The identification of unnatural residues that stabilize polyproline type 2 (PPII) folds can aid in the design of peptidomimetics targeting PPII-binding domains. Here, we examine the impact of peptide backbone N-amination on PPII helix stability and find -aminoglycine (aGly) to be an effective PPII promoter. Further derivatization of an aGly-containing peptide affords '-alkylated analogues with increased helical propensity. Backbone N-amination of glycine represents a convenient approach to stabilize PPII conformation and allows for the diversity-oriented synthesis of optimally constrained folds.
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http://dx.doi.org/10.1021/acs.orglett.3c01502 | DOI Listing |
ACS Phys Chem Au
November 2024
Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010, United States.
Protein dynamics in the unfolded state, in the context of early stage protein folding or intrinsically disordered proteins (IDPs), is not well understood. The discovery of IDPs, and their sequence-dependent dynamics, has led to many computational and experimental investigations regarding the conformational preferences of short oligopeptides and individual amino acid residues in the unfolded state. As proteins consist of sequences of amino acid residues, characterizing the intrinsic conformational preferences of the individual residues in the unfolded state is crucial for understanding the emergent conformations of peptides and proteins.
View Article and Find Full Text PDFCommun Chem
August 2024
Instituto de Química Física "Blas Cabrera" - CSIC, Madrid, Spain.
Hydrogen bond cooperativity (HBC) plays an important role in stabilizing protein assemblies built by α-helices and β-sheets, the most common secondary structures. However, whether HBC exists in other types of protein secondary structures such as polyproline II (PPII) helices remains unexplored. This is intriguing, since PPII systems as assembling blocks are continuously emerging across multiple fields.
View Article and Find Full Text PDFSci Rep
August 2024
Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 64202, USA.
The ATR kinase responds to elevated levels of single-stranded DNA (ssDNA) to activate the G2/M checkpoint, regulate origin utilization, preserve fork stability, and allow DNA repair to ensure genome integrity. The intrinsic replication stress in cancer cells makes this pathway an attractive therapeutic target. The ssDNA that drives ATR signaling is sensed by the ssDNA-binding protein replication protein A (RPA), which acts as a platform for ATRIP recruitment and subsequent ATR activation by TopBP1.
View Article and Find Full Text PDFThe ATR kinase responds to elevated levels of single-stranded DNA (ssDNA) to activate the G2/M checkpoint, regulate origin utilization, preserve fork stability, and allow DNA repair towards ensuring genome integrity. The intrinsic replication stress in cancer cells makes this pathway an attractive therapeutic target. The ssDNA that drives ATR signaling is sensed by the ssDNA-binding protein replication protein A (RPA), which acts as a platform for ATRIP recruitment and subsequent ATR activation by TopBP1.
View Article and Find Full Text PDFChem Commun (Camb)
August 2024
CY Cergy Paris Université, CNRS, BioCIS UMR 8076, 95000 Cergy Pontoise, France.
The development and the use of fluorinated polyproline-type II (PPII) foldamers are still underexplored. Herein, trifluoromethyl pseudoprolines have been incorporated into polyproline backbones without affecting their PPII helicity. The ability of the trifluoromethyl groups to increase hydrophobicity and to act as F NMR probes is demonstrated.
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