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Wei Y, Jiang H, Li F, Chai C, Xu Y, Xing M, Deng W, Wang H, Zhu Y, Yang S, Yu Y, Wang W, Wei Y, Guo Y, Tian J, Du J, Guo Z, Wang Y, Zhao Q. Extravascular administration of IGF1R antagonists protects against aortic aneurysm in rodent and porcine models. Sci Transl Med 2024; 16:eadh1763. [PMID: 38691618 DOI: 10.1126/scitranslmed.adh1763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/10/2024] [Indexed: 05/03/2024]
Abstract
An abdominal aortic aneurysm (AAA) is a life-threatening cardiovascular disease. We identified plasma insulin-like growth factor 1 (IGF1) as an independent risk factor in patients with AAA by correlating plasma IGF1 with risk. Smooth muscle cell- or fibroblast-specific knockout of Igf1r, the gene encoding the IGF1 receptor (IGF1R), attenuated AAA formation in two mouse models of AAA induced by angiotensin II infusion or CaCl2 treatment. IGF1R was activated in aortic aneurysm samples from human patients and mice with AAA. Systemic administration of IGF1C, a peptide fragment of IGF1, 2 weeks after disease development inhibited AAA progression in mice. Decreased AAA formation was linked to competitive inhibition of IGF1 binding to its receptor by IGF1C and modulation of downstream alpha serine/threonine protein kinase (AKT)/mammalian target of rapamycin signaling. Localized application of an IGF1C-loaded hydrogel was developed to reduce the side effects observed after systemic administration of IGF1C or IGF1R antagonists in the CaCl2-induced AAA mouse model. The inhibitory effect of the IGF1C-loaded hydrogel administered at disease onset on AAA formation was further evaluated in a guinea pig-to-rat xenograft model and in a sheep-to-minipig xenograft model of AAA formation. The therapeutic efficacy of IGF1C for treating AAA was tested through extravascular delivery in the sheep-to-minipig model with AAA established for 2 weeks. Percutaneous injection of the IGF1C-loaded hydrogel around the AAA resulted in improved vessel flow dynamics in the minipig aorta. These findings suggest that extravascular administration of IGF1R antagonists may have translational potential for treating AAA.
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Affiliation(s)
- Yongzhen Wei
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
- The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, State Key Laboratory of Vascular Homeostasis and Remodeling, Health Science Center, Peking University, Beijing 100191, China
| | - Huan Jiang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Fengjuan Li
- Beijing Collaborative Innovation Centre for Cardiovascular Disorders, Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Chao Chai
- Department of Radiology, Tianjin Institute of Imaging Medicine, Tianjin First Central Hospital, School of Medicine, Nankai University, Tianjin 300192, China
| | - Yaping Xu
- Zhengzhou Cardiovascular Hospital and 7th People's Hospital of Zhengzhou, Zhengzhou, China
| | - Mengmeng Xing
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Weiliang Deng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - He Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yuexin Zhu
- Beijing Collaborative Innovation Centre for Cardiovascular Disorders, Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Sen Yang
- Department of Vascular Surgery, Tianjin First Central Hospital, Nankai University, Tianjin 300192, China
| | - Yongquan Yu
- Department of Radiology, Weihai Central Hospital, Weihai 264400, China
| | - Wenming Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yan Wei
- Zhengzhou Cardiovascular Hospital and 7th People's Hospital of Zhengzhou, Zhengzhou, China
| | - Yu Guo
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jinwei Tian
- Department of Cardiology, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Jie Du
- Beijing Collaborative Innovation Centre for Cardiovascular Disorders, Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Zhikun Guo
- Zhengzhou Cardiovascular Hospital and 7th People's Hospital of Zhengzhou, Zhengzhou, China
| | - Yuan Wang
- Beijing Collaborative Innovation Centre for Cardiovascular Disorders, Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China
| | - Qiang Zhao
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
- The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, State Key Laboratory of Vascular Homeostasis and Remodeling, Health Science Center, Peking University, Beijing 100191, China
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Li J, Choi E, Yu H, Bai XC. Structural basis of the activation of type 1 insulin-like growth factor receptor. Nat Commun 2019; 10:4567. [PMID: 31594955 PMCID: PMC6783537 DOI: 10.1038/s41467-019-12564-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/10/2019] [Indexed: 11/09/2022] Open
Abstract
Type 1 insulin-like growth factor receptor (IGF1R) is a receptor tyrosine kinase that regulates cell growth and proliferation, and can be activated by IGF1, IGF2, and insulin. Here, we report the cryo-EM structure of full-length IGF1R–IGF1 complex in the active state. This structure reveals that only one IGF1 molecule binds the Γ-shaped asymmetric IGF1R dimer. The IGF1-binding site is formed by the L1 and CR domains of one IGF1R protomer and the α-CT and FnIII-1 domains of the other. The liganded α-CT forms a rigid beam-like structure with the unliganded α-CT, which hinders the conformational change of the unliganded α-CT required for binding of a second IGF1 molecule. We further identify an L1–FnIII-2 interaction that mediates the dimerization of membrane-proximal domains of IGF1R. This interaction is required for optimal receptor activation. Our study identifies a source of the negative cooperativity in IGF1 binding to IGF1R and reveals the structural basis of IGF1R activation. The activation mechanism of type 1 insulin-like growth factor receptor (IGF1R) is not fully understood. Here, the authors determine the cryo-EM structure of full-length, IGF1-bound IGF1R in the active conformation, providing insights into how IGF1 triggers receptor activation.
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Affiliation(s)
- Jie Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eunhee Choi
- Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Hongtao Yu
- Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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3
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Glidden MD, Yang Y, Smith NA, Phillips NB, Carr K, Wickramasinghe NP, Ismail-Beigi F, Lawrence MC, Smith BJ, Weiss MA. Solution structure of an ultra-stable single-chain insulin analog connects protein dynamics to a novel mechanism of receptor binding. J Biol Chem 2018; 293:69-88. [PMID: 29114034 PMCID: PMC5766920 DOI: 10.1074/jbc.m117.808667] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/12/2017] [Indexed: 12/11/2022] Open
Abstract
Domain-minimized insulin receptors (IRs) have enabled crystallographic analysis of insulin-bound "micro-receptors." In such structures, the C-terminal segment of the insulin B chain inserts between conserved IR domains, unmasking an invariant receptor-binding surface that spans both insulin A and B chains. This "open" conformation not only rationalizes the inactivity of single-chain insulin (SCI) analogs (in which the A and B chains are directly linked), but also suggests that connecting (C) domains of sufficient length will bind the IR. Here, we report the high-resolution solution structure and dynamics of such an active SCI. The hormone's closed-to-open transition is foreshadowed by segmental flexibility in the native state as probed by heteronuclear NMR spectroscopy and multiple conformer simulations of crystallographic protomers as described in the companion article. We propose a model of the SCI's IR-bound state based on molecular-dynamics simulations of a micro-receptor complex. In this model, a loop defined by the SCI's B and C domains encircles the C-terminal segment of the IR α-subunit. This binding mode predicts a conformational transition between an ultra-stable closed state (in the free hormone) and an active open state (on receptor binding). Optimization of this switch within an ultra-stable SCI promises to circumvent insulin's complex global cold chain. The analog's biphasic activity, which serendipitously resembles current premixed formulations of soluble insulin and microcrystalline suspension, may be of particular utility in the developing world.
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Affiliation(s)
- Michael D Glidden
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yanwu Yang
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Nicholas A Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Kelley Carr
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | | | - Faramarz Ismail-Beigi
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106; Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Michael C Lawrence
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Brian J Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106; Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106.
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4
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Hexnerová R, Křížková K, Fábry M, Sieglová I, Kedrová K, Collinsová M, Ullrichová P, Srb P, Williams C, Crump MP, Tošner Z, Jiráček J, Veverka V, Žáková L. Probing Receptor Specificity by Sampling the Conformational Space of the Insulin-like Growth Factor II C-domain. J Biol Chem 2016; 291:21234-21245. [PMID: 27510031 PMCID: PMC5076530 DOI: 10.1074/jbc.m116.741041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Indexed: 01/22/2023] Open
Abstract
Insulin and insulin-like growth factors I and II are closely related protein hormones. Their distinct evolution has resulted in different yet overlapping biological functions with insulin becoming a key regulator of metabolism, whereas insulin-like growth factors (IGF)-I/II are major growth factors. Insulin and IGFs cross-bind with different affinities to closely related insulin receptor isoforms A and B (IR-A and IR-B) and insulin-like growth factor type I receptor (IGF-1R). Identification of structural determinants in IGFs and insulin that trigger their specific signaling pathways is of increasing importance in designing receptor-specific analogs with potential therapeutic applications. Here, we developed a straightforward protocol for production of recombinant IGF-II and prepared six IGF-II analogs with IGF-I-like mutations. All modified molecules exhibit significantly reduced affinity toward IR-A, particularly the analogs with a Pro-Gln insertion in the C-domain. Moreover, one of the analogs has enhanced binding affinity for IGF-1R due to a synergistic effect of the Pro-Gln insertion and S29N point mutation. Consequently, this analog has almost a 10-fold higher IGF-1R/IR-A binding specificity in comparison with native IGF-II. The established IGF-II purification protocol allowed for cost-effective isotope labeling required for a detailed NMR structural characterization of IGF-II analogs that revealed a link between the altered binding behavior of selected analogs and conformational rearrangement of their C-domains.
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Affiliation(s)
- Rozálie Hexnerová
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic, Faculty of Science, Charles University in Prague, Albertov 6, Prague 128 43, Czech Republic
| | - Květoslava Křížková
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic, Faculty of Science, Charles University in Prague, Albertov 6, Prague 128 43, Czech Republic
| | - Milan Fábry
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic, and
| | - Irena Sieglová
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Kateřina Kedrová
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic, Faculty of Science, Charles University in Prague, Albertov 6, Prague 128 43, Czech Republic
| | - Michaela Collinsová
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Pavlína Ullrichová
- Department of Analytical Chemistry, University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic
| | - Pavel Srb
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Christopher Williams
- Department of Organic and Biological Chemistry, School of Chemistry, Cantock's Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Matthew P Crump
- Department of Organic and Biological Chemistry, School of Chemistry, Cantock's Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Zdeněk Tošner
- Faculty of Science, Charles University in Prague, Albertov 6, Prague 128 43, Czech Republic
| | - Jiří Jiráček
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Václav Veverka
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic,
| | - Lenka Žáková
- From the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic,
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5
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Lysine residues of IGF-I are substrates for transglutaminases and modulate downstream IGF-I signalling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3176-3185. [DOI: 10.1016/j.bbamcr.2013.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 01/20/2023]
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6
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Zhang Y, Eigenbrot C, Zhou L, Shia S, Li W, Quan C, Tom J, Moran P, Di Lello P, Skelton NJ, Kong-Beltran M, Peterson A, Kirchhofer D. Identification of a small peptide that inhibits PCSK9 protein binding to the low density lipoprotein receptor. J Biol Chem 2013; 289:942-55. [PMID: 24225950 DOI: 10.1074/jbc.m113.514067] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PCSK9 (proprotein convertase subtilisin/kexin type 9) is a negative regulator of the hepatic LDL receptor, and clinical studies with PCSK9-inhibiting antibodies have demonstrated strong LDL-c-lowering effects. Here we screened phage-displayed peptide libraries and identified the 13-amino acid linear peptide Pep2-8 as the smallest PCSK9 inhibitor with a clearly defined mechanism of inhibition that has been described. Pep2-8 bound to PCSK9 with a KD of 0.7 μm but did not bind to other proprotein convertases. It fully restored LDL receptor surface levels and LDL particle uptake in PCSK9-treated HepG2 cells. The crystal structure of Pep2-8 bound to C-terminally truncated PCSK9 at 1.85 Å resolution showed that the peptide adopted a strand-turn-helix conformation, which is remarkably similar to its solution structure determined by NMR. Consistent with the functional binding site identified by an Ala scan of PCSK9, the structural Pep2-8 contact region of about 400 Å(2) largely overlapped with that contacted by the EGF(A) domain of the LDL receptor, suggesting a competitive inhibition mechanism. Consistent with this, Pep2-8 inhibited LDL receptor and EGF(A) domain binding to PCSK9 with IC50 values of 0.8 and 0.4 μm, respectively. Remarkably, Pep2-8 mimicked secondary structural elements of the EGF(A) domain that interact with PCSK9, notably the β-strand and a discontinuous short α-helix, and it engaged in the same β-sheet hydrogen bonds as EGF(A) does. Although Pep2-8 itself may not be amenable to therapeutic applications, this study demonstrates the feasibility of developing peptidic inhibitors to functionally relevant sites on PCSK9.
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Affiliation(s)
- Yingnan Zhang
- From the Departments of Early Discovery Biochemistry
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Rajapaksha H, Alvino C, McCarthy P, Forbes BE. The insulin-like growth factor mutation database (IGFmdb). Growth Horm IGF Res 2012; 22:158-166. [PMID: 22698731 DOI: 10.1016/j.ghir.2012.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 05/15/2012] [Accepted: 05/20/2012] [Indexed: 02/07/2023]
Abstract
Insulin-like growth factors (IGF-I and IGF-II), and insulin are evolutionarily conserved hormonal regulators of eukaryotic growth and development. Through interactions with their cognate receptors, all three molecules can influence cellular growth, proliferation, differentiation, migration, and survival, as well as metabolic processes. As such, perturbations in signaling by IGFs and insulin are a well-documented cause of altered growth, development and survival during both embryonic and post-natal life. A key approach in understanding how IGFs and insulin elicit their biological effects has been through identifying structural features of the ligands that influence their receptor interactions. Over the years, the study of many hundreds of specifically engineered IGF and insulin analogues has provided a wealth of knowledge about how specific residues of these ligands contribute to ligand:receptor interactions. Some analogues have even provided the basis for designing therapeutic agents for the treatment of IGF and insulin-related diseases. As the list of IGF and insulin analogues continues to grow we find that, while many have been produced and studied, it would be of considerable value to have a central repository from which information about specific analogues and their receptor binding data were readily available in an easily searchable and comparable format. To address this, we have created the "Insulin-like growth factor mutation database" (IGFmdb). The IGFmdb is a web-based curated database of annotated ligand analogues and their receptor binding affinities that can be accessed via http://www.adelaide.edu.au/igfmutation. Currently the IGFmdb contains receptor-binding data for 67 IGF-II analogues that were publicly accessible prior to 2012, as well as 67 IGF-I analogues, including all of those produced and characterised in our laboratory. A small number of these are IGF species homologues. There are also 32 insulin analogues within IGFmdb that were reported within the included IGF analogue studies, representing only a small fraction of existing insulin mutants. Future developments of the IGFmdb will incorporate receptor-binding data for all publicly accessible IGF-I analogues and the data will be expanded to include IGF-binding protein (IGFBP) binding affinities.
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Affiliation(s)
- Harinda Rajapaksha
- Discipline of Biochemistry, School of Molecular and Biomedical Science, University of Adelaide, SA, Australia
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8
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Jenkins RJ, Dotson GD. Dual targeting antibacterial peptide inhibitor of early lipid A biosynthesis. ACS Chem Biol 2012; 7:1170-7. [PMID: 22530734 DOI: 10.1021/cb300094a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UDP-3-O-(R-3-hydroxyacyl)GlcN N-acyltransferase (LpxD) has been shown to be essential to survival of lipid A producing Gram-negative bacteria. In this study, LpxD-binding peptides 12 amino acids in length were identified from a phage-bound random peptide library screen. Three peptides displayed antibacterial activity when expressed intracellularly, one of which (RJPXD33) represented 15% of the total hits. RJPXD33 binds to E. coli LpxD with a K(d) of 6 μM and is competitive with R-3-hydroxymyristoyl-ACP binding. RJPXD33 can be C-terminally fused in vivo with thioredoxin or N-terminally modified in vitro with β-alanyl-fluorescein and maintain LpxD binding. The latter was used to develop an LpxD fluorescent binding assay used to evaluate unlabeled ligands and is amenable to small molecule library screening. Furthermore, RJPXD33 also binds to and inhibits E. coli UDP-N-acetylglucosamine acyltransferase (LpxA) with a K(d) of 20 μM, unearthing the possibility for the development of small molecule, dual-binding LpxA/LpxD inhibitors as novel antimicrobials.
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Affiliation(s)
- Ronald J. Jenkins
- Department of Medicinal Chemistry,
College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Garry D. Dotson
- Department of Medicinal Chemistry,
College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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Prymula K, Sałapa K, Roterman I. "Fuzzy oil drop" model applied to individual small proteins built of 70 amino acids. J Mol Model 2010; 16:1269-82. [PMID: 20084418 DOI: 10.1007/s00894-009-0639-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Accepted: 12/07/2009] [Indexed: 12/25/2022]
Abstract
The proteins composed of short polypeptides (about 70 amino acid residues) representing the following functional groups (according to PDB notation): growth hormones, serine protease inhibitors, antifreeze proteins, chaperones and proteins of unknown function, were selected for structural and functional analysis. Classification based on the distribution of hydrophobicity in terms of deficiency/excess as the measure of structural and functional specificity is presented. The experimentally observed distribution of hydrophobicity in the protein body is compared to the idealized one expressed by a three-dimensional Gauss function. The differences between these two distributions reveal the specificity of structural/functional characteristics of the protein. The residues of hydrophobicity deficiency versus the idealized distribution are assumed to indicate cavities with the potential to bind ligands, while the residues of hydrophobicity excess are interpreted as potentially participating in protein-protein complexation. The distribution of hydrophobicity irregularity seems to be specific for particular structures and functions of proteins. A comparative analysis of such profiles is carried out to identify the potential biological activity of proteins of unknown function.
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Affiliation(s)
- Katarzyna Prymula
- Department of Bioinformatics, Telemedicine Jagiellonian University - Collegium Medicum, Lazarza 16, 31-530, Krakow, Poland
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10
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Kuang Z, Yao S, McNeil KA, Forbes BE, Wallace JC, Norton RS. Insulin-like growth factor-I (IGF-I): solution properties and NMR chemical shift assignments near physiological pH. Growth Horm IGF Res 2009; 19:226-231. [PMID: 19056307 DOI: 10.1016/j.ghir.2008.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Revised: 10/08/2008] [Accepted: 10/17/2008] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Insulin-like growth factor-I (IGF-I) plays important roles in normal growth and development, as well as in disease states, and its structure and function have been studied extensively using nuclear magnetic resonance (NMR) spectroscopy. However, IGF-I typically gives poor quality NMR spectra containing many broad peaks, because of aggregation at the protein concentrations generally required for NMR experiments as well as the internal dynamics of the molecule. The present study was undertaken to determine a reliable set of assignments under more physiological conditions. DESIGN Several reports of chemical shift assignments have been published previously for IGF-I either bound to a ligand or at relatively low pH (approximately 3-4), but there are many contradictions among them, reflecting the poor behaviour of IGF-I. Low pH conditions are also suboptimal for the analysis of interactions between IGF-I and IGF binding proteins (IGFBP) or IGFBP fragments. Spectra were recorded at low concentrations in order to identify conditions of temperature and pH where all peaks could be observed. RESULTS We show that good quality 2D (1)H-(15)N HSQC spectra of (15)N-labelled IGF-I can be obtained at pH 6 and 37 degrees C, much closer to physiological conditions, by using lower IGF-I concentrations (0.05 mM). Surprisingly, at this concentration and temperature, spectra were of better quality at pH 6 than at pH 4, in contrast to previous observations made at millimolar concentrations of IGF-I. We were then also able to assign the chemical shifts of IGF-I at pH 6 and 37 degrees C using 3D heteronuclear spectra recorded on a 0.7 mM (15)N/(13)C-labelled IGF-I sample. CONCLUSION These results provide a valuable resource for future studies of the structure, dynamics, folding, and binding interactions of IGF-I, as well as analogues thereof, by means of NMR spectroscopy.
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Affiliation(s)
- Zhihe Kuang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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11
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Sohma Y, Pentelute B, Whittaker J, Hua QX, Whittaker L, Weiss M, Kent S. Comparative Properties of Insulin-like Growth Factor 1 (IGF-1) and [Gly7D-Ala]IGF-1 Prepared by Total Chemical Synthesis. Angew Chem Int Ed Engl 2008; 47:1102-6. [DOI: 10.1002/anie.200703521] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Sohma Y, Pentelute B, Whittaker J, Hua QX, Whittaker L, Weiss M, Kent S. Comparative Properties of Insulin-like Growth Factor 1 (IGF-1) and [Gly7D-Ala]IGF-1 Prepared by Total Chemical Synthesis. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703521] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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13
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Sidhu SS, Kossiakoff AA. Exploring and designing protein function with restricted diversity. Curr Opin Chem Biol 2007; 11:347-54. [PMID: 17500026 DOI: 10.1016/j.cbpa.2007.05.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 05/02/2007] [Indexed: 11/22/2022]
Abstract
Combinatorial libraries with restricted diversity can be used to rapidly map binding energetics across protein interfaces. Shotgun scanning strategies have been used for alanine scanning and for alternative mutagenesis schemes that provide high-resolution functional views of binding interfaces. In addition, synthetic antibodies have been derived from naïve libraries restricted to a binary code to explore the minimal requirements for molecular recognition. These studies shed light on the underlying principles governing molecular recognition, and provide rapid yet quantitative alternatives to conventional biophysical methods for exploring protein structure and function.
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Affiliation(s)
- Sachdev S Sidhu
- Department of Protein Engineering, Genentech Inc, 1 DNA Way, South San Francisco, CA 94080, USA.
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Robinson SA, Rosenzweig SA. Paradoxical effects of the phage display-derived peptide antagonist IGF-F1-1 on insulin-like growth factor-1 receptor signaling. Biochem Pharmacol 2006; 72:53-61. [PMID: 16684509 DOI: 10.1016/j.bcp.2006.03.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 03/30/2006] [Accepted: 03/30/2006] [Indexed: 10/24/2022]
Abstract
The insulin-like growth factor binding proteins (IGFBPs) represent a unique class of IGF antagonists regulating the bioavailability of the IGFs extracellularly. Accordingly, they represent an important class of proteins for cancer therapeutics and chemoprevention. IGF-F1-1 is a cyclic hexadecapeptide identified by high throughput phage display that binds to the IGFBP-binding domain on IGF-1. It acts as an IGFBP-mimetic, capable of inhibiting IGF-1 binding to the IGFBPs. To further examine the utility of IGF-F1-1 as an IGF-1 antagonist we tested its ability to inhibit IGFBP-2 and IGFBP-3 binding to IGF-1, (125)I-IGF-1 binding to IGF-1Rs and to block IGF-1 induced Akt activation, cell cycle changes and [(3)H]thymidine incorporation in MCF-7 cells. These biological activities were inhibited by treatment with IGFBP-2, wortmannin or the IGF-1R tyrosine kinase inhibitor, NVP-AEW541, but not by IGF-F1-1. Our findings confirm previous studies indicating that IGF-F1-1 is a weak antagonist of IGF-1 binding to the IGFBPs and the IGF-1R and suggest that it does not effectively inhibit downstream events stimulated by IGF-1. We further demonstrated that IGF-F1-1 treatment of MCF-7 cells results in the paradoxical activation of Akt, S-phase transition and [(3)H]thymidine incorporation. These results suggest that IGF-F1-1 is a weak agonist, exhibiting mitogenic actions. IGF-F1-1 may act in conjunction with IGF-1 at the IGF-1R or independently of IGF-1 at the IGF-1R or another receptor.
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Affiliation(s)
- Stephanie A Robinson
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics and Hollings Cancer Center, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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15
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Huang K, Dong J, Phillips NB, Carey PR, Weiss MA. Proinsulin Is Refractory to Protein Fibrillation. J Biol Chem 2005; 280:42345-55. [PMID: 16239223 DOI: 10.1074/jbc.m507110200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin is susceptible to fibrillation, a misfolding process leading to well ordered cross-beta assembly. Protection from fibrillation in beta cells is provided by sequestration of the susceptible monomer within zinc hexamers. We demonstrate that proinsulin is refractory to fibrillation under conditions that promote the rapid fibrillation of zinc-free insulin. Proinsulin fibrils, as probed by Raman microscopy, are nonetheless similar in structure to insulin fibrils. The connecting peptide, although not well ordered in native proinsulin, participates in a fibril-specific beta-sheet. Native insulin and proinsulin exhibit similar free energies of unfolding as inferred from guanidine denaturation studies: relative amyloidogenicities are thus not correlated with global stability. Strikingly, the susceptibility of proinsulin to fibrillation is increased by scission of the connecting peptide at single sites. We thus propose that the connecting peptide constrains a large scale conformational change in the misfolded protein. A tethering mechanism is proposed based on a model of an insulin protofilament derived from electron-microscopic image reconstruction. The proposed relationship between cross-beta assembly and protein topology is supported by studies of single-chain analogs (mini-proinsulin and insulin-like growth factor I) in which foreshortened connecting peptides further retard fibrillation. In addition to its classic function to facilitate disulfide pairing, the connecting peptide may protect beta cells from toxic protein misfolding in the endoplasmic reticulum.
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Affiliation(s)
- Kun Huang
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
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16
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Denley A, Cosgrove LJ, Booker GW, Wallace JC, Forbes BE. Molecular interactions of the IGF system. Cytokine Growth Factor Rev 2005; 16:421-39. [PMID: 15936977 DOI: 10.1016/j.cytogfr.2005.04.004] [Citation(s) in RCA: 291] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The insulin-like growth factor (IGF) system is a complex network of two soluble ligands; several cell surface transmembrane receptors and six soluble high-affinity binding-proteins. The IGF system is essential for normal embryonic and postnatal growth, and plays an important role in the function of a healthy immune system, lymphopoiesis, myogenesis and bone growth among other physiological functions. Deregulation of the IGF system leads to stimulation of cancer cell growth and survival. In order to manipulate the IGF system in the treatment of certain disorders, we must understand the protein-protein interactions at a molecular level. The complex molecular interactions of the ligands and receptors of the IGF system underlie all the biological actions mentioned above and will be the focus of this review.
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Affiliation(s)
- Adam Denley
- School of Molecular and Biomedical Science, The University of Adelaide, SA, Australia
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17
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Denley A, Wang CC, McNeil KA, Walenkamp MJE, van Duyvenvoorde H, Wit JM, Wallace JC, Norton RS, Karperien M, Forbes BE. Structural and functional characteristics of the Val44Met insulin-like growth factor I missense mutation: correlation with effects on growth and development. Mol Endocrinol 2004; 19:711-21. [PMID: 15576456 DOI: 10.1210/me.2004-0409] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We have previously described the phenotype resulting from a missense mutation in the IGF-I gene, which leads to expression of IGF-I with a methionine instead of a valine at position 44 (Val44Met IGF-I). This mutation caused severe growth and mental retardation as well as deafness evident at birth and growth retardation in childhood, but is relatively well tolerated in adulthood. We have conducted a biochemical and structural analysis of Val44Met IGF-I to provide a molecular basis for the phenotype observed. Val44Met IGF-I exhibits a 90-fold decrease in type 1 IGF receptor (IGF-1R) binding compared with wild-type human IGF-I and only poorly stimulates autophosphorylation of the IGF-1R. The ability of Val44Met IGF-I to signal via the extracellular signal-regulated kinase 1/2 and Akt/protein kinase B pathways and to stimulate DNA synthesis is correspondingly poorer. Binding or activation of both insulin receptor isoforms is not detectable even at micromolar concentrations. However, Val44Met IGF-I binds IGF-binding protein-2 (IGFBP-2), IGFBP-3, and IGFBP-6 with equal affinity to IGF-I, suggesting the maintenance of overall structure, particularly in the IGFBP binding domain. Structural analysis by nuclear magnetic resonance confirms retention of near-native structure with only local side-chain disruptions despite the significant loss of function. To our knowledge, our results provide the first structural study of a naturally occurring mutant human IGF-I associated with growth and developmental abnormalities and identifies Val44 as an essential residue involved in the IGF-IGF-1R interaction.
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Affiliation(s)
- Adam Denley
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, 5005 South Australia
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18
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Chuman Y, Uren A, Cahill J, Regan C, Wolf V, Kay BK, Rubin JS. Identification of a peptide binding motif for secreted frizzled-related protein-1. Peptides 2004; 25:1831-8. [PMID: 15501513 DOI: 10.1016/j.peptides.2004.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 07/13/2004] [Indexed: 02/06/2023]
Abstract
Secreted Frizzled-related proteins (sFRPs) bind Wnts and modulate their activity. To identify putative sFRP-1 binding motifs, we screened an M13 phage displayed combinatorial peptide library. A predominant motif, L/V-VDGRW-L/V, was present in approximately 70% of the phage that bound sFRP-1. Use of peptide/alkaline phosphatase chimeras and alanine scanning confirmed that the conserved motif was important for sFRP-1 recognition. The dissociation constant for a peptide/sFRP-1 complex was 3.9 microM. Additional analysis revealed that DGR was the core of the binding motif. Although Wnt proteins lack this sequence, other proteins possessing the DGR motif may function as novel binding partners for sFRP-1.
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Affiliation(s)
- Yoshiro Chuman
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892-4256, USA
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Abstract
Since their initial discovery over 25 years ago as IGF carrier proteins, the insulin-like growth factor binding protein (IGFBP) family has grown to six members, ranging in size from 216 to 289 amino acids. The assumption over the years has been that this family of proteins, having higher affinities for IGF-I and IGF-II than does the IGF-IR, serves to block access of these ligands to the receptor. Although the need for such regulatory proteins is consistent with the constitutive secretion of IGFs from many cell types, it is not surprising that additional functions have begun to be uncovered for these proteins. This review will examine new and old actions of the IGFBPs from a biochemical and cell biological perspective.
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Affiliation(s)
- Steven A Rosenzweig
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29403, USA.
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20
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Arkin MR, Wells JA. Small-molecule inhibitors of protein-protein interactions: progressing towards the dream. Nat Rev Drug Discov 2004; 3:301-17. [PMID: 15060526 DOI: 10.1038/nrd1343] [Citation(s) in RCA: 1212] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michelle R Arkin
- Sunesis Pharmaceuticals, 341 Oyster Point Boulevard, South San Francisco, California 94080, USA.
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21
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Sørensen H, Whittaker L, Hinrichsen J, Groth A, Whittaker J. Mapping of the insulin-like growth factor II binding site of the Type I insulin-like growth factor receptor by alanine scanning mutagenesis. FEBS Lett 2004; 565:19-22. [PMID: 15135045 DOI: 10.1016/j.febslet.2004.03.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 03/09/2004] [Accepted: 03/17/2004] [Indexed: 11/20/2022]
Abstract
The Type I insulin-like growth factor receptor is a physiological receptor for insulin-like growth factor II (IGF-II). To characterize the molecular basis of the receptor's ligand binding properties, we have examined the effects of alanine mutations of residues in the ligand binding site of the receptor on its affinity for IGF-II. The functional epitope for IGF-II comprises residues in the N-terminal L1 domain and residues at the C-terminus of the alpha subunit. Cysteine rich domain residues do not appear to be critical for IGF-II binding.
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Affiliation(s)
- Heidi Sørensen
- Receptor Biology Laboratory, Hagedorn Research Institute, 2820 Gentofte, Denmark
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