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Identification of a human estrogen receptor α‐derived antiestrogenic peptide that adopts a polyproline II conformation
Author(s) -
Kapitán Josef,
Gallo Dominique,
Goasdoué Nicole,
Nicaise Magali,
Desmadril Michel,
Hecht Lutz,
Leclercq Guy,
Barron Laurence D.,
Jacquot Yves
Publication year - 2009
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.1136
Subject(s) - polyproline helix , chemistry , circular dichroism , peptide , estrogen receptor , receptor , biochemistry , stereochemistry , biology , genetics , cancer , breast cancer
Polyproline II (PPII) helix is an extended secondary structure present in a number of proteins. PPII‐containing sequences mediate specific protein–protein interactions with partners containing appropriate cognate domains called PPII‐recognizing domains (PRDs) and are involved in the activation of intracellular signaling pathways. Thus, the identification of PPII structures in proteins is of great interest, not only to explore molecular and physiological mechanisms, but also to elaborate new potential drugs. By revisiting X‐ray crystal structures of liganded α‐type human estrogen receptor (ERα), we have identified an 11‐residue PPII‐helical sequence (D 321 AEPPILYSEY 331 ) in the ligand‐binding domain of the receptor. The data recorded by far‐ultraviolet circular dichroism (far‐UV CD), vibrational Raman optical activity (ROA) and differential scanning calorimetry (DSC) show that the corresponding peptide (Ac‐DAEPPILYSEY‐NH 2 ) is particularly well structured in PPII, with the same proportion of PPII as observed from X‐ray structures (∼85%). In addition, studies carried out on ERα‐negative Evsa‐T breast cancer cells transiently co‐transfected with a pcDNA3‐ERα plasmid and a Vit‐tk‐Luc reporter gene revealed that the peptide antagonizes the estradiol‐induced transcription providing perspectives for researching new molecules with antagonistic properties. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.