De novo design, synthesis, and mechanistic evaluation of short peptides that mimic heat shock protein 27 activity
Jessica Khoa, P. Chi Phama, Suhyeon Kwona, Alana Y. Huang a, Joel P. Riversa, Huixin Wanga, Heath Ecroydb, and W. Alexander Donalda, Shelli R. McAlpine*c ACS Med. Chem. Lett. V12 p713-719 2021 DOI: 10.1021/acsmedchemlett.0c0060
We report the first small molecule peptides based on the N-terminal sequence of Heat shock protein 27 (Hsp27, gene HSPB1) that demonstrates chaperone-like activity. The peptide, comprising of the SWDPF sequence located at Hsp27’s amino (N)-terminal domain, directly regulates protein aggregation events, maintaining the disaggregated state of the model protein, citrate synthase. While traditional inhibitors of protein aggregation act via regulation of a protein that facilitates aggregation or disaggregation, our molecules are the first small peptides between 5-8 amino acids in length, that are based on the N-terminus of Hsp27 and directly control protein aggregation. The presented strategy showcases a new approach for developing small peptides that control protein aggregation in proteins with high aggregate levels, making them a useful approach in developing new drugs.
Using NMR to identify binding regions for N and C-terminal Hsp90 inhibitors using Hsp90 domains
Jeanette R. McConnell, H. Jane Dyson*, Shelli R. McAlpine* RSC Med. Chem. V12, p410-415 2021
Cyclic peptides as drugs for intracellular targets: the next frontier in peptide therapeutic development Laura K. Buckton, Marwa N. Rahimi, and Shelli R. McAlpine* , Chem. Eur. J. V27, p1487-1513 2021 DOI:10.1002/chem.201905385
Real time monitoring of peptide delivery in vitro using high payload pH responsive nanogels Shegufta Farazi, Fan Chen, Henry Foster,Raelene Boquiren, Shelli R. McAlpine and Robert Chapman *Polym. Chem.V11, p425-432 2020, DOI: 10.1039/C9PY01120J
C-terminal Hsp90 inhibitors block the HIF-1 hypoxic response by degrading HIF-1a through the oxygen-dependent degradation pathway Nalin Kataria, Chloe-Anne Martinez, Bernadette Kerr, Samantha S. Zaiter, Monica Morgan, Shelli R. McAlpine and Kristina M Cook* Cell. Physiol. Biochem V53, p480-495 2019 DOI: 10.33594/000000152.
Polymer mediate transport of the Hsp90 inhibitor LB76, a polar resulting cyclic peptide, produces an Hsp90 cellular phenotype Marwa N. Rahimi, Henry G. Foster, Shegufta N. Farazi, Robert Chapman*, and Shelli R. McAlpine* Chem Commun, V55, p4515-4518 2019 DOI:10.1039/C9CC00890J
Delivering bioactive cyclic peptides that target Hsp90 as prodrugs Yuantao Huo, Laura K. Buckton, Jack L. Bennett, Eloise C. Smith, Frances, L. Byrne, Kyle L. Hoehn, Marwa N. Rahimi, and Shelli R. McAlpine* J. Enzyme Inhib. Med. Chem.V34, p728-739, 2019 DOI: 10.1080/14756366.2019.1580276
Protein-protein inhibitors designed de-novo to target the C-terminus of Hsp90 block co-chaperone activity Marwa N. Rahimi and Shelli R. McAlpine* Chem. Commun. V55, p846-849, 2019 DOI: 10.1039/C8CC07576J
Designing de novo small molecules that control Heat shock protein 70 within the chaperone machinery Samantha S. Zaiter, Yuantao Huo, Fong Ying Tiew, Jason E. Gestwicki, and Shelli R. McAlpine* J. Med. Chem. V62, p742-761, 2019 DOI: 10.1021/acs.jmedchem.8b01436
Nanoparticles for bioapplications: Study of the cytotoxicity of water dispersible CdSe(S) and CdSe(S)/ZnO Quantum Dots F Mirnajafizadeh, D. Ramsey, S. R. McAlpine, F. Wang, P. Reece, J. Stride* Nanomaterials, V9 p465 2019 DOI: 10.3390/nano9030465
Functionalization of Quinazolin-4-Ones Part 3: Synthesis, structures,elucidation DNA-PK, PI3K and cytotoxicity of novel 8-aryl-2-morpholino-quinazolin-4-ones Jacob T. Heppella, MD. Amirul Islamc Shelli R McAlpine and Jasim M. A. Al-Rawi* J. Heterocycl. Chem., V56, p124-142 2019 DOI: 10.1002/jhet.3385 2019
Hsp90 mediates membrane deformation and exosome release Elsa Lauwers,* Yu-Chung Wang, Rodrigo Gallardo, Rob Van der Kant, Emiel Michiels, Jef Swerts, Pieter Baatsen, Samantha S. Zaiter, Shelli R. McAlpine, Natalia V. Gounko, Frederic Rousseau, Joost Schymkowitz, and Patrik Verstreken* Molecular Cell V71, p689-702, e9 2018 DOI: 10.1016/j.molcel.2018.07.016
Converting Polar cyclic peptides into cell permeable molecules using N-methylation Leo L. H. Lee, Laura K. Buckton* and Shelli R. McAlpine* Peptide Science, V110, e24063. 2018 DOI: 10.1002/pep2.24063
Improving the cell permeability of polar cyclic peptides by replacing residues with alkylated amino acids, asparagines, and D-amino acids Laura K. Buckton and Shelli R. McAlpine*Org. Lett. V20, p506-509, 2018
Synthesis and structure-activity relationships of inhibitors that target the C-terminal MEEVD on Heat shock protein 90 (Hsp90) Marwa N. Rahimi, Laura K. Buckton, Samantha S. Zaiter, Jessica Kho, Vickie Chan, Aldwin Guo, Jenane Konesan, SuHyeon Kwon, Lok K. O. Lam, Michael F. Lawler, Michael Leong, Gabriel D. Moldovan, David A. Neale, Gillian Thornton, and Shelli R. McAlpine* ACS Med. Chem. Lett. V9 p73-77 2018
RITA mimics: Synthesis and mechanistic evaluation of asymmetric linked Trithiazoles Adrian L. Pietkiewicz,† Yuqi Zhang,† Marwa N. Rahimi, Michael Stramandinoli, Matthew Teusner, and Shelli R. McAlpine* ACS Med. Chem. Lett. V8 p401-406 2017
Redefining the phenotype of Heat shock protein 90 (Hsp90) inhibitors Yao Wang, Yen Chin Koay, and Shelli R. McAlpine*Chem. Eur. J. V23 2010-2013 2017
The phenotypes produced when cells are treated with the Hsp90 inhibitors AUY922 or 17-AAG (classical inhibitors) are different to those produced when cells are knocked down with Hsp90a. Pull-down assays using classical inhibitors suggest that these molecules bind to multiple targets other than Hsp90. Classical inhibitors also induce similar protein markers as other anti-cancer therapies Cisplatin and bortezomib that do not target Hsp90. Together these data suggest that AUY922 and 17-AAG acts on multiple targets and likely kills cells through multiple mechanisms. Comparing these classical inhibitors to the effects seen when treating cells with C-terminal Hsp90 modulators reveals that C-terminal modulators effectively bind to Hsp90, and induce phenotypic markers consistent with the Hsp90a CRISPR knockdown data. Our findings challenge the current interpretation of Hsp90 inhibitors and suggest that a large body of literature that describes the Hsp90 phenotype and inhibitors is re-examined in this context.
How selective are Hsp90 inhibitors for cancer cells over normal cells? Yao Wang, Yen Chin Koay, and Shelli R. McAlpine*ChemMedChem V12 p353-357 2017
Selectively inhibiting target proteins in cancer cells over normal cells is one of the most critical features of a successful protein inhibitor for clinical applications. By evaluating and comparing the impact of a clinical N-terminal heat shock protein 90 (Hsp90) inhibitor, AUY922 (luminespib), on Hsp90 inhibition-associated cellular events in cancer cells versus normal cells, we found that it produces similar phenotype characteristics in both cell types, indicating that AUY922 is not selective for targeting Hsp90 in tumor cells. By comparison, the C-terminal Hsp90 modulator SM258 suppresses cell proliferation, triggers apoptosis, regulates the expression of Hsp90-associated heat shock proteins, and enhances the degradation of Hsp90's client proteins preferentially in cancer cells over normal cells. Our findings support a new paradigm that AUY922 is not tumor selective, whereas SM258 is more selective and likely acts through an Hsp90-dependent mechanism.
Allosteric Modulators of Heat Shock Protein 90 (HSP90) Yen Chin Koay and Shelli R. McAlpine * RSC Drug discovery series: “Allosterism in Drug Discovery” DOI:10.1039/9781782629276, p404-426 2016
Three classes of allosteric inhibitors have been described in this chapter. The first were molecules targeting the ATP binding site at the N-terminus of HSP90 (classical inhibitors), while influencing clients that bind to the middle domain. These molecules are the only ones that have reached clinical trials, but they had significant problems including induction of pro-survival responses and dose-limiting toxicities. Thus, these classical inhibitors are being used as part of dual inhibition regiments in current clinical trials. Data was presented in this chapter to suggest that the poor results are also due to the classical inhibitor’s poor selectivity for HSP90 in a cellular environment. Indeed, knocking down HSP90 in cells produces a phenotype that is distinct from that reported with these classical inhibitors. The second class of molecules described are those that bind to the C-terminus (e.g., Novobiocin and KU-174), which have anti-cancer cellular activity without inducing high levels of HSF-1, HSP70, or HSP27. Although these compounds affected several clients that bound to the middle domain, efforts focused on improving the potency and pharmacokinetics of these molecules for in vivo efficacy.
The third class of compounds described are the SM series; these molecules bind between the N- and middle domains of HSP90 but affect the C-terminus. The SM molecules bind to the flexible charged linker region and stop the N-terminus from rotating, thereby blocking access to the C-terminal MEEVD region. By inhibiting access to the MEEVD region, the SM series blocks all co-chaperones with a TRP domain from binding to HSP90. Downstream effects attributed to blocking these co-chaperones produce a reduction of immunophilins FKBP52, and FKBP51, and hormone receptor levels. These SM molecules are also the first to be proven to target HSP90 in the cell. Specifically, as determined using pulldown assays with tagged variants of the molecules in multiple cell lysates, the compounds selectively pull out HSP90. Evaluating their efficacy in cells treated with siRNA for HSP90 we see
that the compounds are more effective when HSP90 is knocked down and less effective when HSP90 is over-expressed. Finally, cells treated with the SM compounds match the phenotype produced when the HSP90 alpha gene is knocked down. Thus, it is possible that there has not yet been a clinical evaluation of HSP90 inhibitors. However, as with all allosteric modulators, there are significant challenges associated with predicting active structures, and as such new direct C-terminal modulators are currently under evaluation.
Reinventing Hsp90 inhibitors: Blocking C-terminal binding events to Hsp90 using dimerized inhibitors Yen Chin Koay, Hendra Wahyudi, and Shelli R. McAlpine* Chem. Eur. J. V22 p18572-18582 2016
Heat shock protein 90 (Hsp90) is a 90 kDa molecular chaperone that functions as a dimer. It facilitates the folding, assembly and stabilization of more than 400 proteins that are responsible for cancer development and progression. The reliance of the clients on Hsp90 has made it a promising anticancer target. Classical inhibitors that block the binding of ATP to the Hsp90’s N-terminus are highly toxic to cells and, trigger a resistance mechanism within cells. This resistance mechanism comprises of a large increase in the pro-survival heat shock proteins (HSF-1, Hsp70 and Hsp27). Molecules that modulate the C-terminus of Hsp90 are effective at inducing cancer cell death without activating the resistance mechanism. Herein we describe here the design, synthesis and biological binding affinity for a series of dimerized C-terminal Hsp90 modulators. We show that dimers of these C-terminal modulators synergistically inhibit Hsp90 compared to monomers.
A novel class of Hsp90 C-terminal modulators have preclinical efficacy in prostate tumor cells without induction of a heat shock response
Heather K. Armstrong, Yen Chin Koay, Swati Irani, Rajdeep Das, Zeyad D. Nassar, The Australian Prostate Cancer Bio resource, Luke A. Set, Margaret M. Centenera, Shelli R. McAlpine* and Lisa A. Butler* The Prostate V76, p1546-1559 2016
While there is compelling rationale to use heat shock protein 90 (Hsp90) inhibitors for treatment of advanced prostate cancer, agents that target the N-terminal ATP-binding site of Hsp90 have shown little clinical benefit. These N-terminal binding agents induce a heat shock response that activates compensatory HSP chaperones, which is believed to contribute in part to the agents’ lack of efficacy. Here, we describe the functional characterization of two novel agents, SM253 and SM258, that bind the N-middle linker region of Hsp90, resulting in reduced client protein activation and preventing C-terminal co-chaperones and client proteins from binding to Hsp90.SM253 and SM258 exhibit antiproliferative and pro-apoptotic activity in multiple prostate cancer cell lines (LNCaP, 22Rv1and PC-3) at low micromolar concentrations. Unlike the N-terminal inhibitors AUY922 and 17-AAG, these SM agents do not induce expression of Hsp27, Hsp40 or Hsp70, proteins that are characteristic of the heat shock response, in any of the prostate cell lines analyzed. Notably, SM258 significantly reduced proliferation within 2 days in human primary prostate tumors cultured ex vivo, without the significant induction of Hsp70 that was caused by AUY922 in the tissues. Our findings provide the first evidence of efficacy of this class of C-terminal modulators of Hsp90 in human prostate tumors, and indicate that further evaluation of these promising new agents is warranted.
The first report of direct inhibitors that target the C-terminus MEEVD region on heat shock protein 90
Laura K. Buckton, Hendra Wahyudi, and Shelli R. McAlpine* Chem. Commun. V52, p501-504 2016
Sixteen linear and cyclic peptides were designed de novo and synthesised. Protein binding data indicates that three compounds directly block acccess to heat shock protein 90 (hsp90)’s C-terminus. These molecules are valuable tools useful for investigating the impact of inhibiting hsp90 via a novel mechanism.
Hitting a moving target: How does an N-Methyl group impact biological activity? Yen Chin Koay, Nicole L. Richardson, Samantha S. Zaiter, Jessica Kho, Sheena Y. Nguyen, Daniel H. Tran, Ka Wai Lee, Laura K. Buckton, and Shelli R. McAlpine* ChemMedChem. V11, p881-892 2016
Macrocycles have several advantages over small-moleculedrugs when it comes to addressing specific protein–protein interactionsas therapeutic targets. Herein we report the synthesisof seven new cyclic peptide molecules and their biologicalactivity. These macrocycles were designed to understand howmoving an N-methyl moiety around the peptide backbone impactsbiological activity. Because the lead non-methylated structure inhibits the oncogenic regulator heat-shock protein90 (Hsp90), two of the most potent analogues were evaluated for their Hsp90 inhibitory activity. We show that incorporating an N-methyl moiety controls the conformation of the macrocycle, which dramatically impacts cytotoxicity and binding affinity for Hsp90. Thus, the placement of an N-methylated amino acid within a macrocycle generates an unpredictable change to the compound’s conformation and hence biological activity.