Protein/Protein Interactions in the Human Cytochrome P450 System

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Sarah Danyelle Burris-Hiday ◽  
Emily Elizabeth Scott
Keyword(s):  
Cytochrome P450 ◽  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Cytochrome P450 System ◽  
Human Cytochrome

scholarly journals Heteromeric complex formation between human cytochrome P450 CYP1A1 and heme oxygenase-1

2021 ◽  
Author(s):  
J. Patrick Connick ◽  
James R. Reed ◽  
George F. Cawley ◽  
Wayne L. Backes
Keyword(s):  
Cytochrome P450 ◽  
Complex Formation ◽  
Heme Oxygenase ◽  
Protein Interactions ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Stable Complex ◽  
Heme Oxygenase 1 ◽  
Protein Protein Interactions ◽  
Human Cytochrome

P450 and heme oxygenase-1 (HO-1) receive their necessary electrons by interaction with the NADPH-cytochrome P450 reductase (POR).  As the POR concentration is limiting when compared to P450 and HO-1, they must effectively compete for POR to function.  In addition to these functionally required protein-protein interactions, HO-1 forms homomeric complexes, and several P450s have been shown to form complexes with themselves and with other P450s, raising the question, “How are the HO-1 and P450 systems organized in the endoplasmic reticulum?”  Recently, CYP1A2 was shown to associate with HO-1 affecting the function of both proteins.  The goal of this study was to determine if CYP1A1 formed complexes with HO-1 in a similar manner.  Complex formation among POR, HO-1, and CYP1A1 was measured using bioluminescence resonance energy transfer, with results showing HO-1 and CYP1A1 form a stable complex that was further stabilized in the presence of POR.  The POR•CYP1A1 complex was readily disrupted by the addition of HO-1.  CYP1A1 also was able to affect the POR•HO-1 complex, although the effect was smaller.  This interaction between CYP1A1 and HO-1 also affected function, where the presence of CYP1A1 inhibited HO-1-mediated bilirubin formation by increasing the KmPOR•HO-1 without affecting the Vmaxapp.  In like manner, HO-1 inhibited CYP1A1-mediated 7-ethoxyresorufin dealkylation by increasing the KmPOR•CYP1A1.   Based on mathematical simulation, the results could not be explained by a model where CYP1A1 and HO-1 simply compete for POR, and are consistent with formation of a stable CYP1A1•HO-1 complex that affected the functional characteristics of both moieties.

scholarly journals Exploring the Interactome of Cytochrome P450 2E1 in Human Liver Microsomes with Chemical Cross-Linking Mass Spectrometry

2021 ◽  
Author(s):  
Dmitri R. Davydov ◽  
Bikash Dangi ◽  
Guihua Yue ◽  
Bhagwat Prasad ◽  
Viktor G. Zgoda
Keyword(s):  
Mass Spectrometry ◽  
Cytochrome P450 ◽  
Protein Interactions ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Cross Linking ◽  
Cytochrome P450 2E1 ◽  
Protein Protein Interactions ◽  
Chemical Cross Linking

This study aimed on exploration of the system-wide effects of the alcohol-induced increase in the content of cytochrome P450 2E1 (CYP2E1) in the human liver on drug metabolism. Using membrane incorporation of purified CYP2E1 modified with photoreactive crosslinkers benzophenone-4-maleimide (BPM) and 4-(N-succinimidylcarboxy)benzophenone (BPS), we explored the array of its protein-protein interactions (proteome) in human liver microsomes (HLM) with chemical cross-linking mass spectrometry (CXMS). Exposure of bait-incorporated HLM samples to light was followed by isolation of the His-tagged bait protein and its cross-linked aggregates on Ni-NTA agarose. Analyzing the individual bands of SDS-PAGE slabs of thereby isolated protein with the toolset of untargeted proteomics, we detected the cross-linked dimeric and trimeric complexes of CYP2E1 with other drug-metabolizing enzymes. Among the most extensively cross-linked partners of CYP2E1 are cytochromes P450 2A6, 3A4, 2C9, and 4A11. We also detected the conjugates of CYP2E1 with UDP-glucuronosyltransferases (UGTs) 1A6, 1A9, 2B4, 2B15, and 2B17. These results demonstrate the exploratory power of the proposed CXMS strategy and corroborate the concept of tight functional integration in the human drug-metabolizing ensemble through protein-protein interactions of the constituting enzymes. Of particular interest is the observation of efficient cross-linking of CYP2E1 with CYP4A11. This enzyme plays a central role in the synthesis of vasoactive eicosanoids and its interactions with alcohol-inducible CYP2E1 may shed light on the mechanisms of alcohol-induced hypertension.

scholarly journals Probing membrane enhanced protein–protein interactions in a minimal redox complex of cytochrome-P450 and P450-reductase

2019 ◽  
Vol 55 (41) ◽  
pp. 5777-5780 ◽  
Author(s):  
Mukesh Mahajan ◽  
Thirupathi Ravula ◽  
Elke Prade ◽  
G. M. Anantharamaiah ◽  
Ayyalusamy Ramamoorthy
Keyword(s):  
Cytochrome P450 ◽  
Enzymatic Activity ◽  
Protein Interactions ◽  
Protein Protein Interactions ◽  
P450 Reductase

Investigating the interplay in a minimal redox complex of cytochrome-P450 and its reductase is crucial for understanding cytochrome-P450's enzymatic activity.

scholarly journals Study specificity of isatin interactions with P450 cytochromes

2018 ◽  
Vol 64 (1) ◽  
pp. 61-65 ◽  
Author(s):  
P.V. Ershov ◽  
Yu.V. Mezentsev ◽  
E.O. Yablokov ◽  
L.A. Kalushskiy ◽  
A.V. Florinskaya ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Protein Interactions ◽  
Cytochromes P450 ◽  
Cytochrome B5 ◽  
Direct Interaction ◽  
Protein Protein Interactions ◽  
Living Organisms ◽  
Adrenodoxin Reductase ◽  
Equilibrium Dissociation ◽  
Dissociation Constant Kd

Cytochrome P450-dependent monooxygenase systems exist basically in all living organisms, where they perform various important functions. The coordinated functioning of these systems involves many proteins participating in different protein-protein interactions (PPI). Previously, we have found that the endogenous non-peptide bioregulator isatin (indoledione-2,3), synthesized from indole by means of certain cytochromes P450 (e.g. P450 2E1, P450 2C19, P450 2A6) regulates affinity of some PPI. In this work, an attempt has been undertaken to register a direct interaction of isatin with a set of different proteins related to the functioning of cytochrome P450-dependent monooxygenase: five isoforms of cytochromes P450, two isoforms of cytochrome b5, cytochrome P450 reductase, adrenodoxin, adrenodoxin reductase and ferrochelatase. The study has shown that isatin binds specifically only to cytochromes P450 with high affinity (the equilibrium dissociation constant (Kd) is about 10-8 M).

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