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Groenevelt JM, Corey DJ, Fehl C. Chemical Synthesis and Biological Applications of O-GlcNAcylated Peptides and Proteins. Chembiochem 2021; 22:1854-1870. [PMID: 33450137 DOI: 10.1002/cbic.202000843] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/15/2021] [Indexed: 12/25/2022]
Abstract
All human cells use O-GlcNAc protein modifications (O-linked N-acetylglucosamine) to rapidly adapt to changing nutrient and stress conditions through signaling, epigenetic, and proteostasis mechanisms. A key challenge for biologists in defining precise roles for specific O-GlcNAc sites is synthetic access to homogenous isoforms of O-GlcNAc proteins, a result of the non-genetically templated, transient, and heterogeneous nature of O-GlcNAc modifications. Toward a solution, this review details the state of the art of two strategies for O-GlcNAc protein modification: advances in "bottom-up" O-GlcNAc peptide synthesis and direct "top-down" installation of O-GlcNAc on full proteins. We also describe key applications of synthetic O-GlcNAc peptide and protein tools as therapeutics, biophysical structure-function studies, biomarkers, and as disease mechanistic probes to advance translational O-GlcNAc biology.
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Affiliation(s)
- Jessica M Groenevelt
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - Daniel J Corey
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - Charlie Fehl
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA
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Lee HK, Zhang L, Smith MD, Walewska A, Vellore NA, Baron R, McIntosh JM, White HS, Olivera BM, Bulaj G. A marine analgesic peptide, Contulakin-G, and neurotensin are distinct agonists for neurotensin receptors: uncovering structural determinants of desensitization properties. Front Pharmacol 2015; 6:11. [PMID: 25713532 PMCID: PMC4322620 DOI: 10.3389/fphar.2015.00011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/12/2015] [Indexed: 11/13/2022] Open
Abstract
Neurotensin receptors have been studied as molecular targets for the treatment of pain, schizophrenia, addiction, or cancer. Neurotensin (NT) and Contulakin-G, a glycopeptide isolated from a predatory cone snail Conus geographus, share a sequence similarity at the C-terminus, which is critical for activation of neurotensin receptors. Both peptides are potent analgesics, although affinity and agonist potency of Contulakin-G toward neurotensin receptors are significantly lower, as compared to those for NT. In this work, we show that the weaker agonist properties of Contulakin-G result in inducing significantly less desensitization of neurotensin receptors and preserving their cell-surface density. Structure-activity relationship (SAR) studies suggested that both glycosylation and charged amino acid residues in Contulakin-G or NT played important roles in desensitizing neurotensin receptors. Computational modeling studies of human neurotensin receptor NTS1 and Contulakin-G confirmed the role of glycosylation in weakening interactions with the receptors. Based on available SAR data, we designed, synthesized, and characterized an analog of Contulakin-G in which the glycosylated amino acid residue, Gal-GalNAc-Thr10, was replaced by memantine-Glu10 residue. This analog exhibited comparable agonist potency and weaker desensitization properties as compared to that of Contulakin-G, while producing analgesia in the animal model of acute pain following systemic administration. We discuss our study in the context of feasibility and safety of developing NT therapeutic agents with improved penetration across the blood-brain barrier. Our work supports engineering peptide-based agonists with diverse abilities to desensitize G-protein coupled receptors and further emphasizes opportunities for conotoxins as novel pharmacological tools and drug candidates.
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Affiliation(s)
- Hee-Kyoung Lee
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA
| | - Liuyin Zhang
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA
| | - Misty D Smith
- Department of Pharmacology and Toxicology, University of Utah Salt Lake City, UT, USA
| | - Aleksandra Walewska
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA ; Faculty of Chemistry, University of Gdansk Gdansk, Poland
| | - Nadeem A Vellore
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA
| | - Riccardo Baron
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA
| | - J Michael McIntosh
- Department of Biology, University of Utah Salt Lake City, UT, USA ; Department of Psychiatry, University of Utah Salt Lake City, UT, USA
| | - H Steve White
- Department of Pharmacology and Toxicology, University of Utah Salt Lake City, UT, USA
| | | | - Grzegorz Bulaj
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Research Institute, University of Utah Salt Lake City, UT, USA
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Zhang Y, Muthana SM, Barchi JJ, Gildersleeve JC. Divergent behavior of glycosylated threonine and serine derivatives in solid phase peptide synthesis. Org Lett 2012; 14:3958-61. [PMID: 22817697 PMCID: PMC3417326 DOI: 10.1021/ol301723e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Solid phase peptide coupling of glycosylated threonine derivatives was systematically evaluated. In contrast to glycosylated serine derivatives which are highly prone to epimerization, glycosylated threonine derivatives produce only negligible amounts of epimerization. Under forcing conditions, glycosylated threonine analogs undergo β-elimination, rather than epimerization. Mechanistic studies and molecular modeling were used to understand the origin of the differences in reactivity.
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Affiliation(s)
- Yalong Zhang
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Saddam M. Muthana
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Joseph J. Barchi
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Jeffrey C. Gildersleeve
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
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Zhang Y, Muthana SM, Farnsworth D, Ludek O, Adams K, Barchi JJ, Gildersleeve JC. Enhanced epimerization of glycosylated amino acids during solid-phase peptide synthesis. J Am Chem Soc 2012; 134:6316-25. [PMID: 22390544 PMCID: PMC3324660 DOI: 10.1021/ja212188r] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Glycopeptides are extremely useful for basic research and clinical applications, but access to structurally defined glycopeptides is limited by the difficulties in synthesizing this class of compounds. In this study, we demonstrate that many common peptide coupling conditions used to prepare O-linked glycopeptides result in substantial amounts of epimerization at the α position. In fact, epimerization resulted in up to 80% of the non-natural epimer, indicating that it can be the major product in some reactions. Through a series of mechanistic studies, we demonstrate that the enhanced epimerization relative to nonglycosylated amino acids is due to a combination of factors, including a faster rate of epimerization, an energetic preference for the unnatural epimer over the natural epimer, and a slower overall rate of peptide coupling. In addition, we demonstrate that use of 2,4,6-trimethylpyridine (TMP) as the base in peptide couplings produces glycopeptides with high efficiency and low epimerization. The information and improved reaction conditions will facilitate the preparation of glycopeptides as therapeutic compounds and vaccine antigens.
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Affiliation(s)
- Yalong Zhang
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Saddam M. Muthana
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - David Farnsworth
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Olaf Ludek
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Kristie Adams
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Joseph J. Barchi
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
| | - Jeffrey C. Gildersleeve
- Chemical Biology Laboratory, National Cancer Institute, 376 Boyles Street, Building 376, Frederick, Maryland, 21702
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Lee HK, Zhang L, Smith MD, White HS, Bulaj G. Glycosylated neurotensin analogues exhibit sub-picomolar anticonvulsant potency in a pharmacoresistant model of epilepsy. ChemMedChem 2009; 4:400-5. [PMID: 19173215 DOI: 10.1002/cmdc.200800421] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neurotensin (NT) is an endogenous neuropeptide involved in a variety of central and peripheral neuromodulatory effects. Herein we show the effects of site-specific glycosylation on the in vitro and in vivo pharmacological properties of this neuropeptide. NT analogues containing O-linked disaccharides (beta-melibiose and alpha-TF antigen) or beta-lactose units linked by a PEG(3) spacer were designed and chemically synthesized using Fmoc chemistry. For the latter analogue, Fmoc-Glu-(beta-Lac-PEG(3)-amide) was prepared. Our results indicate that the addition of the disaccharides does not negatively affect the sub-nanomolar affinity or the low-nanomolar agonist potency for the neurotensin receptor subtype 1 (NTS1). Interestingly, three glycosylated analogues exhibited sub-picomolar potency in the 6 Hz limbic seizure mouse model of pharmacoresistant epilepsy following intracerebroventricular administration. Our results suggest for the first time that chemically modified NT analogues may lead to novel antiepileptic therapies.
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Affiliation(s)
- Hee-Kyoung Lee
- Department of Medicinal Chemistry, University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, UT 84112, USA
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