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Selicharová I, Fabre B, Soledad Garre Hernández M, Lubos M, Pícha J, Voburka Z, Mitrová K, Jiráček J. Combinatorial Libraries of Bipodal Binders of the Insulin Receptor. ChemMedChem 2024; 19:e202400145. [PMID: 38445366 DOI: 10.1002/cmdc.202400145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 03/07/2024]
Abstract
The binding process of insulin to its transmembrane receptor entails a sophisticated interplay between two proteins, each possessing two binding sites. Given the difficulties associated with the use of insulin in the treatment of diabetes, despite its remarkable efficacy, there is interest in smaller and more stable compounds than the native hormone that would effectively activate the receptor. Our study adopts a strategy focused on synthesizing extensive combinatorial libraries of bipodal compounds consisting of two distinct peptides linked to a molecular scaffold. These constructs, evaluated in a resin bead-bound format, were designed to assess their binding to the insulin receptor. Despite notable nonspecific binding, our approach successfully generated and tested millions of compounds. Rigorous evaluations via flow cytometry and specific antibodies revealed peptide sequences with specific interactions at either receptor binding Site 1 or 2. Notably, these sequences bear similarity to peptides discovered through phage display by other researchers. This convergence of chemical and biological methods underscores nature's beauty, revealing general principles in peptide binding to the insulin receptor. Overall, our study deepens the understanding of molecular interactions in ligand binding to the insulin receptor, highlighting the challenges of targeting large proteins with small synthetic peptides.
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Affiliation(s)
- Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Benjamin Fabre
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - María Soledad Garre Hernández
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Marta Lubos
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Jan Pícha
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Zdeněk Voburka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Katarína Mitrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610, Praha 6, Czech Republic
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2
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An W, Hall C, Li J, Hung A, Wu J, Park J, Wang L, Bai XC, Choi E. Activation of the insulin receptor by insulin-like growth factor 2. Nat Commun 2024; 15:2609. [PMID: 38521788 PMCID: PMC10960814 DOI: 10.1038/s41467-024-46990-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
Insulin receptor (IR) controls growth and metabolism. Insulin-like growth factor 2 (IGF2) has different binding properties on two IR isoforms, mimicking insulin's function. However, the molecular mechanism underlying IGF2-induced IR activation remains unclear. Here, we present cryo-EM structures of full-length human long isoform IR (IR-B) in both the inactive and IGF2-bound active states, and short isoform IR (IR-A) in the IGF2-bound active state. Under saturated IGF2 concentrations, both the IR-A and IR-B adopt predominantly asymmetric conformations with two or three IGF2s bound at site-1 and site-2, which differs from that insulin saturated IR forms an exclusively T-shaped symmetric conformation. IGF2 exhibits a relatively weak binding to IR site-2 compared to insulin, making it less potent in promoting full IR activation. Cell-based experiments validated the functional importance of IGF2 binding to two distinct binding sites in optimal IR signaling and trafficking. In the inactive state, the C-terminus of α-CT of IR-B contacts FnIII-2 domain of the same protomer, hindering its threading into the C-loop of IGF2, thus reducing the association rate of IGF2 with IR-B. Collectively, our studies demonstrate the activation mechanism of IR by IGF2 and reveal the molecular basis underlying the different affinity of IGF2 to IR-A and IR-B.
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Affiliation(s)
- Weidong An
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Catherine Hall
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Jie Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Albert Hung
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Jiayi Wu
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Junhee Park
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Liwei Wang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Eunhee Choi
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.
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Sharma T, Kundu N, Kaur S, Shankaraswamy J, Saxena S. Why to target G-quadruplexes using peptides: Next-generation G4-interacting ligands. J Pept Sci 2023; 29:e3491. [PMID: 37009771 DOI: 10.1002/psc.3491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/04/2023]
Abstract
Guanine-rich oligonucleotides existing in both DNA and RNA are able to fold into four-stranded DNA secondary structures via Hoogsteen type hydrogen-bonding, where four guanines self-assemble into a square planar arrangement, which, when stacked upon each other, results in the formation of higher-order structures called G-quadruplexes. Their distribution is not random; they are more frequently present at telomeres, proto-oncogenic promoters, introns, 5'- and 3'-untranslated regions, stem cell markers, ribosome binding sites and so forth and are associated with various biological functions, all of which play a pivotal role in various incurable diseases like cancer and cellular ageing. Several studies have suggested that G-quadruplexes could not regulate biological processes by themselves; instead, various proteins take part in this regulation and can be important therapeutic targets. There are certain limitations in using whole G4-protein for therapeutics purpose because of its high manufacturing cost, laborious structure prediction, dynamic nature, unavailability for oral administration due to its degradation in the gut and inefficient penetration to reach the target site because of the large size. Hence, biologically active peptides can be the potential candidates for therapeutic intervention instead of the whole G4-protein complex. In this review, we aimed to clarify the biological roles of G4s, how we can identify them throughout the genome via bioinformatics, the proteins interacting with G4s and how G4-interacting peptide molecules may be the potential next-generation ligands for targeting the G4 motifs located in biologically important regions.
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Affiliation(s)
- Taniya Sharma
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Nikita Kundu
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Sarvpreet Kaur
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
| | - Jadala Shankaraswamy
- Department of Fruit Science, College of Horticulture, Mojerla, Sri Konda Laxman Telangana State Horticultural University, Budwel, Telangana, India
| | - Sarika Saxena
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
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4
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Potalitsyn P, Mrázková L, Selicharová I, Tencerová M, Ferenčáková M, Chrudinová M, Turnovská T, Brzozowski AM, Marek A, Kaminský J, Jiráček J, Žáková L. Non-glycosylated IGF2 prohormones are more mitogenic than native IGF2. Commun Biol 2023; 6:863. [PMID: 37598269 PMCID: PMC10439913 DOI: 10.1038/s42003-023-05239-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 08/10/2023] [Indexed: 08/21/2023] Open
Abstract
Insulin-like Growth Factor-2 (IGF2) is important for the regulation of human embryonic growth and development, and for adults' physiology. Incorrect processing of the IGF2 precursor, pro-IGF2(156), leads to the formation of two IGF2 proforms, big-IGF2(87) and big-IGF2(104). Unprocessed and mainly non-glycosylated IGF2 proforms are found at abnormally high levels in certain diseases, but their mode of action is still unclear. Here, we found that pro-IGF2(156) has the lowest ability to form its inactivating complexes with IGF-Binding Proteins and has higher proliferative properties in cells than IGF2 and other IGF prohormones. We also showed that big-IGF2(104) has a seven-fold higher binding affinity for the IGF2 receptor than IGF2, and that pro-IGF2(87) binds and activates specific receptors and stimulates cell growth similarly to the mature IGF2. The properties of these pro-IGF2 forms, especially of pro-IGF2(156) and big-IGF2(104), indicate them as hormones that may be associated with human diseases related to the accumulation of IGF-2 proforms in the circulation.
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Affiliation(s)
- Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12800, Prague 2, Czech Republic
| | - Lucie Mrázková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, 12800, Prague 2, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Michaela Tencerová
- Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, Prague 4, Czech Republic
| | - Michaela Ferenčáková
- Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, Prague 4, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Tereza Turnovská
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Andrzej Marek Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic.
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic.
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5
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Lin J, Selicharová I, Mitrová K, Fabre B, Miriyala VM, Lepšík M, Jiráček J, Hernández MSG. Targeting the insulin receptor with hormone and peptide dimers. J Pept Sci 2023; 29:e3461. [PMID: 36336650 DOI: 10.1002/psc.3461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/24/2022] [Accepted: 10/31/2022] [Indexed: 11/09/2022]
Abstract
Insulin is a key hormone involved in the regulation of overall energetic homeostasis of the organism. The dimeric character of the receptor for insulin evokes ideas about its activation or inhibition with peptide dimers that could either trigger or block the structural transition of the insulin receptor, leading to its activation. Herewith, we present the chemical engineering and biological characterization of several series of insulin dimers or dimers of specific peptides that should be able to bind receptors for insulin or insulin growth factor 1. The hormones or peptides in the dimers were interconnected with different linkers, consisting of triazole moieties and 3, 6, 8, 11, or 23 polyethylene glycol units. The prepared dimers were weaker in binding to insulin receptors than human insulin. However, some of the insulin dimers showed preferential binding specificity toward the isoform A of the insulin receptor, and the insulin dimers also stimulated the insulin receptor more strongly than would be consistent with their binding affinities. Our results suggest that designing insulin dimers may be a promising strategy for modulating the ability of the hormone to activate the receptor or to alter its specificity toward insulin receptor isoforms.
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Affiliation(s)
- Jingjing Lin
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Katarína Mitrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Benjamin Fabre
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Vijay Madhav Miriyala
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.,Regional Center of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
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6
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Jiráček J, Selicharová I, Žáková L. Mutations at hypothetical binding site 2 in insulin and insulin-like growth factors 1 and 2. VITAMINS AND HORMONES 2023; 123:187-230. [PMID: 37717985 DOI: 10.1016/bs.vh.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Elucidating how insulin and the related insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) bind to their cellular receptors (IR and IGF-1R) and how the receptors are activated has been the holy grail for generations of scientists. However, deciphering the 3D structure of tyrosine kinase receptors and their hormone-bound complexes has been complicated by the flexible and dimeric nature of the receptors and the dynamic nature of their interaction with hormones. Therefore, mutagenesis of hormones and kinetic studies first became an important tool for studying receptor interactions. It was suggested that hormones could bind to receptors through two binding sites on the hormone surface called site 1 and site 2. A breakthrough in knowledge came with the solution of cryoelectron microscopy (cryoEM) structures of hormone-receptor complexes. In this chapter, we document in detail the mutagenesis of insulin, IGF-1, and IGF-2 with emphasis on modifications of the hypothetical binding site 2 in the hormones, and we discuss the results of structure-activity studies in light of recent cryoEM structures of hormone complexes with IR and IGF-1R.
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Affiliation(s)
- Jiří Jiráček
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic.
| | - Irena Selicharová
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Žáková
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
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7
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Lin J, Asai S, Selicharová I, Mitrová K, Kaminský J, Young E, Jiráček J. Recombinant Insulin-Like Growth Factor 1 Dimers: Receptor Binding Affinities and Activation Abilities. Int J Pept Res Ther 2023; 29:33. [PMID: 36891560 PMCID: PMC9985566 DOI: 10.1007/s10989-023-10499-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2023] [Indexed: 03/07/2023]
Abstract
Insulin-like growth factor 1 (IGF-1) and its IGF-1 receptor (IGF-1R) belong to an important biological system that is involved in the regulation of normal growth, but that has also been recognized as playing a role in cancer. IGF-1R antagonists could be interesting for the testing of their potential antiproliferative properties as an alternative to IGF-1R tyrosine-kinase inhibitors or anti-IGF-1R monoclonal antibodies. In this study, we were inspired by the successful development of insulin dimers capable of antagonizing insulin effects on the insulin receptor (IR) by simultaneous binding to two separated binding sites and by blocking structural rearrangement of the IR. We designed and produced in Escherichia coli three different IGF-1 dimers in which IGF-1 monomers are interlinked through their N- and C-termini, with linkers having 8, 15 or 25 amino acids. We found that the recombinant products were susceptible to the formation of misfolded or reduced variants, but that some of them were able to bind IGF-1R in low nanomolar affinities and all of them activate IGF-1R proportionally to their binding affinities. Overall, our work can be considered as a pilot study that, although it did not lead to the discovery of new IGF-1R antagonists, explored the possibility of recombinant production of IGF-1 dimers and led to the preparation of active compounds. This work could inspire further studies dealing, for example, with the preparation of IGF-1 conjugates with specific proteins for the study of the hormone and its receptor or for therapeutic applications. Graphical Abstract Supplementary Information The online version contains supplementary material available at 10.1007/s10989-023-10499-1.
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Affiliation(s)
- Jingjing Lin
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Seiya Asai
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Katarína Mitrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Elinor Young
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
- Present Address: Department of Biology, University of York, Wentworth Way, York, YO10 5DD UK
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
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8
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Zhu Y, Chen L, Song B, Cui Z, Chen G, Yu Z, Song B. Insulin-like Growth Factor-2 (IGF-2) in Fibrosis. Biomolecules 2022; 12:1557. [PMID: 36358907 PMCID: PMC9687531 DOI: 10.3390/biom12111557] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 08/27/2023] Open
Abstract
The insulin family consists of insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor 2 (IGF-2), their receptors (IR, IGF-1R and IGF-2R), and their binding proteins. All three ligands are involved in cell proliferation, apoptosis, protein synthesis and metabolism due to their homologous sequences and structural similarities. Insulin-like growth factor 2, a member of the insulin family, plays an important role in embryonic development, metabolic disorders, and tumorigenesis by combining with three receptors with different degrees of affinity. The main pathological feature of various fibrotic diseases is the excessive deposition of extracellular matrix (ECM) after tissue and organ damage, which eventually results in organic dysfunction because scar formation replaces tissue parenchyma. As a mitogenic factor, IGF-2 is overexpressed in many fibrotic diseases. It can promote the proliferation of fibroblasts significantly, as well as the production of ECM in a time- and dose-dependent manner. This review aims to describe the expression changes and fibrosis-promoting effects of IGF-2 in the skin, oral cavity, heart, lung, liver, and kidney fibrotic tissues.
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Affiliation(s)
| | | | | | | | | | - Zhou Yu
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032, China
| | - Baoqiang Song
- Department of Plastic and Reconstructive Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032, China
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9
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Determinants of IGF-II influencing stability, receptor binding and activation. Sci Rep 2022; 12:4695. [PMID: 35304516 PMCID: PMC8933565 DOI: 10.1038/s41598-022-08467-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/28/2022] [Indexed: 11/28/2022] Open
Abstract
Insulin like growth factor II (IGF-II) is involved in metabolic and mitogenic signalling in mammalian cells and plays important roles in normal fetal development and postnatal growth. It is structurally similar to insulin and binds not only with high affinity to the type 1 insulin-like growth factor receptor (IGF-1R) but also to the insulin receptor isoform A (IR-A). As IGF-II expression is commonly upregulated in cancer and its signalling promotes cancer cell survival, an antagonist that blocks IGF-II action without perturbing insulin signalling would be invaluable. The high degree of structural homology between the IR and IGF-1R makes selectively targeting either receptor in the treatment of IGF-II-dependent cancers very challenging. However, there are sequence differences between insulin and IGF-II that convey receptor selectivity and influence binding affinity and signalling outcome. Insulin residue YB16 is a key residue involved in maintaining insulin stability, dimer formation and IR binding. Mutation of this residue to glutamine (as found in IGF-II) results in reduced binding affinity. In this study we sought to determine if the equivalent residue Q18 in IGF-II plays a similar role. We show through site-directed mutagenesis of Q18 that this residue contributes to IGF-II structural integrity, selectivity of IGF-1R/IR binding, but surprisingly does not influence IR-A signalling activation. These findings provide insights into a unique IGF-II residue that can influence receptor binding specificity whilst having little influence on signalling outcome.
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10
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Jiráček J, Žáková L, Marek A. Radiolabeled hormones in insulin research, a minireview. J Labelled Comp Radiopharm 2020; 63:576-581. [PMID: 32909277 DOI: 10.1002/jlcr.3881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/23/2020] [Accepted: 08/30/2020] [Indexed: 11/05/2022]
Abstract
Preparation of both 125 I-labeled insulin and insulin-like growth factor 1 (IGF-1) was critical because it enabled a detailed characterization of binding properties of these important hormones towards their cognate transmembrane receptors. Binding modes of hundreds of hormone derivatives were analyzed using competition radioligand binding assays. This effort has resulted in development of six insulin analogs that are today clinically used for the treatment of diabetes. Here, we will briefly summarize a history of insulin research employing iodinated hormones.
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Affiliation(s)
- Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
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11
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Potalitsyn P, Selicharová I, Sršeň K, Radosavljević J, Marek A, Nováková K, Jiráček J, Žáková L. A radioligand binding assay for the insulin-like growth factor 2 receptor. PLoS One 2020; 15:e0238393. [PMID: 32877466 PMCID: PMC7467306 DOI: 10.1371/journal.pone.0238393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/14/2020] [Indexed: 01/04/2023] Open
Abstract
Insulin-like growth factors 2 and 1 (IGF2 and IGF1) and insulin are closely related hormones that are responsible for the regulation of metabolic homeostasis, development and growth of the organism. Physiological functions of insulin and IGF1 are relatively well-studied, but information about the role of IGF2 in the body is still sparse. Recent discoveries called attention to emerging functions of IGF2 in the brain, where it could be involved in processes of learning and memory consolidation. It was also proposed that these functions could be mediated by the receptor for IGF2 (IGF2R). Nevertheless, little is known about the mechanism of signal transduction through this receptor. Here we produced His-tagged domain 11 (D11), an IGF2-binding element of IGF2R; we immobilized it on the solid support through a well-defined sandwich, consisting of neutravidin, biotin and synthetic anti-His-tag antibodies. Next, we prepared specifically radiolabeled [125I]-monoiodotyrosyl-Tyr2-IGF2 and optimized a sensitive and robust competitive radioligand binding assay for determination of the nanomolar binding affinities of hormones for D11 of IGF2. The assay will be helpful for the characterization of new IGF2 mutants to study the functions of IGF2R and the development of new compounds for the treatment of neurological disorders.
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Affiliation(s)
- Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Kryštof Sršeň
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Jelena Radosavljević
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Kateřina Nováková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
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12
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Xu Y, Kirk NS, Venugopal H, Margetts MB, Croll TI, Sandow JJ, Webb AI, Delaine CA, Forbes BE, Lawrence MC. How IGF-II Binds to the Human Type 1 Insulin-like Growth Factor Receptor. Structure 2020; 28:786-798.e6. [PMID: 32459985 PMCID: PMC7343240 DOI: 10.1016/j.str.2020.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/23/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
Human type 1 insulin-like growth factor receptor (IGF-1R) signals chiefly in response to the binding of insulin-like growth factor I. Relatively little is known about the role of insulin-like growth factor II signaling via IGF-1R, despite the affinity of insulin-like growth factor II for IGF-1R being within an order of magnitude of that of insulin-like growth factor I. Here, we describe the cryoelectron microscopy structure of insulin-like growth factor II bound to a leucine-zipper-stabilized IGF-1R ectodomain, determined in two conformations to a maximum average resolution of 3.2 Å. The two conformations differ in the relative separation of their respective points of membrane entry, and comparison with the structure of insulin-like growth factor I bound to IGF-1R reveals long-suspected differences in the way in which the critical C domain of the respective growth factors interact with IGF-1R.
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Affiliation(s)
- Yibin Xu
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3050, Australia
| | - Nicholas S Kirk
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3050, Australia
| | - Hariprasad Venugopal
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC 3800, Australia
| | - Mai B Margetts
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
| | - Tristan I Croll
- Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge CB2 0XY, UK
| | - Jarrod J Sandow
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3050, Australia
| | - Andrew I Webb
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3050, Australia
| | - Carlie A Delaine
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University of South Australia, Bedford Park, SA 5042, Australia
| | - Briony E Forbes
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University of South Australia, Bedford Park, SA 5042, Australia
| | - Michael C Lawrence
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3050, Australia.
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13
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Pompach P, Viola CM, Radosavljević J, Lin J, Jiráček J, Brzozowski AM, Selicharová I. Cross-Linking/Mass Spectrometry Uncovers Details of Insulin-Like Growth Factor Interaction With Insect Insulin Binding Protein Imp-L2. Front Endocrinol (Lausanne) 2019; 10:695. [PMID: 31649623 PMCID: PMC6794382 DOI: 10.3389/fendo.2019.00695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/25/2019] [Indexed: 11/13/2022] Open
Abstract
Structural details of changes accompanying interaction between insulin-related hormones and their binding partners are often enigmatic. Here, cross-linking/mass spectrometry could complement structural techniques and reveal details of these protein-protein interfaces. We used such approach to clarify missing structural description of the interface in human insulin-like growth factor (IGF-1): Drosophila melanogaster imaginal morphogenesis protein-late 2 protein (Imp-L2) complex which we studied previously by X-ray crystallography. We crosslinked these proteins by heterobifunctional cross-linker sulfosuccinimidyl 4,4'-azidopentanoate (Sulfo-SDA) for the subsequent mass spectrometry (MS) analysis. The MS analysis revealed IGF-1:Imp-L2 interactions which were not resolved in the crystal structure of this assembly, and they converged with X-ray results, indicating the importance of the IGF-1 N-terminus interaction with the C-terminal (185-242) part of the Imp-L2 for stability of this complex. Here, we also showed the advantage and reliability of MS approach in solving details of protein-protein interactions that are too flexible for solid state structural methods.
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Affiliation(s)
- Petr Pompach
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czechia
| | - Cristina M. Viola
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York, United Kingdom
| | - Jelena Radosavljević
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - Jingjing Lin
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York, United Kingdom
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
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14
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Macháčková K, Mlčochová K, Potalitsyn P, Hanková K, Socha O, Buděšínský M, Muždalo A, Lepšík M, Černeková M, Radosavljević J, Fábry M, Mitrová K, Chrudinová M, Lin J, Yurenko Y, Hobza P, Selicharová I, Žáková L, Jiráček J. Mutations at hypothetical binding site 2 in insulin and insulin-like growth factors 1 and 2 result in receptor- and hormone-specific responses. J Biol Chem 2019; 294:17371-17382. [PMID: 31558604 PMCID: PMC6873181 DOI: 10.1074/jbc.ra119.010072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/23/2019] [Indexed: 11/26/2022] Open
Abstract
Information on how insulin and insulin-like growth factors 1 and 2 (IGF-1 and -2) activate insulin receptors (IR-A and -B) and the IGF-1 receptor (IGF-1R) is crucial for understanding the difference in the biological activities of these peptide hormones. Cryo-EM studies have revealed that insulin uses its binding sites 1 and 2 to interact with IR-A and have identified several critical residues in binding site 2. However, mutagenesis studies suggest that Ile-A10, Ser-A12, Leu-A13, and Glu-A17 also belong to insulin's site 2. Here, to resolve this discrepancy, we mutated these insulin residues and the equivalent residues in IGFs. Our findings revealed that equivalent mutations in the hormones can result in differential biological effects and that these effects can be receptor-specific. We noted that the insulin positions A10 and A17 are important for its binding to IR-A and IR-B and IGF-1R and that A13 is important only for IR-A and IR-B binding. The IGF-1/IGF-2 positions 51/50 and 54/53 did not appear to play critical roles in receptor binding, but mutations at IGF-1 position 58 and IGF-2 position 57 affected the binding. We propose that IGF-1 Glu-58 interacts with IGF-1R Arg-704 and belongs to IGF-1 site 1, a finding supported by the NMR structure of the less active Asp-58–IGF-1 variant. Computational analyses indicated that the aforementioned mutations can affect internal insulin dynamics and inhibit adoption of a receptor-bound conformation, important for binding to receptor site 1. We provide a molecular model and alternative hypotheses for how the mutated insulin residues affect activity.
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Affiliation(s)
- Kateřina Macháčková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Květoslava Mlčochová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Kateřina Hanková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Ondřej Socha
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Miloš Buděšínský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Anja Muždalo
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Michaela Černeková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Jelena Radosavljević
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Milan Fábry
- Institute of Molecular Genetics, Czech Academy of Sciences, 166 37 Prague 6, Czech Republic
| | - Katarína Mitrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Jingjing Lin
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Yevgen Yurenko
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Pavel Hobza
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
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15
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Fabre B, Pícha J, Selicharová I, Žáková L, Chrudinová M, Hajduch J, Jiráček J. Probing Tripodal Peptide Scaffolds as Insulin and IGF-1 Receptor Ligands. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Benjamin Fabre
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jan Pícha
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jan Hajduch
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
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16
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Macháčková K, Chrudinová M, Radosavljević J, Potalitsyn P, Křížková K, Fábry M, Selicharová I, Collinsová M, Brzozowski AM, Žáková L, Jiráček J. Converting Insulin-like Growth Factors 1 and 2 into High-Affinity Ligands for Insulin Receptor Isoform A by the Introduction of an Evolutionarily Divergent Mutation. Biochemistry 2018; 57:2373-2382. [DOI: 10.1021/acs.biochem.7b01260] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kateřina Macháčková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Jelena Radosavljević
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Květoslava Křížková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Milan Fábry
- Institute of Molecular Genetics, The Czech Academy of Sciences, Flemingovo n. 2, 166 37 Prague 6, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Michaela Collinsová
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York YO10 5DD, United Kingdom
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám 2, 166 10 Prague 6, Czech Republic
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17
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Macháčková K, Collinsová M, Chrudinová M, Selicharová I, Pícha J, Buděšínský M, Vaněk V, Žáková L, Brzozowski AM, Jiráček J. Insulin-like Growth Factor 1 Analogs Clicked in the C Domain: Chemical Synthesis and Biological Activities. J Med Chem 2017; 60:10105-10117. [DOI: 10.1021/acs.jmedchem.7b01331] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kateřina Macháčková
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Michaela Collinsová
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Martina Chrudinová
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Irena Selicharová
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Jan Pícha
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Miloš Buděšínský
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Václav Vaněk
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Lenka Žáková
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Andrzej M. Brzozowski
- York
Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York YO10 5DD, United Kingdom
| | - Jiří Jiráček
- Institute
of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
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18
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Jiráček J, Žáková L. Structural Perspectives of Insulin Receptor Isoform-Selective Insulin Analogs. Front Endocrinol (Lausanne) 2017; 8:167. [PMID: 28798723 PMCID: PMC5529358 DOI: 10.3389/fendo.2017.00167] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 06/29/2017] [Indexed: 01/16/2023] Open
Abstract
A significant drawback of the exogenous administration of insulin to diabetics is the non-physiological profile of insulin action resulting in the insufficient suppression of hepatic glucose production, which is the main contributing factor to diabetic hyperglycemia under fasting conditions and the basis of the challenge to restore a more physiological glucose profile in diabetes. The insulin receptor (IR) exists in two alternatively spliced variants, IR-A and IR-B, with different tissue distribution. While peripheral tissues contain different proportions of both isoforms, hepatic cells almost exclusively contain IR-B. In this respect, IR-B-selective insulin analogs would be of great interest for their potential to restore more natural metabolic homeostasis in diabetes. Recent advances in the structural biology of insulin and IR have provided new clues for understanding the interaction of both proteins. This article discusses and offers some structural perspectives for the design of specific insulin analogs with a preferential binding to IR-B.
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Affiliation(s)
- Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
- *Correspondence: Jiří Jiráček,
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
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