In vitro cytochrome P450 monooxygenase and prostaglandin H-synthase mediated aflatoxin B1 biotransformation in guinea pig tissues: Effects of β-naphthoflavone treatment

1993 ◽  
Vol 67 (6) ◽  
pp. 379-385 ◽  
Author(s):  
Ling Liu ◽  
Kanji Nakatsu ◽  
Thomas E. Massey
Keyword(s):  
Cytochrome P450 ◽  
Guinea Pig ◽  
Aflatoxin B1 ◽  
Cytochrome P450 Monooxygenase ◽  
Prostaglandin H Synthase ◽  
P450 Monooxygenase ◽  
Prostaglandin H

In vitro prostaglandin H synthase- and monooxygenase-mediated binding of aflatoxin B1 to DNA in guinea-pig tissue microsomes

1990 ◽  
Vol 11 (11) ◽  
pp. 1915-1919 ◽  
Author(s):  
Ling Liu ◽  
Jonathan M. Daniels ◽  
Richard K. Stewart ◽  
Thomas E. Massey
Keyword(s):  
Guinea Pig ◽  
Aflatoxin B1 ◽  
Prostaglandin H Synthase ◽  
Prostaglandin H

scholarly journals Role of Cytochrome P450 Monooxygenase in the Bioactivation of Aflatoxin B1

2017 ◽  
Vol 46 (9) ◽  
pp. 1499-1503
Author(s):  
Sureeporn Nualkaew ◽  
Hirun Saelim ◽  
Danai Tiwawech ◽  
Tanate Panrat Imran Parvez ◽  
Amornrat Phongdara
Keyword(s):  
Cytochrome P450 ◽  
Aflatoxin B1 ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase

scholarly journals 3,6-Dichlorosalicylate Catabolism Is Initiated by the DsmABC Cytochrome P450 Monooxygenase System inRhizorhabdus dicambivoransNdbn-20

2017 ◽  
Vol 84 (4) ◽  
Author(s):  
Na Li ◽  
Li Yao ◽  
Qin He ◽  
Jiguo Qiu ◽  
Dan Cheng ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Bioinformatic Analysis ◽  
Heme Iron ◽  
Cytochrome P450 Monooxygenase ◽  
Monooxygenase System ◽  
Catabolic Pathway ◽  
P450 Monooxygenase ◽  
Content Type ◽  
Promising Target

ABSTRACTThe degradation of the herbicide dicamba is initiated by demethylation to form 3,6-dichlorosalicylate (3,6-DCSA) inRhizorhabdusdicambivoransNdbn-20. In the present study, a 3,6-DCSA degradation-deficient mutant, Ndbn-20m, was screened. A cluster,dsmR1DABCEFGR2, was lost in this mutant. The cluster consisted of nine genes, all of which were apparently induced by 3,6-DCSA. DsmA shared 30 to 36% identity with the monooxygenase components of reported three-component cytochrome P450 systems and formed a monophyletic branch in the phylogenetic tree. DsmB and DsmC were most closely related to the reported [2Fe-2S] ferredoxin and ferredoxin reductase, respectively. The disruption ofdsmAin strain Ndbn-20 resulted in inactive 3,6-DCSA degradation. WhendsmABC, but notdsmAalone, was introduced into mutant Ndbn-20m andSphingobium quisquiliarumDC-2 (which is unable to degrade salicylate and its derivatives), they acquired the ability to hydroxylate 3,6-DCSA. Single-crystal X-ray diffraction demonstrated that the DsmABC-catalyzed hydroxylation occurred at the C-5 position of 3,6-DCSA, generating 3,6-dichlorogentisate (3,6-DCGA). In addition, DsmD shared 51% identity with GtdA (a gentisate and 3,6-DCGA 1,2-dioxygenase) fromSphingomonassp. strain RW5. However, unlike GtdA, the purified DsmD catalyzed the cleavage of gentisate and 3-chlorogentisate but not 6-chlorogentisate or 3,6-DCGAin vitro. Based on the bioinformatic analysis and gene function studies, a possible catabolic pathway of dicamba inR. dicambivoransNdbn-20 was proposed.IMPORTANCEDicamba is widely used to control a variety of broadleaf weeds and is a promising target herbicide for the engineering of herbicide-resistant crops. The catabolism of dicamba has thus received increasing attention. Bacteria mineralize dicamba initially via demethylation, generating 3,6-dichlorosalicylate. However, the catabolism of 3,6-dichlorosalicylate remains unknown. In this study, we cloned a gene cluster,dsmR1DABCEFGR2, involved in 3,6-dichlorosalicylate degradation fromR. dicambivoransNdbn-20, demonstrated that the cytochrome P450 monooxygenase system DsmABC was responsible for the 5-hydroxylation of 3,6-dichlorosalicylate, and proposed a dicamba catabolic pathway. This study provides a basis to elucidate the catabolism of dicamba and has benefits for the ecotoxicological study of dicamba. Furthermore, the hydroxylation of salicylate has been previously reported to be catalyzed by single-component flavoprotein or three-component Rieske non-heme iron oxygenase, whereas DsmABC was the only cytochrome P450 monooxygenase system hydroxylating salicylate and its methyl- or chloro-substituted derivatives.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

scholarly journals Cytochrome P450 Monooxygenase-Mediated Metabolic Utilization of Benzo[a]Pyrene by Aspergillus Species

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Erin M. Ostrem Loss ◽  
Mi-Kyung Lee ◽  
Ming-Yueh Wu ◽  
Julia Martien ◽  
Wanping Chen ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Environmental Pollutants ◽  
Energy Generation ◽  
Fungal Species ◽  
Metabolic Changes ◽  
Cytochrome P450 Monooxygenase ◽  
Cellular Growth ◽  
P450 Monooxygenase ◽  
Content Type ◽  
Fundamental Knowledge

ABSTRACT Soil-dwelling fungal species possess the versatile metabolic capability to degrade complex organic compounds that are toxic to humans, yet the mechanisms they employ remain largely unknown. Benzo[a]pyrene (BaP) is a pervasive carcinogenic contaminant, posing a significant concern for human health. Here, we report that several Aspergillus species are capable of degrading BaP. Exposing Aspergillus nidulans cells to BaP results in transcriptomic and metabolic changes associated with cellular growth and energy generation, implying that the fungus utilizes BaP as a growth substrate. Importantly, we identify and characterize the conserved bapA gene encoding a cytochrome P450 monooxygenase that is necessary for the metabolic utilization of BaP in Aspergillus. We further demonstrate that the fungal NF-κB-type velvet regulators VeA and VelB are required for proper expression of bapA in response to nutrient limitation and BaP degradation in A. nidulans. Our study illuminates fundamental knowledge of fungal BaP metabolism and provides novel insights into enhancing bioremediation potential. IMPORTANCE We are increasingly exposed to environmental pollutants, including the carcinogen benzo[a]pyrene (BaP), which has prompted extensive research into human metabolism of toxicants. However, little is known about metabolic mechanisms employed by fungi that are able to use some toxic pollutants as the substrates for growth, leaving innocuous by-products. This study systemically demonstrates that a common soil-dwelling fungus is able to use benzo[a]pyrene as food, which results in expression and metabolic changes associated with growth and energy generation. Importantly, this study reveals key components of the metabolic utilization of BaP, notably a cytochrome P450 monooxygenase and the fungal NF-κB-type transcriptional regulators. Our study advances fundamental knowledge of fungal BaP metabolism and provides novel insight into designing and implementing enhanced bioremediation strategies.

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.

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