Human cytochrome P450 3A7 binding four copies of its native substrate dehydroepiandrosterone 3-sulfate

Liu, Jinghan; Kandel, Sylvie E.; Lampe, Jed N.; Scott, Emily E.

doi:10.1016/j.jbc.2023.104993

Cited by 2 publications

(2 citation statements)

References 56 publications

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“…Alternative explanations, such as protein oligomerization or heterotropic allostery, have been proposed for atypical behavior in some P450 members. However, it is worth emphasizing that the multisubstrate binding phenomena in the cytochrome P450 superfamily have remained a topic of ongoing debate since the 1980s. − In addition to 2site states (two substrates), even 3site (2BDM.pdb, 2Z3U.pdb, and 8SO1.pdb, different from the hereby described 3site state for P450cam) − and higher order states (8SO2.pdb and 8GK3.pdb) , have been proposed; although most of these proposals could not efficiently explain (or not investigated) possible links among the binding modes and underlying functional cooperativity among these. To the best of our knowledge, apart from the one being exemplified by the 3site state reported here for P450cam, no other proposed multisubstrate-bound state has offered a comprehensive explanation for the functions of its corresponding P450.…”

Section: Discussionmentioning

confidence: 99%

3site Multisubstrate-Bound State of Cytochrome P450cam

Sahil,

Singh,

Ghosh

et al. 2023

J. Am. Chem. Soc.

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We identified a multisubstrate-bound state, hereby referred as a 3site state, in cytochrome P450cam via integrating molecular dynamics simulation with nuclear magnetic resonance (NMR) pseudocontact shift measurements. The 3site state is a result of simultaneous binding of three camphor molecules in three locations around P450cam: (a) in a well-established "catalytic" site near heme, (b) in a kink-separated "waiting" site along channel-1, and (c) in a previously reported "allosteric" site at E, F, G, and H helical junctions. These three spatially distinct binding modes in the 3site state mutually communicate with each other via homotropic allostery and act cooperatively to render P450cam functional. The 3site state shows a significantly superior fit with NMR pseudo contact shift (PCS) data with a Q-score of 0.045 than previously known bound states and consists of D251 free of salt-bridges with K178 and R186, rendering the enzyme functionally primed. To date, none of the reported cocomplex of P450cam with its redox partner putidaredoxin (pdx) has been able to match solution NMR data and controversial pdx-induced opening of P450cam's channel-1 remains a matter of recurrent discourse. In this regard, inclusion of pdx to the 3site state is able to perfectly fit the NMR PCS measurement with a Q-score of 0.08 and disfavors the pdx-induced opening of channel-1, reconciling previously unexplained remarkably fast hydroxylation kinetics with a k off of 10.2 s −1 . Together, our findings hint that previous experimental observations may have inadvertently captured the 3site state as an in vitro solution state, instead of the catalytic state alone, and provided a distinct departure from the conventional understanding of cytochrome P450.

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Section: Discussionmentioning

confidence: 99%

3site Multisubstrate-Bound State of Cytochrome P450cam

Sahil,

Singh,

Ghosh

et al. 2023

J. Am. Chem. Soc.

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“…An in silico docking routine was employed in order to structurally elucidate the binding interactions between CYP3A7 and paritaprevir. The recently obtained CYP3A7 crystal structure with the endogenous substrate, DHEA-S, bound (8GK3, Liu et al 2023) was downloaded from the Protein Data Bank using the Fetch function in Chimera v.…”

Section: Determination Of Potential Time-dependent Inhibition (Tdi) W...mentioning

confidence: 99%

HCV Antiviral Drugs Have the Potential to Adversely Perturb the Fetal-Maternal Communication Axis through Inhibition of CYP3A7 DHEA-S Oxidation

Work,

Hackett,

Lampe

2024

Drug Metab Dispos

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The hepatitis C virus (HCV) poses a great risk to pregnant people and their developing fetus, yet no HCV antiviral treatment guidelines have been established. While there has been a substantial increase in the development of HCV antivirals, the effect they have on the developing fetus remains poorly defined. Many of these drugs are metabolized through the cytochrome P450 CYP3A pathway, which is mediated by CYP3A7 in the fetus and developing infant. In this study, we sought to investigate the effect HCV antivirals have on CYP3A7 metabolism, as this CYP enzyme plays a vital role in proper fetal and neonatal development. Of the thirteen HCV antivirals we investigated, eight (~62%) inhibited CYP3A7 metabolic activity by 50% or more at a concentration of 20 µM. Furthermore, paritaprevir, asunaprevir, simeprevir, danoprevir, and glecaprevir all had observed half-maximal inhibitory concentrations between the range of 10-20 µM, which is physiologically relevant in comparison to the K m of DHEA-S oxidation (reported to be between 5 to 20 µM). We also discovered that paritaprevir is a timedependent inhibitor of CYP3A7, which shifts the IC 50 ~2-fold from 11 µM to 5 µM. Upon further characterization, paritaprevir inactivates DHEA-S metabolism by CYP3A7, with K I and K inact values of 4.66 µM and 0.00954 min -1 , respectively. Depending on treatment plan and off-label drug use, HCV treatment could adversely affect the fetal-maternal communication axis by blocking fetal CYP3A7 metabolism of important endogenous hormones.

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Human cytochrome P450 3A7 binding four copies of its native substrate dehydroepiandrosterone 3-sulfate

Cited by 2 publications

References 56 publications

3site Multisubstrate-Bound State of Cytochrome P450cam

3site Multisubstrate-Bound State of Cytochrome P450cam

HCV Antiviral Drugs Have the Potential to Adversely Perturb the Fetal-Maternal Communication Axis through Inhibition of CYP3A7 DHEA-S Oxidation

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