylate 1,8-cineole in a different orientation. Expansion of the enzyme toolbox for modification of 1,8-cineole creates a starting point for use of hydroxylated derivatives in a range of industrial applications.IMPORTANCECYP101J2, CYP101J3, and CYP101J4 are cytochrome P450 monooxygenases fromS. yanoikuyaeB2 that hydroxylate the monoterpenoid 1,8-cineole. These enzymes not only play an important role in microbial degradation of this plant-based chemical but also provide an interesting route to synthesize oxygenated 1,8-cineole derivatives for applications as natural flavor and fragrance precursors or incorporation into polymers. The P450 cytochromes also provide an interesting basis from which to compare other enzymes with a similar function and expand the CYP101 family. This could eventually provide enough bacterial parental enzymes with similar amino acid sequences to enablein vitroevolution via DNA shuffling.

scholarly journals Potent LpxC Inhibitors with In Vitro Activity against Multidrug-Resistant Pseudomonas aeruginosa

2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Kevin M. Krause ◽  
Cat M. Haglund ◽  
Christy Hebner ◽  
Alisa W. Serio ◽  
Grace Lee ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Lipid A ◽  
Phase 1 ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Therapeutic Window ◽  
Content Type ◽  
Lipid A Biosynthesis ◽  
Essential Enzyme

ABSTRACT New drugs with novel mechanisms of resistance are desperately needed to address both community and nosocomial infections due to Gram-negative bacteria. One such potential target is LpxC, an essential enzyme that catalyzes the first committed step of lipid A biosynthesis. Achaogen conducted an extensive research campaign to discover novel LpxC inhibitors with activity against Pseudomonas aeruginosa. We report here the in vitro antibacterial activity and pharmacodynamics of ACHN-975, the only molecule from these efforts and the first ever LpxC inhibitor to be evaluated in phase 1 clinical trials. In addition, we describe the profiles of three additional LpxC inhibitors that were identified as potential lead molecules. These efforts did not produce an additional development candidate with a sufficiently large therapeutic window and the program was subsequently terminated.

scholarly journals Altered Human CYP3A4 Activity Caused by Antley-Bixler Syndrome-Related Variants of NADPH-Cytochrome P450 Oxidoreductase Measured in a Robust In Vitro System

2012 ◽  
Vol 40 (4) ◽  
pp. 754-760 ◽  
Author(s):  
Daniela Moutinho ◽  
Christopher C. Marohnic ◽  
Satya P. Panda ◽  
José Rueff ◽  
Bettie Sue Masters ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cyp3a4 Activity ◽  
In Vitro System ◽  
P450 Oxidoreductase ◽  
Nadph Cytochrome ◽  
Cytochrome P450 Oxidoreductase

scholarly journals TCR Gene Transfer: MAGE-C2/HLA-A2 and MAGE-A3/HLA-DP4 Epitopes as Melanoma-Specific Immune Targets

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Trudy Straetemans ◽  
Mandy van Brakel ◽  
Sabine van Steenbergen ◽  
Marieke Broertjes ◽  
Joost Drexhage ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Gene Transfer ◽  
Cell Clone ◽  
Cd4 T Cell ◽  
Adoptive Therapy ◽  
Effective Response ◽  
Cell Functions ◽  
T Cell Clone

Adoptive therapy with TCR gene-engineered T cells provides an attractive and feasible treatment option for cancer patients. Further development of TCR gene therapy requires the implementation of T-cell target epitopes that prevent “on-target” reactivity towards healthy tissues and at the same time direct a clinically effective response towards tumor tissues. Candidate epitopes that meet these criteria are MAGE-C2336-344/HLA-A2 (MC2/A2) and MAGE-A3243-258/HLA-DP4 (MA3/DP4). We molecularly characterized TCRαβgenes of an MC2/A2-specific CD8 and MA3/DP4-specific CD4 T-cell clone derived from melanoma patients who responded clinically to MAGE vaccination. We identified MC2/A2 and MA3/DP4-specific TCR-Vα3/Vβ28 and TCR-Vα38/Vβ2 chains and validated these TCRsin vitroupon gene transfer into primary human T cells. The MC2 and MA3 TCR were surface-expressed and mediated CD8 T-cell functions towards melanoma cell lines and CD4 T-cell functions towards dendritic cells, respectively. We intend to start testing these MAGE-specific TCRs in phase I clinical trial.

Effect of 95% Ethanol Khat Extract and Cathinone on in vitro Human Recombinant Cytochrome P450 (CYP) 2C9, CYP2D6, and CYP3A4 Activity

2018 ◽  
Vol 44 (3) ◽  
pp. 423-431
Author(s):  
Sharoen Yu Ming Lim ◽  
Athira Rafhana Binti Azidin ◽  
Yee Tze Ung ◽  
Mustafa Al-Shagga ◽  
Mohammed Abdullah Alshawsh ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cyp3a4 Activity
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