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Stapled peptide

Anaïs F M Noisier, Jesús García, Ioana A Ionuţ, Fernando Albericio
Despite the importance of stapled peptides for drug discovery, only few practical processes to prepare cross-linked peptides have been described; thus the structural diversity of available staple motifs is currently limited. At the same time, C-H activation has emerged as an efficient approach to functionalize complex molecules. Although there are many reports on the C-H functionalization of amino acids, examples of post-synthetic peptide C-H modification are rare and comprise almost only C(sp(2) )-H activation...
November 30, 2016: Angewandte Chemie
Nicholas E Shepherd, Rosemary S Harrison, Gloria Ruiz-Gomez, Giovanni Abbenante, Jody M Mason, David P Fairlie
Bcl2 Homology (BH) proteins can either trigger or prevent programmed cell death or apoptosis. Deregulation of the BH protein family network leads to evasion of apoptosis, uncontrolled proliferation and is a hallmark of cancer. Inhibition of pro-survival BH proteins is a promising chemotherapeutic strategy for certain cancers. We have examined whether helix-constrained peptides based on the BAD BH3 domain (residues 103-127) can be downsized to much smaller more drug-like peptides. We report the preparation, structural characterisation, in vitro Bcl-xL inhibition and leukemic T-cell killing ability of 45 linear, mono-, bi- and tricyclic helical peptidomimetics between 8- and 19-residues in length...
November 7, 2016: Organic & Biomolecular Chemistry
Yana K Rennie, Patrick J McIntyre, Tito Akindele, Richard Bayliss, Andrew G Jamieson
Inhibition of protein kinases using ATP-competitive compounds is an important strategy in drug discovery. In contrast, the allosteric regulation of kinases through the disruption of protein-protein interactions has not been widely adopted, despite the potential for selective targeting. Aurora-A kinase regulates mitotic entry and mitotic spindle assembly, and is a promising target for anti-cancer therapy. The microtubule-associated protein TPX2 activates Aurora-A through binding to two sites. Aurora-A recognition is mediated by two motifs within the first 43 residues of TPX2, connected by a flexible linker...
October 24, 2016: ACS Chemical Biology
Kelly L Keeling, Okki Cho, Denis B Scanlon, Grant W Booker, Andrew D Abell, Kate L Wegener
Constrained α-helical peptides are showing potential as biological probes and therapeutic agents that target protein-protein interactions. However, the factors that determine the optimal constraint locations are still largely unknown. Using the β-integrin/talin protein interaction as a model system, we examine the effect of constraint location on helical conformation, as well as binding affinity, using circular dichroism and NMR spectroscopy. Stapling increased the overall helical content of each integrin-based peptide tested...
October 18, 2016: Organic & Biomolecular Chemistry
F Wachter, A M Morgan, M Godes, R Mourtada, G H Bird, L D Walensky
Hydrocarbon-stapled peptides that display key residues of the p53 transactivation domain have emerged as bona fide clinical candidates for reactivating the tumor suppression function of p53 in cancer by dual targeting of the negative regulators HDM2 and HDMX. A recent study questioned the mechanistic specificity of such stapled peptides based on interrogating their capacity to disrupt p53/HDM2 and p53/HDMX complexes in living cells using a new recombinase enhanced bimolecular luciferase complementation platform (ReBiL)...
October 10, 2016: Oncogene
Andrew M White, David J Craik
Macrocyclic peptides are generally more resistant to proteolysis and often have higher potency than linear peptides and so they are excellent leads in drug design. Their study is significant because they offer potential as a new generation of drugs that are potent and specific, and thus might have fewer side effects than traditional small molecule drugs. Areas covered: This article covers macrocyclic drug leads based on nature-derived cyclic peptides as well as synthetic cyclic peptides and close derivatives...
October 10, 2016: Expert Opinion on Drug Discovery
Joel D Leverson
In this issue of Cell Chemical Biology, Huhn et al. (2016) unveil a clever strategy for selectively and irreversibly inhibiting an anti-apoptotic protein, BFL-1. The authors describe stapled peptides bearing carefully placed electrophiles that target a unique cysteine residue in BFL-1 via covalent modification, thus representing an extension of the stapled peptide concept into the covalent inhibitor space.
September 22, 2016: Cell Chemical Biology
Joshua A Kritzer
No abstract text is available yet for this article.
September 20, 2016: Nature Chemical Biology
Akihito Ochiai, Seiya Tanaka, Takaaki Tanaka, Masayuki Taniguchi
Rice (Oryza sativa) is consumed as a staple food globally, and rice bran, the byproduct, is an unused biomass that is ultimately discarded as waste. Thus, in the present study, a technique for producing tyrosinase inhibitory peptides from rice bran protein (RBP) was developed. Simultaneous treatment of RBP with chymotrypsin and trypsin produced numerous peptides. Subsequently, six tyrosinase inhibitory peptides were isolated from the hydrolysate fractions in a multistep purification protocol, and their amino acid sequences were determined...
September 20, 2016: Journal of Natural Products
Amanda L Edwards, Dimphna H Meijer, Rachel M Guerra, Remco J Molenaar, John A Alberta, Federico Bernal, Gregory H Bird, Charles D Stiles, Loren D Walensky
Basic helix-loop-helix (bHLH) transcription factors play critical roles in organism development and disease by regulating cell proliferation and differentiation. Transcriptional activity, whether by bHLH homo- or heterodimerization, is dependent on protein-protein and protein-DNA interactions mediated by α-helices. Thus, α-helical decoys have been proposed as potential targeted therapies for pathologic bHLH transcription. Here, we developed a library of stabilized α-helices of OLIG2 (SAH-OLIG2) to test the capacity of hydrocarbon-stapled peptides to disrupt OLIG2 homodimerization, which drives the development and chemoresistance of glioblastoma multiforme, one of the deadliest forms of human brain cancer...
October 4, 2016: ACS Chemical Biology
Alessandro Gori, Claudio Peri, Giacomo Quilici, Arnone Nithichanon, Davide Gaudesi, Renato Longhi, Louise Gourlay, Martino Bolognesi, Ganjana Lertmemongkolchai, Giovanna Musco, Giorgio Colombo
Peptides seldom retain stable conformations if separated from their native protein structure. In an immunological context, this potentially affects the development of selective peptide-based bioprobes and, from a vaccine perspective, poses inherent limits in the elicitation of cross-reactive antibodies by candidate epitopes. Here, a 1,4-disubstituted-1,2,3-triazole-mediated stapling strategy was used to stabilize the native α-helical fold of the Pal3 peptidic epitope from the protein antigen PalBp (BPSL2765) from Burkholderia pseudomallei, the etiological agent of melioidosis...
March 11, 2016: ACS Infectious Diseases
Annissa J Huhn, Rachel M Guerra, Edward P Harvey, Gregory H Bird, Loren D Walensky
Anti-apoptotic BCL-2 family proteins block cell death by trapping the critical α-helical BH3 domains of pro-apoptotic members in a surface groove. Cancer cells hijack this survival mechanism by overexpressing a spectrum of anti-apoptotic members, mounting formidable apoptotic blockades that resist chemotherapeutic treatment. Drugging the BH3-binding pockets of anti-apoptotic proteins has become a highest-priority goal, fueled by the clinical success of ABT-199, a selective BCL-2 inhibitor, in reactivating apoptosis in BCL-2-dependent cancers...
September 22, 2016: Cell Chemical Biology
Tracy A Stone, Charles M Deber
Membrane proteins play the central roles in a variety of cellular processes, ranging from nutrient uptake and signalling, to cell-cell communication. Their biological functions are directly related to how they fold and assemble; defects often lead to disease. Protein-protein interactions (PPIs) within the membrane are therefore of great interest as therapeutic targets. Here we review the progress in the application of membrane-insertable peptides for the disruption or stabilization of membrane-based PPIs. We describe the design and preparation of transmembrane peptide mimics; and of several categories of peptidomimetics used for study, including d-enantiomers, non-natural amino acids, peptoids, and β-peptides...
August 28, 2016: Biochimica et Biophysica Acta
Ting-Yi Wang, Jean-Philippe Pellois
Cell-penetrating peptides (CPPs) enter cells primarily by escaping from endosomal compartments or by directly translocating across the plasma membrane. Due to their capability of permeating into the cytosolic space of the cell, CPPs are utilized for the delivery of cell-impermeable molecules. However, the fundamental mechanisms and parameters associated with the penetration of CPPs and their cargos through the lipid bilayer have not been fully determined. This in turn has hampered their usage in biotechnological or therapeutic applications...
July 2016: Communicative & Integrative Biology
Gregory H Bird, Emanuele Mazzola, Kwadwo Opoku-Nsiah, Margaret A Lammert, Marina Godes, Donna S Neuberg, Loren D Walensky
Hydrocarbon-stapled peptides are a class of bioactive alpha-helical ligands developed to dissect and target protein interactions. While there is consensus that stapled peptides can be effective chemical tools for investigating protein regulation, their broader utility for therapeutic modulation of intracellular interactions remains an active area of study. In particular, the design principles for generating cell-permeable stapled peptides are empiric, yet consistent intracellular access is essential to in vivo application...
October 2016: Nature Chemical Biology
Yaw Sing Tan, Judith Reeks, Christopher J Brown, Dawn Thean, Fernando Jose Ferrer Gago, Tsz Ying Yuen, Eunice Tze Leng Goh, Xue Er Cheryl Lee, Claire E Jennings, Thomas L Joseph, Rajamani Lakshminarayanan, David P Lane, Martin E M Noble, Chandra S Verma
Protein flexibility poses a major challenge in binding site identification. Several computational pocket detection methods that utilize small-molecule probes in molecular dynamics (MD) simulations have been developed to address this issue. Although they have proven hugely successful at reproducing experimental structural data, their ability to predict new binding sites that are yet to be identified and characterized has not been demonstrated. Here, we report the use of benzenes as probe molecules in ligand-mapping MD (LMMD) simulations to predict the existence of two novel binding sites on the surface of the oncoprotein MDM2...
September 1, 2016: Journal of Physical Chemistry Letters
Supaluk Tantong, Onanong Pringsulaka, Kamonwan Weerawanich, Arthitaya Meeprasert, Thanyada Rungrotmongkol, Rakrudee Sarnthima, Sittiruk Roytrakul, Supaart Sirikantaramas
Defensins form an antimicrobial peptides (AMP) family, and have been widely studied in various plants because of their considerable inhibitory functions. However, their roles in rice (Oryza sativa L.) have not been characterized, even though rice is one of the most important staple crops that is susceptible to damaging infections. Additionally, a previous study identified 598 rice genes encoding cysteine-rich peptides, suggesting there are several uncharacterized AMPs in rice. We performed in silico gene expression and coexpression network analyses of all genes encoding defensin and defensin-like peptides, and determined that OsDEF7 and OsDEF8 are coexpressed with pathogen-responsive genes...
October 2016: Peptides
Tharindunee Jayakody, Subhi Marwari, Rajamani Lakshminarayanan, Francis Chee Kuan Tan, Charles William Johannes, Brian William Dymock, Anders Poulsen, Deron Raymond Herr, Gavin Stewart Dawe
Relaxin-3 or insulin-like peptide 7 (INSL7) is the most recently discovered relaxin/insulin-like family peptide. Mature relaxin-3 consists of an A chain and a B chain held by disulphide bonds. According to structure activity relationship studies, the relaxin-3 B chain is more important in binding and activating the receptor. RXFP3 (also known as Relaxin-3 receptor 1, GPCR 135, somatostatin- and angiotensin- like peptide receptor or SALPR) was identified as the cognate receptor for relaxin-3 by expression profiles and binding studies...
October 2016: Peptides
Keiko Hojo, Mohammed Akhter Hossain, Julien Tailhades, Fazel Shabanpoor, Lilian L L Wong, Emma E K Ong-Pålsson, Hanna E Kastman, Sherie Ma, Andrew L Gundlach, K Johan Rosengren, John D Wade, Ross A D Bathgate
Structure-activity studies of the insulin superfamily member, relaxin-3, have shown that its G protein-coupled receptor (RXFP3) binding site is contained within its central B-chain α-helix and this helical structure is essential for receptor activation. We sought to develop a single B-chain mimetic that retained agonist activity. This was achieved by use of solid phase peptide synthesis together with on-resin ruthenium-catalyzed ring closure metathesis of a pair of judiciously placed i,i+4 α-methyl, α-alkenyl amino acids...
August 25, 2016: Journal of Medicinal Chemistry
Yong Teng, Haiyan Qin, Abdulaziz Bahassan, N George Bendzunas, Eileen J Kennedy, John K Cowell
Inactivation of the WASF3 gene suppresses invasion and metastasis of breast cancer cells. WASF3 function is regulated through a protein complex that includes the NCKAP1 and CYFIP1 proteins. Here, we report that silencing NCKAP1 destabilizes the WASF3 complex, resulting in a suppression of the invasive capacity of breast, prostate, and colon cancer cells. In an in vivo model of spontaneous metastasis in immunocompromized mice, loss of NCKAP1 also suppresses metastasis. Activation of the WASF protein complex occurs through interaction with RAC1, and inactivation of NCKAP1 prevents the association of RAC1 with the WASF3 complex...
September 1, 2016: Cancer Research
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