Faculty Opinions recommendation of New reactions and products resulting from alternative interactions between the P450 enzyme and redox partners.

Abstract Cytochrome P450 enzymes catalyze the degradation of drugs and xenobiotics, but also catalyze a wide variety of biosynthetic processes, including most steps in steroidogenesis. The catalytic rate of a P450 enzyme is determined in large part by the rate of electron transfer from its redox partners. Type I P450 enzymes, found in mitochondria, receive electrons from reduced nicotinamide adenine dinucleotide (NADPH) via the intermediacy of two proteins—ferredoxin reductase (a flavoprotein) and ferredoxin (an iron/sulfur protein). Type I P450 enzymes include the cholesterol side-chain cleavage enzyme (P450scc), the two isozymes of 11-hydroxylase (P450c11β and P450c11AS), and several vitamin D-metabolizing enzymes. Disorders of these enzymes, but not of the two redox partners, have been described. Type II P450 enzymes, found in the endoplasmic reticulum, receive electrons from NADPH via P450 oxidoreductase (POR), which contains two flavin moieties. Steroidogenic Type II P450 enzymes include 17α-hydroxylase/17,20 lyase (P450c17), 21-hydroxylase (P450c21), and aromatase (P450aro). All P450 enzymes catalyze multiple reactions, but P450c17 appears to be unique in that the ratio of its activities is regulated at a posttranslational level. Three factors can increase the degree of 17,20 lyase activity relative to the 17α-hydroxylase activity by increasing electron flow from POR: a high molar ratio of POR to P450c17, serine phosphorylation of P450c17, and the presence of cytochrome b5, acting as an allosteric factor to promote the interaction of POR with P450c17. POR is required for the activity of all 50 human Type II P450 enzymes, and ablation of the Por gene in mice causes embryonic lethality. Nevertheless, mutation of the human POR gene is compatible with life, causing multiple steroidogenic defects and a skeletal dysplasia called Antley-Bixler syndrome.

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Heterologous redox partners supporting the efficient catalysis of epothilone B biosynthesis by EpoK in Schlegelella brevitalea

Microbial Cell Factories ◽

10.1186/s12934-020-01439-5 ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Junheng Liang ◽

Huimin Wang ◽

Xiaoying Bian ◽

Youming Zhang ◽

Guoping Zhao ◽

...

Keyword(s):

Catalytic Activity ◽

Electron Transport ◽

Cytochrome P450 Enzyme ◽

Whole Cell ◽

Epothilone B ◽

Redox Partners ◽

Conversion Rates ◽

Epothilone A ◽

P450 Enzyme ◽

Whole Cell Biotransformation

Abstract Background Epothilone B is a natural product that stabilizes microtubules, similar to paclitaxel (Taxol); therefore, epothilone B and several derivatives have shown obvious antitumour activities. Some of these products are in clinical trials, and one (ixabepilone, BMS) is already on the market, having been approved by the FDA in 2007. The terminal step in epothilone B biosynthesis is catalysed by the cytochrome P450 enzyme EpoK (CYP167A1), which catalyses the epoxidation of the C12–C13 double bond (in epothilone C and D) to form epothilone A and B, respectively. Although redox partners from different sources support the catalytic activity of EpoK in vitro, the conversion rates are low, and these redox partners are not applied to produce epothilone B in heterologous hosts. Results Schlegelella brevitalea DSM 7029 contains electron transport partners that efficiently support the catalytic activity of EpoK. We screened and identified one ferredoxin, Fdx_0135, by overexpressing putative ferredoxin genes in vivo and identified two ferredoxin reductases, FdR_0130 and FdR_7100, by whole-cell biotransformation of epothilone C to effectively support the catalytic activity of EpoK. In addition, we obtained strain H7029-3, with a high epothilone B yield and found that the proportion of epothilone A + B produced by this strain was 90.93%. Moreover, the whole-cell bioconversion strain 7029-10 was obtained; this strain exhibited an epothilone C conversion rate of 100% in 12 h. Further RT-qPCR experiments were performed to analyse the overexpression levels of the target genes. Gene knock-out experiments showed that the selected ferredoxin (Fdx_0135) and its reductases (FdR_0130 and FdR_7100) might participate in critical physiological processes in DSM 7029. Conclusion Gene overexpression and whole-cell biotransformation were effective methods for identifying the electron transport partners of the P450 enzyme EpoK. In addition, we obtained an epothilone B high-yield strain and developed a robust whole-cell biotransformation system. This strain and system hold promise for the industrial production of epothilone B and its derivatives.

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Faculty Opinions recommendation of New reactions and products resulting from alternative interactions between the P450 enzyme and redox partners.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718276150.793500570 ◽

2014 ◽

Author(s):

Elizabeth Gillam ◽

Yosephine Gumulya

Keyword(s):

Redox Partners ◽

P450 Enzyme

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New Reactions and Products Resulting from Alternative Interactions between the P450 Enzyme and Redox Partners

Journal of the American Chemical Society ◽

10.1021/ja4130302 ◽

2014 ◽

Vol 136 (9) ◽

pp. 3640-3646 ◽

Cited By ~ 42

Author(s):

Wei Zhang ◽

Yi Liu ◽

Jinyong Yan ◽

Shaona Cao ◽

Fali Bai ◽

...

Keyword(s):

Redox Partners ◽

P450 Enzyme

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Faculty Opinions recommendation of EpoK, a cytochrome P450 involved in biosynthesis of the anticancer agents epothilones A and B. Substrate-mediated rescue of a P450 enzyme.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1022857.4618080 ◽

2010 ◽

Author(s):

Elizabeth Gillam

Keyword(s):

Cytochrome P450 ◽

Anticancer Agents ◽

P450 Enzyme

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Faculty Opinions recommendation of EpoK, a cytochrome P450 involved in biosynthesis of the anticancer agents epothilones A and B. Substrate-mediated rescue of a P450 enzyme.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1022857.264639 ◽

2004 ◽

Author(s):

David Cane

Keyword(s):

Cytochrome P450 ◽

Anticancer Agents ◽

P450 Enzyme

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Pharmacokinetic Drug-drug Interaction of Antibiotics Used in Sepsis Care in China

Current Drug Metabolism ◽

10.2174/1389200221666200929115117 ◽

2020 ◽

Vol 21 ◽

Author(s):

Xuan Yu ◽

Zixuan Chu ◽

Jian Li ◽

Rongrong He ◽

Yaya Wang ◽

...

Keyword(s):

Drug Interaction ◽

Drug Interactions ◽

Penicillin G ◽

Literature Mining ◽

Human Pharmacokinetics ◽

P450 Enzyme ◽

Drug Drug Interaction ◽

Pharmacokinetic Drug ◽

Sepsis Care

Background: Many antibiotics have a high potential for having an interaction with drugs, as perpetrator and/or victim, in critically ill patients, and particularly in sepsis patients. Methods: The aim of this review is to summarize the pharmacokinetic drug-drug interaction (DDI) of 45 antibiotics commonly used in sepsis care in China. Literature mining was conducted to obtain human pharmacokinetics/dispositions of the antibiotics, their interactions with drug metabolizing enzymes or transporters, and their associated clinical drug interactions. Potential DDI is indicated by a DDI index > 0.1 for inhibition or a treated-cell/untreated-cell ratio of enzyme activity being > 2 for induction. Results: The literature-mined information on human pharmacokinetics of the identified antibiotics and their potential drug interactions is summarized. Conclusion: Antibiotic-perpetrated drug interactions, involving P450 enzyme inhibition, have been reported for four lipophilic antibacterials (ciprofloxacin, erythromycin, trimethoprim, and trimethoprim-sulfamethoxazole) and three lipophilic antifungals (fluconazole, itraconazole, and voriconazole). In addition, seven hydrophilic antibacterials (ceftriaxone, cefamandole, piperacillin, penicillin G, amikacin, metronidazole, and linezolid) inhibit drug transporters in vitro. Despite no reported clinical PK drug interactions with the transporters, caution is advised in the use of these antibacterials. Eight hydrophilic antibacterials (all β-lactams; meropenem, cefotaxime, cefazolin, piperacillin, ticarcillin, penicillin G, ampicillin, and flucloxacillin), are potential victims of drug interactions due to transporter inhibition. Rifampin is reported to perpetrate drug interactions by inducing CYP3A or inhibiting OATP1B; it is also reported to be a victim of drug interactions, due to the dual inhibition of CYP3A4 and OATP1B by indinavir. In addition, three antifungals (caspofungin, itraconazole, and voriconazole) are reported to be victims of drug interactions because of P450 enzyme induction. Reports for other antibiotics acting as victims in drug interactions are scarce.

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Polymorphisms in alcohol metabolizing genes ADH2 and ADH3 and susceptibility to pancreatitis in alcoholics

International Journal of Bioassays ◽

10.21746/ijbio.2017.03.002 ◽

2017 ◽

Vol 6 (03) ◽

pp. 5297

Author(s):

Vedangi Aaren* ◽

Godi Sudhakar ◽

Girinadh L.R.S.

Keyword(s):

Frequency Distribution ◽

Ethanol Metabolism ◽

Alcoholic Pancreatitis ◽

Cytochrome P450 Enzyme ◽

Increased Risk ◽

Significant Difference ◽

Pcr Rflp ◽

P450 Enzyme ◽

Acute Alcoholic Pancreatitis ◽

Acute And Chronic Pancreatitis

In both developed and developing countries, overuse of alcohol is a considered as the major cause of acute and chronic pancreatitis. Prolonged overconsumption of alcohol for 5–10 years typically precedes the initial attack of acute alcoholic pancreatitis. It is observed that only a minority (around 5%) of alcoholics develop pancreatitis. It is now established that the pancreas has the capacity to metabolize ethanol. Previous studies have shown that there are two major pathways of ethanol metabolism, oxidative and non-oxidative. Oxidative ethanol metabolism involves the conversion of ethanol to acetaldehyde, a reaction that is catalysed by aldehyde dehydrogenase (ADH) with contributions from cytochrome P450 enzyme (CYP2E1) and possibly also catalase. Genetic factors regulating alcohol metabolism could predispose in developing alcoholic pancreatitis (AP). We investigated the association of polymorphisms in ADH enzymes with the alcoholic pancreatitis in North coastal Andhra Pradesh. Patients with alcoholic pancreatitis (AP; n = 100), alcoholic controls (AC; n = 100), and healthy controls (HC; n = 100) were included in the study. Blood samples were collected from the subjects in EDTA coated vials. DNA was extracted and genotyping for ADH2 and ADH3 was done by PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism). The products were analysed by gel electrophoresis. The frequency distribution of ADH3*1/*1 genotype was significantly higher in AP group (54%) compared with AC (35%), and HC (42%), and was found to be associated with increased risk of alcoholic pancreatitis. There was no statistically significant difference between the frequency distribution of ADH3*1/*1, ADH3*1/*2, and ADH3*2/*2 genotypes between AC and HC. There was no statistically significant difference between the frequency distribution of ADH2*1/*1, ADH2*1/*2, and ADH2*2/*2 genotypes in AP compared with AC and HC. This study shows that carriers of ADH3*1/*1 individuals consuming alcohol are at higher risk for alcoholic pancreatitis than those with other genotypes such as ADH3*1/*2 and ADH3*2/*2.

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Sertraline concentrations in pregnant women are steady and the drug transfer to their infants is low

European Journal of Clinical Pharmacology ◽

10.1007/s00228-021-03122-z ◽

2021 ◽

Author(s):

E. Heinonen ◽

M. Blennow ◽

M. Blomdahl-Wetterholm ◽

M. Hovstadius ◽

J. Nasiell ◽

...

Keyword(s):

Cord Blood ◽

Pregnant Women ◽

Plasma Concentrations ◽

Relative Difference ◽

Interindividual Variation ◽

Therapeutic Drug ◽

Cytochrome P450 Enzyme ◽

Second Trimester ◽

P450 Enzyme ◽

Placental Passage

Abstract Purpose Sertraline, a selective serotonin reuptake inhibitor (SSRI), is one of the most commonly used antidepressant during pregnancy. Plasma sertraline concentrations vary markedly between individuals, partly explained by variability in hepatic drug metabolizing cytochrome P450-enzyme activity. Our purpose was to study the variability in the plasma concentrations in pregnant women and the passage to their infants. Method Pregnant women with moderate untreated depression were recruited in 2016–2019 in Stockholm Region and randomized to treatment with sertraline or placebo. All received Internet-based cognitive behavior therapy as non-medical treatment. Sertraline plasma concentrations were measured around pregnancy weeks 21 and 30, at delivery, 1-month postpartum, in cord blood and at 48 h of age in the infant. The clinical course of the infants was followed. Results Nine mothers and 7 infants were included in the analysis. Median dose-adjusted sertraline concentration in second trimester was 0.15(ng/mL) /(mg/day), in third trimester and at delivery 0.19 and 1-month postpartum 0.25, with a 67% relative difference between second trimester and postpartum. The interindividual variation was 10-fold. Median concentrations in the infants were 33% and 25% of their mothers’, measured in cord blood, and infant plasma, respectively. Only mild and transient adverse effects were seen on the infants. Conclusion Placental passage of sertraline to the infant is low. However, the interindividual variation in maternal concentrations during pregnancy is huge, why therapeutic drug monitoring might assist in finding the poor metabolizers at risk for adversity and increase the safety of the treatment. Trial registration The trial was registered at clinicaltrials.gov July 9, 2014 with TRN: NCT02185547.

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