Molecular probing of the HPV-16 E6 protein alpha helix binding groove with small molecule inhibitors

Anne Rietz, Dino P. Petrov, Matthew Bartolowits, Marsha DeSmet, V. Jo Davisson, Elliot Androphy

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The human papillomavirus (HPV) HPV E6 protein has emerged as a central oncoprotein in HPV-associated cancers in which sustained expression is required for tumor progression. A majority of the E6 protein interactions within the human proteome use an alpha-helix groove interface for binding. The UBE3A/E6AP HECT domain ubiquitin ligase binds E6 at this helix-groove interface. This enables formation of a trimeric complex with p53, resulting in destruction of this tumor suppressor. While recent x-ray crystal structures are useful, examples of small molecule probes that can modulate protein interactions at this interface are limited. To develop insights useful for potential structure-based design of ligands for HPV E6, a series of 2,6-disubstituted benzopyranones were prepared and tested as competitive antagonists of E6-E6AP helix-groove interactions. These small molecule probes were used in both binding and functional assays to evaluate recognition features of the E6 protein. Evidence for an ionic functional group interaction within the helix groove was implicated by the structure-activity among the highest affinity ligands. The molecular topographies of these protein-ligand interactions were evaluated by comparing the binding and activities of single amino acid E6 mutants with the results of molecular dynamic simulations. A group of arginine residues that form a rim-cap over the E6 helix groove offer compensatory roles in binding and recognition of the small molecule probes. The flexibility and impact on the overall helix-groove shape dictated by these residues offer new insights for structure-based targeting of HPV E6.

Original languageEnglish (US)
Article numbere0149845
JournalPLoS One
Volume11
Issue number2
DOIs
StatePublished - Feb 1 2016

Fingerprint

Human papillomavirus 16
Papillomaviridae
Molecules
probes (equipment)
Ligands
Proteins
proteins
Tumors
neoplasms
Oncogene Proteins
Proteome
Neoplasms
Ligases
Ubiquitin
molecular dynamics
Topography
Functional groups
Arginine
Molecular Dynamics Simulation
Molecular dynamics

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Molecular probing of the HPV-16 E6 protein alpha helix binding groove with small molecule inhibitors. / Rietz, Anne; Petrov, Dino P.; Bartolowits, Matthew; DeSmet, Marsha; Davisson, V. Jo; Androphy, Elliot.

In: PLoS One, Vol. 11, No. 2, e0149845, 01.02.2016.

Research output: Contribution to journalArticle

Rietz, Anne ; Petrov, Dino P. ; Bartolowits, Matthew ; DeSmet, Marsha ; Davisson, V. Jo ; Androphy, Elliot. / Molecular probing of the HPV-16 E6 protein alpha helix binding groove with small molecule inhibitors. In: PLoS One. 2016 ; Vol. 11, No. 2.
@article{35ee1c3f54bd4323942bda0c7d0c3f09,
title = "Molecular probing of the HPV-16 E6 protein alpha helix binding groove with small molecule inhibitors",
abstract = "The human papillomavirus (HPV) HPV E6 protein has emerged as a central oncoprotein in HPV-associated cancers in which sustained expression is required for tumor progression. A majority of the E6 protein interactions within the human proteome use an alpha-helix groove interface for binding. The UBE3A/E6AP HECT domain ubiquitin ligase binds E6 at this helix-groove interface. This enables formation of a trimeric complex with p53, resulting in destruction of this tumor suppressor. While recent x-ray crystal structures are useful, examples of small molecule probes that can modulate protein interactions at this interface are limited. To develop insights useful for potential structure-based design of ligands for HPV E6, a series of 2,6-disubstituted benzopyranones were prepared and tested as competitive antagonists of E6-E6AP helix-groove interactions. These small molecule probes were used in both binding and functional assays to evaluate recognition features of the E6 protein. Evidence for an ionic functional group interaction within the helix groove was implicated by the structure-activity among the highest affinity ligands. The molecular topographies of these protein-ligand interactions were evaluated by comparing the binding and activities of single amino acid E6 mutants with the results of molecular dynamic simulations. A group of arginine residues that form a rim-cap over the E6 helix groove offer compensatory roles in binding and recognition of the small molecule probes. The flexibility and impact on the overall helix-groove shape dictated by these residues offer new insights for structure-based targeting of HPV E6.",
author = "Anne Rietz and Petrov, {Dino P.} and Matthew Bartolowits and Marsha DeSmet and Davisson, {V. Jo} and Elliot Androphy",
year = "2016",
month = "2",
day = "1",
doi = "10.1371/journal.pone.0149845",
language = "English (US)",
volume = "11",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "2",

}

TY - JOUR

T1 - Molecular probing of the HPV-16 E6 protein alpha helix binding groove with small molecule inhibitors

AU - Rietz, Anne

AU - Petrov, Dino P.

AU - Bartolowits, Matthew

AU - DeSmet, Marsha

AU - Davisson, V. Jo

AU - Androphy, Elliot

PY - 2016/2/1

Y1 - 2016/2/1

N2 - The human papillomavirus (HPV) HPV E6 protein has emerged as a central oncoprotein in HPV-associated cancers in which sustained expression is required for tumor progression. A majority of the E6 protein interactions within the human proteome use an alpha-helix groove interface for binding. The UBE3A/E6AP HECT domain ubiquitin ligase binds E6 at this helix-groove interface. This enables formation of a trimeric complex with p53, resulting in destruction of this tumor suppressor. While recent x-ray crystal structures are useful, examples of small molecule probes that can modulate protein interactions at this interface are limited. To develop insights useful for potential structure-based design of ligands for HPV E6, a series of 2,6-disubstituted benzopyranones were prepared and tested as competitive antagonists of E6-E6AP helix-groove interactions. These small molecule probes were used in both binding and functional assays to evaluate recognition features of the E6 protein. Evidence for an ionic functional group interaction within the helix groove was implicated by the structure-activity among the highest affinity ligands. The molecular topographies of these protein-ligand interactions were evaluated by comparing the binding and activities of single amino acid E6 mutants with the results of molecular dynamic simulations. A group of arginine residues that form a rim-cap over the E6 helix groove offer compensatory roles in binding and recognition of the small molecule probes. The flexibility and impact on the overall helix-groove shape dictated by these residues offer new insights for structure-based targeting of HPV E6.

AB - The human papillomavirus (HPV) HPV E6 protein has emerged as a central oncoprotein in HPV-associated cancers in which sustained expression is required for tumor progression. A majority of the E6 protein interactions within the human proteome use an alpha-helix groove interface for binding. The UBE3A/E6AP HECT domain ubiquitin ligase binds E6 at this helix-groove interface. This enables formation of a trimeric complex with p53, resulting in destruction of this tumor suppressor. While recent x-ray crystal structures are useful, examples of small molecule probes that can modulate protein interactions at this interface are limited. To develop insights useful for potential structure-based design of ligands for HPV E6, a series of 2,6-disubstituted benzopyranones were prepared and tested as competitive antagonists of E6-E6AP helix-groove interactions. These small molecule probes were used in both binding and functional assays to evaluate recognition features of the E6 protein. Evidence for an ionic functional group interaction within the helix groove was implicated by the structure-activity among the highest affinity ligands. The molecular topographies of these protein-ligand interactions were evaluated by comparing the binding and activities of single amino acid E6 mutants with the results of molecular dynamic simulations. A group of arginine residues that form a rim-cap over the E6 helix groove offer compensatory roles in binding and recognition of the small molecule probes. The flexibility and impact on the overall helix-groove shape dictated by these residues offer new insights for structure-based targeting of HPV E6.

UR - http://www.scopus.com/inward/record.url?scp=84979072348&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84979072348&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0149845

DO - 10.1371/journal.pone.0149845

M3 - Article

C2 - 26915086

AN - SCOPUS:84979072348

VL - 11

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 2

M1 - e0149845

ER -