scholarly journals Structural characterization of CYP144A1 – a cytochrome P450 enzyme expressed from alternative transcripts in Mycobacterium tuberculosis

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jude Chenge ◽  
Madeline E. Kavanagh ◽  
Max D. Driscoll ◽  
Kirsty J. McLean ◽  
Douglas B. Young ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Cytochrome P450 ◽  
Structural Characterization ◽  
Cytochrome P450 Enzyme ◽  
Alternative Transcripts ◽  
P450 Enzyme

scholarly journals Characterization of Medicago truncatula (barrel medic) hydroperoxide lyase (CYP74C3), a water-soluble detergent-free cytochrome P450 monomer whose biological activity is defined by monomer–micelle association

2006 ◽  
Vol 395 (3) ◽  
pp. 641-652 ◽  
Author(s):  
Richard K. Hughes ◽  
Eric J. Belfield ◽  
Mylrajan Muthusamay ◽  
Anuja Khan ◽  
Arthur Rowe ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Cytochrome P450 ◽  
Medicago Truncatula ◽  
Water Soluble ◽  
Hydroperoxide Lyase ◽  
Cytochrome P450 Enzyme ◽  
Cytochrome P450 Enzymes ◽  
P450 Enzyme ◽  
Detergent Micelles

We describe the detailed biochemical characterization of CYP74C3 (cytochrome P450 subfamily 74C3), a recombinant plant cytochrome P450 enzyme with HPL (hydroperoxide lyase) activity from Medicago truncatula (barrel medic). Steady-state kinetic parameters, substrate and product specificities, RZ (Reinheitszahl or purity index), molar absorption coefficient, haem content, and new ligands for an HPL are reported. We show on the basis of gel filtration, sedimentation velocity (sedimentation coefficient distribution) and sedimentation equilibrium (molecular mass) analyses that CYP74C3 has low enzyme activity as a detergent-free, water-soluble, monomer. The enzyme activity can be completely restored by re-activation with detergent micelles, but not detergent monomers. Corresponding changes in the spin state equilibrium, and probably co-ordination of the haem iron, are novel for cytochrome P450 enzymes and suggest that detergent micelles have a subtle effect on protein conformation, rather than substrate presentation, which is sufficient to improve substrate binding and catalytic-centre activity by an order of magnitude. The kcat/Km of up to 1.6×108 M−1·s−1 is among the highest recorded, which is remarkable for an enzyme whose reaction mechanism involves the scission of a C–C bond. We carried out both kinetic and biophysical studies to demonstrate that this effect is a result of the formation of a complex between a protein monomer and a single detergent micelle. Association with a detergent micelle rather than oligomeric state represents a new mechanism of activation for membrane-associated cytochrome P450 enzymes. Highly concentrated and monodispersed samples of detergent-free CYP74C3 protein may be well suited for the purposes of crystallization and structural resolution of the first plant cytochrome P450 enzyme.

CYTOCHROME P450: Nature's Most Versatile Biological Catalyst

2005 ◽  
Vol 45 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Minor J. Coon
Keyword(s):  
Cytochrome P450 ◽  
Enzyme System ◽  
Cytochrome P450 Enzyme ◽  
Purification And Characterization ◽  
P450 Enzyme ◽  
Microsomal Membranes ◽  
Cytochrome P450 Enzyme System ◽  
The Individual ◽  
Reaction Cycles

The author describes studies that led to the resolution and reconstitution of the cytochrome P450 enzyme system in microsomal membranes. The review indicates how purification and characterization of the cytochromes led to rigorous evidence for multiple isoforms of the oxygenases with distinct chemical and physical properties and different but somewhat overlapping substrate specificities. Present knowledge of the individual steps in the P450 and reductase reaction cycles is summarized, including evidence for the generation of multiple functional oxidants that may contribute to the exceptional diversity of the reactions catalyzed.

The role of cytochrome P450 enzyme genetic variants in cannabis hyperemesis syndrome—A case report

2021 ◽  
Author(s):  
Maxim Kuzin ◽  
Franziskos Xepapadakos ◽  
Isabel Scharrer ◽  
Marc Augsburger ◽  
Chin‐Bin Eap ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Case Report ◽  
Genetic Variants ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Cannabis Hyperemesis Syndrome

Inter-species comparisons of hepatic cytochrome P450 enzyme levels in male ruminants

2003 ◽  
Vol 77 (10) ◽  
pp. 555-560 ◽  
Author(s):  
Miroslav Machala ◽  
Pavel Soucek ◽  
Jir� Neca ◽  
Robert Ulrich ◽  
Jir� Lamka ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Species Comparisons ◽  
Hepatic Cytochrome

scholarly journals Glutathione S-Transferases and Cytochrome P450 Enzyme Expression in Patients with Intracranial Tumors: Preliminary Report of 55 Patients

2018 ◽  
Vol 28 (1) ◽  
pp. 56-62
Author(s):  
Cahit Kural ◽  
Arzu Kaya Kocdogan ◽  
Gulcin Güler Şimşek ◽  
Serpil Oğuztüzün ◽  
Pınar Kaygın ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Brain Tissue ◽  
Pituitary Adenomas ◽  
Normal Brain ◽  
Cytochrome P450 Enzyme ◽  
Intracranial Tumors ◽  
Glutathione S Transferase ◽  
Normal Brain Tissue ◽  
Tissue Samples ◽  
P450 Enzyme

Objective: Intracranial tumors are one of the most frightening and difficult-to-treat tumor types. In addition to surgery, protocols such as chemotherapy and radiotherapy also take place in the treatment. Glutathione S-transferase (GST) and cytochrome P450 (CYP) enzymes are prominent drug-metabolizing enzymes in the human body. The aim of this study is to show the expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 in different types of brain tumors and compare our results with those in the literature. Subjects and Methods: The expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 was analyzed using immunostaining in 55 patients with intracranial tumors in 2016–2017. For GST and CYP expression in normal brain tissue, samples of a portion of surrounding normal brain tissue as well as a matched far neighbor of tumor tissue were used. The demographic features of the patients were documented and the expression results compared. Results: The mean age of the patients was 46.72 years; 29 patients were female and 26 were male. Fifty-seven specimens were obtained from 55 patients. Among them, meningioma was diagnosed in 12, metastases in 12, glioblastoma in 9, and pituitary adenoma in 5. The highest GSTP1, GSTM1, and CYP­1A1 expressions were observed in pituitary adenomas. The lowest GSTP1 expression was detected in glioblastomas and the lowest CYP1B1 expression in pituitary adenomas. Conclusion: GSTP1 and CYP expression is increased in intracranial tumors. These results should be confirmed with a larger series and different enzyme subtypes.

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