1
|
Sen S, Ali R, Onkar A, Verma S, Ahmad QT, Bhadauriya P, Sinha P, Nair NN, Ganesh S, Verma S. Synthesis of a highly thermostable insulin by phenylalanine conjugation at B29 Lysine. Commun Chem 2024; 7:161. [PMID: 39043846 PMCID: PMC11266353 DOI: 10.1038/s42004-024-01241-z] [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] [Received: 02/25/2024] [Accepted: 07/10/2024] [Indexed: 07/25/2024] Open
Abstract
Globally, millions of diabetic patients require daily life-saving insulin injections. Insulin heat-lability and fibrillation pose significant challenges, especially in parts of the world without ready access to uninterrupted refrigeration. Here, we have synthesized four human insulin analogs by conjugating ε-amine of B29 lysine of insulin with acetic acid, phenylacetic acid, alanine, and phenylalanine residues. Of these, phenylalanine-conjugated insulin, termed FHI, was the most stable under high temperature (65 °C), elevated salt stress (25 mM NaCl), and varying pH levels (ranging from highly acidic pH 1.6 to physiological pH 7.4). It resists fibrillation for a significantly longer duration with sustained biological activity in in vitro, ex vivo, and in vivo and displays prolonged stability over its native counterpart. We further unravel the critical interactions, such as additional aromatic π-π interactions and hydrogen bonding in FHI, that are notably absent in native insulin. These interactions confer enhanced structural stability of FHI and offer a promising solution to the challenges associated with insulin heat sensitivity.
Collapse
Affiliation(s)
- Shantanu Sen
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Rafat Ali
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Akanksha Onkar
- Department of Biological Sciences & Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, 94143, CA, USA
| | - Shivani Verma
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Quazi Taushif Ahmad
- Department of Biological Sciences & Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Pratibha Bhadauriya
- Department of Biological Sciences & Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Pradip Sinha
- Department of Biological Sciences & Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - Subramaniam Ganesh
- Department of Biological Sciences & Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
- Mehta Family Centre for Engineering in Medicine, Indian Institute of Technology, Kanpur, 208016, UP, India
- Gangwal School of Medical Sciences and Technology, Indian Institute of Technology, Kanpur, 208016, UP, India
| | - Sandeep Verma
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India.
- Mehta Family Centre for Engineering in Medicine, Indian Institute of Technology, Kanpur, 208016, UP, India.
- Gangwal School of Medical Sciences and Technology, Indian Institute of Technology, Kanpur, 208016, UP, India.
| |
Collapse
|
2
|
Varas N, Grabowski R, Jarosinski MA, Tai N, Herzog RI, Ismail-Beigi F, Yang Y, Cherrington AD, Weiss MA. Ultra-stable insulin-glucagon fusion protein exploits an endogenous hepatic switch to mitigate hypoglycemic risk. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.594997. [PMID: 38826486 PMCID: PMC11142066 DOI: 10.1101/2024.05.20.594997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
The risk of hypoglycemia and its serious medical sequelae restrict insulin replacement therapy for diabetes mellitus. Such adverse clinical impact has motivated development of diverse glucose-responsive technologies, including algorithm-controlled insulin pumps linked to continuous glucose monitors ("closed-loop systems") and glucose-sensing ("smart") insulins. These technologies seek to optimize glycemic control while minimizing hypoglycemic risk. Here, we describe an alternative approach that exploits an endogenous glucose-dependent switch in hepatic physiology: preferential insulin signaling (under hyperglycemic conditions) versus preferential counter-regulatory glucagon signaling (during hypoglycemia). Motivated by prior reports of glucagon-insulin co-infusion, we designed and tested an ultra-stable glucagon-insulin fusion protein whose relative hormonal activities were calibrated by respective modifications; physical stability was concurrently augmented to facilitate formulation, enhance shelf life and expand access. An N-terminal glucagon moiety was stabilized by an α-helix-compatible Lys 13 -Glu 17 lactam bridge; A C-terminal insulin moiety was stabilized as a single chain with foreshortened C domain. Studies in vitro demonstrated (a) resistance to fibrillation on prolonged agitation at 37 °C and (b) dual hormonal signaling activities with appropriate balance. Glucodynamic responses were monitored in rats relative to control fusion proteins lacking one or the other hormonal activity, and continuous intravenous infusion emulated basal subcutaneous therapy. Whereas efficacy in mitigating hyperglycemia was unaffected by the glucagon moiety, the fusion protein enhanced endogenous glucose production under hypoglycemic conditions. Together, these findings provide proof of principle toward a basal glucose-responsive insulin biotechnology of striking simplicity. The fusion protein's augmented stability promises to circumvent the costly cold chain presently constraining global insulin access. Significance Statement The therapeutic goal of insulin replacement therapy in diabetes is normalization of blood-glucose concentration, which prevents or delays long-term complications. A critical barrier is posed by recurrent hypoglycemic events that results in short- and long-term morbidities. An innovative approach envisions co-injection of glucagon (a counter-regulatory hormone) to exploit a glycemia-dependent hepatic switch in relative hormone responsiveness. To provide an enabling technology, we describe an ultra-stable fusion protein containing insulin- and glucagon moieties. Proof of principle was obtained in rats. A single-chain insulin moiety provides glycemic control whereas a lactam-stabilized glucagon extension mitigates hypoglycemia. This dual-hormone fusion protein promises to provide a basal formulation with reduced risk of hypoglycemia. Resistance to fibrillation may circumvent the cold chain required for global access.
Collapse
|
3
|
Xu R, Jap E, Gubbins B, Hagemeyer CE, Karas JA. Semisynthesis of A6-A11 lactam insulin. J Pept Sci 2024; 30:e3542. [PMID: 37697741 PMCID: PMC10909544 DOI: 10.1002/psc.3542] [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: 06/05/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/13/2023]
Abstract
Insulin replacement therapy is essential for the management of diabetes. However, despite the relative success of this therapeutic strategy, there is still a need to improve glycaemic control and the overall quality of life of patients. This need has driven research into orally available, glucose-responsive and rapid-acting insulins. A key consideration during analogue development is formulation stability, which can be improved via the replacement of insulin's A6-A11 disulfide bond with stable mimetics. Unfortunately, analogues such as these require extensive chemical synthesis to incorporate the nonnative cross-links, which is not a scalable synthetic approach. To address this issue, we demonstrate proof of principle for the semisynthesis of insulin analogues bearing nonnative A6-A11 cystine isosteres. The key feature of our synthetic strategy involves the use of several biosynthetically derived peptide precursors which can be produced at scale cost-effectively and a small, chemically synthesised A6-A11 macrocyclic lactam fragment. Although the assembled A6-A11 lactam insulin possesses poor biological activity in vitro, our synthetic strategy can be applied to other disulfide mimetics that have been shown to improve thermal stability without significantly affecting activity and structure. Moreover, we envisage that this new semisynthetic approach will underpin a new generation of hyperstable proteomimetics.
Collapse
Affiliation(s)
- Rong Xu
- Australian Centre for Blood DiseasesMonash UniversityMelbourneVictoria3004Australia
| | - Edwina Jap
- Australian Centre for Blood DiseasesMonash UniversityMelbourneVictoria3004Australia
| | - Ben Gubbins
- School of ChemistryThe University of MelbourneMelbourneVictoria3010Australia
| | | | - John A. Karas
- School of ChemistryThe University of MelbourneMelbourneVictoria3010Australia
| |
Collapse
|
4
|
Andrasi M, Vishwakarma G, Szabo R, Nagy C, Gaspar A. Comparative study on the deamidation of three recombinant human insulins using capillary electrophoresis. J Chromatogr A 2023; 1706:464286. [PMID: 37573758 DOI: 10.1016/j.chroma.2023.464286] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/03/2023] [Accepted: 08/06/2023] [Indexed: 08/15/2023]
Abstract
The applicability of capillary zone electrophoresis (CZE) for the separation of different recombinant human insulins and their deamidated isoforms was studied. The high resolving power of CZE is demonstrated by its ability to separate insulin isoforms differing only by 0.984 Da (different-fold deamidated forms) and even components having the exacts same mass but slightly different shapes (same-fold deamidated forms). From among the several insulins available, humulin, glargine and glulisine were selected for our study because their sequences and chemical parameters are quite similar, however, the small differences present in their amino acid sequences influence the deamidation processes. Using a background electrolyte with basic pH was favourable not only for the separation of the different types of insulin but also for the separation of deamidated protein forms even in a bare fused silica capillary. The LOD values ranged between 0.6 - 0.93 mg/L and 2.17 - 4.37 mg/L for UV and ESI-MS detection, respectively. At -20 - -80 °C, the deamidation is minimal, but at temperatures above +5 °C deamidation is accelerated. At +5 °C only 1-fold deamidation forms could be observed for each insulin. Acidified samples incubated for 1-month at room temperature showed varying levels of deamidation: 1-fold, 1-2-fold and 1-2-3-fold forms for glargine, glulisine and humulin, respectively.
Collapse
Affiliation(s)
- M Andrasi
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1., Debrecen H-4032, Hungary
| | - G Vishwakarma
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1., Debrecen H-4032, Hungary
| | - R Szabo
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1., Debrecen H-4032, Hungary
| | - C Nagy
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1., Debrecen H-4032, Hungary
| | - A Gaspar
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1., Debrecen H-4032, Hungary.
| |
Collapse
|
5
|
Zeng Z, Hou W, Hu Z, Liu L, Liu Z, Shi Y, Li M, Chen Y. Long-Acting Insulin-Zwitterionic Polymer Conjugate Mitigates Hypoglycemia. Chemistry 2023; 29:e202203460. [PMID: 36445789 DOI: 10.1002/chem.202203460] [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: 11/08/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 11/30/2022]
Abstract
Insulin, a main medication to control glycemia of type 1 and advanced type 2 diabetes, faces problems of a short half-life and poor stability during its clinical use. Zwitterionic polymer shows unique properties of antifouling and low immunogenicity. Here, we have synthesized a new insulin-zwitterionic polymer conjugate (INS-PMPC) through grafting-from strategy by controlled radical polymerization. Apart from showing excellent stability upon mechanical agitation, the resulting INS-PMPC conjugate provided over 20 h of glycemic control due to improved pharmacokinetics in diabetic mice with one single subcutaneous injection. Most importantly, this insulin-zwitterionic polymer conjugate significantly decreases the incidence of hypoglycemia.
Collapse
Affiliation(s)
- Zhipeng Zeng
- Laboratory of Biomaterials and Translational Medicine Center for Nanomedicine The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510630, P. R. China
| | - Wangmeng Hou
- School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Zhitao Hu
- School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Lixin Liu
- School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Zhijia Liu
- School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Yi Shi
- School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Mingqiang Li
- Laboratory of Biomaterials and Translational Medicine Center for Nanomedicine The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510630, P. R. China
| | - Yongming Chen
- Laboratory of Biomaterials and Translational Medicine Center for Nanomedicine The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510630, P. R. China.,School of Materials Science and Engineering Center of Functional Biomaterials Key Laboratory of Polymeric Composite Materials and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| |
Collapse
|
6
|
Smith NA, Menting JG, Weiss MA, Lawrence MC, Smith BJ. Single-chain insulin analogs threaded by the insulin receptor αCT domain. Biophys J 2022; 121:4063-4077. [PMID: 36181268 PMCID: PMC9675026 DOI: 10.1016/j.bpj.2022.09.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/12/2022] [Accepted: 09/28/2022] [Indexed: 11/18/2022] Open
Abstract
Insulin is a mainstay of therapy for diabetes mellitus, yet its thermal stability complicates global transportation and storage. Cold-chain transport, coupled with optimized formulation and materials, prevents to some degree nucleation of amyloid and hence inactivation of hormonal activity. These issues hence motivate the design of analogs with increased stability, with a promising approach being single-chain insulins (SCIs), whose C domains (foreshortened relative to proinsulin) resemble those of the single-chain growth factors (IGFs). We have previously demonstrated that optimized SCIs can exhibit native-like hormonal activity with enhanced thermal stability and marked resistance to fibrillation. Here, we describe the crystal structure of an ultrastable SCI (C-domain length 6; sequence EEGPRR) bound to modules of the insulin receptor (IR) ectodomain (N-terminal α-subunit domains L1-CR and C-terminal αCT peptide; "microreceptor" [μIR]). The structure of the SCI-μIR complex, stabilized by an Fv module, was determined using diffraction data to a resolution of 2.6 Å. Remarkably, the αCT peptide (IR-A isoform) "threads" through a gap between the flexible C domain and the insulin core. To explore such threading, we undertook molecular dynamics simulations to 1) compare threaded with unthreaded binding modes and 2) evaluate effects of C-domain length on these alternate modes. The simulations (employing both conventional and enhanced sampling simulations) provide evidence that very short linkers (C-domain length of -1) would limit gap opening in the SCI and so impair threading. We envisage that analogous threading occurs in the intact SCI-IR complex-rationalizing why minimal C-domain lengths block complete activity-and might be exploited to design novel receptor-isoform-specific analogs.
Collapse
Affiliation(s)
- Nicholas A Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - John G Menting
- WEHI, Parkville, Victoria, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana.
| | - Michael C Lawrence
- WEHI, Parkville, Victoria, Australia; Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria, Australia.
| | - Brian J Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.
| |
Collapse
|
7
|
Sen S, Ali R, Onkar A, Ganesh S, Verma S. Strategies for interference of insulin fibrillogenesis: challenges and advances. Chembiochem 2022; 23:e202100678. [PMID: 35025120 DOI: 10.1002/cbic.202100678] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/11/2022] [Indexed: 11/10/2022]
Abstract
The discovery of insulin came up with very high hopes for diabetic patients. In the year 2021, the world celebrated the 100 th anniversary of the discovery of this vital hormone. However, external use of insulin is highly affected by its aggregating tendency that occurs during its manufacturing, transportation, and improper handling which ultimately leads its pharmaceutically and biologically ineffective form. In this review, we aim to discuss the various approaches used for decelerating insulin aggregation which results in the enhancement of its overall structural stability and usage. The approaches that are discussed are broadly classified as either a measure through excipient additions or by intrinsic modifications in the insulin native structure.
Collapse
Affiliation(s)
- Shantanu Sen
- Indian Institute of Technology Kanpur, Chemistry, INDIA
| | - Rafat Ali
- Indian Institute of Technology Kanpur, Chemistry, Room No 131 Lab No2, CESE department IIT Kanpur, 208016, Kanpur, INDIA
| | - Akanksha Onkar
- Indian Institute of Technology Kanpur, Biological Sciences and Bioengineering, INDIA
| | - Subramaniam Ganesh
- Indian Institute of Technology Kanpur, Biological Sciences and Bioengineering, INDIA
| | - Sandeep Verma
- Indian Institute of Technology-Kanpur, Department of Chemistry, IIT-Kanpur, 208016, Kanpur, INDIA
| |
Collapse
|
8
|
Chen YS, Gleaton J, Yang Y, Dhayalan B, Phillips NB, Liu Y, Broadwater L, Jarosinski MA, Chatterjee D, Lawrence MC, Hattier T, Michael MD, Weiss MA. Insertion of a synthetic switch into insulin provides metabolite-dependent regulation of hormone-receptor activation. Proc Natl Acad Sci U S A 2021; 118:e2103518118. [PMID: 34290145 PMCID: PMC8325334 DOI: 10.1073/pnas.2103518118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Insulin-signaling requires conformational change: whereas the free hormone and its receptor each adopt autoinhibited conformations, their binding leads to structural reorganization. To test the functional coupling between insulin's "hinge opening" and receptor activation, we inserted an artificial ligand-dependent switch into the insulin molecule. Ligand-binding disrupts an internal tether designed to stabilize the hormone's native closed and inactive conformation, thereby enabling productive receptor engagement. This scheme exploited a diol sensor (meta-fluoro-phenylboronic acid at GlyA1) and internal diol (3,4-dihydroxybenzoate at LysB28). The sensor recognizes monosaccharides (fructose > glucose). Studies of insulin-signaling in human hepatoma-derived cells (HepG2) demonstrated fructose-dependent receptor autophosphorylation leading to appropriate downstream signaling events, including a specific kinase cascade and metabolic gene regulation (gluconeogenesis and lipogenesis). Addition of glucose (an isomeric ligand with negligible sensor affinity) did not activate the hormone. Similarly, metabolite-regulated signaling was not observed in control studies of 1) an unmodified insulin analog or 2) an analog containing a diol sensor without internal tethering. Although secondary structure (as probed by circular dichroism) was unaffected by ligand-binding, heteronuclear NMR studies revealed subtle local and nonlocal monosaccharide-dependent changes in structure. Insertion of a synthetic switch into insulin has thus demonstrated coupling between hinge-opening and allosteric holoreceptor signaling. In addition to this foundational finding, our results provide proof of principle for design of a mechanism-based metabolite-responsive insulin. In particular, replacement of the present fructose sensor by an analogous glucose sensor may enable translational development of a "smart" insulin analog to mitigate hypoglycemic risk in diabetes therapy.
Collapse
Affiliation(s)
- Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | | | - Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Yule Liu
- Thermalin Inc., Cleveland, OH 44106
| | | | - Mark A Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael C Lawrence
- Structural Biology Division, WEHI, Parkville, VIC 3052, Australia
- Department of Medical Biology, University of Melbourne, Royal Parade, Parkville, VIC 3050, Australia
| | | | | | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202;
| |
Collapse
|
9
|
Dec R, Dzwolak W. A tale of two tails: Self-assembling properties of A- and B-chain parts of insulin's highly amyloidogenic H-fragment. Int J Biol Macromol 2021; 186:510-518. [PMID: 34271044 DOI: 10.1016/j.ijbiomac.2021.07.057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/26/2021] [Accepted: 07/08/2021] [Indexed: 11/27/2022]
Abstract
Due to the spontaneous transition of native insulin into therapeutically inactive amyloid, prolonged storage decreases effectiveness of the hormone in treatment of diabetes. Various regions of the amino acid sequence have been implicated in insulin aggregation. Here, we focus on smaller fragments of the highly amyloidogenic H-peptide comprising disulfide-bonded N-terminal sections of insulin's A-chain (13 residues) and B-chain (11 residues). Aggregation patterns of N-terminal fragments of A-chain (ACC1-13, ACC1-11, ACC6-13, ACC6-11, all retaining Cys6A-Cys11A disulfide bond) and B-chain (B1-11(7A)) are examined at acidic and neutral pH. ACC1-11 is the smallest fragment found to be amyloidogenic at either pH; removal of the N-terminal GIVEQ section renders this fragment entirely non-amyloidogenic. The self-assembling properties of ACC1-11 contrast with aggregation-resistant behavior of B1-11(7A) and its disulfide-linked homodimer, (B1-11)2 aggregating only at neutral pH. Fibrillar ACC1-11 is similar to insulin amyloid in terms of morphology and infrared features. Secondary nucleation is likely to account for the detected shortening of insulin aggregation lag phase at neutral pH upon cross-seeding with pre-formed fibrils of ACC1-11 or (B1-11)2. An aggregation-enhancing effect of monomeric ACC1-11 on co-dissolved native insulin is also observed. Our findings are discussed in the context of mechanisms of insulin aggregation.
Collapse
Affiliation(s)
- Robert Dec
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., 02-093 Warsaw, Poland
| | - Wojciech Dzwolak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., 02-093 Warsaw, Poland.
| |
Collapse
|
10
|
Jarosinski MA, Dhayalan B, Rege N, Chatterjee D, Weiss MA. 'Smart' insulin-delivery technologies and intrinsic glucose-responsive insulin analogues. Diabetologia 2021; 64:1016-1029. [PMID: 33710398 PMCID: PMC8158166 DOI: 10.1007/s00125-021-05422-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/15/2021] [Indexed: 02/08/2023]
Abstract
Insulin replacement therapy for diabetes mellitus seeks to minimise excursions in blood glucose concentration above or below the therapeutic range (hyper- or hypoglycaemia). To mitigate acute and chronic risks of such excursions, glucose-responsive insulin-delivery technologies have long been sought for clinical application in type 1 and long-standing type 2 diabetes mellitus. Such 'smart' systems or insulin analogues seek to provide hormonal activity proportional to blood glucose levels without external monitoring. This review highlights three broad strategies to co-optimise mean glycaemic control and time in range: (1) coupling of continuous glucose monitoring (CGM) to delivery devices (algorithm-based 'closed-loop' systems); (2) glucose-responsive polymer encapsulation of insulin; and (3) mechanism-based hormone modifications. Innovations span control algorithms for CGM-based insulin-delivery systems, glucose-responsive polymer matrices, bio-inspired design based on insulin's conformational switch mechanism upon insulin receptor engagement, and glucose-responsive modifications of new insulin analogues. In each case, innovations in insulin chemistry and formulation may enhance clinical outcomes. Prospects are discussed for intrinsic glucose-responsive insulin analogues containing a reversible switch (regulating bioavailability or conformation) that can be activated by glucose at high concentrations.
Collapse
Affiliation(s)
- Mark A Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nischay Rege
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Chemistry, Indiana University, Bloomington, IN, USA.
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
11
|
Abstract
The pancreatic peptide hormone insulin, first discovered exactly 100 years ago, is essential for glycemic control and is used as a therapeutic for the treatment of type 1 and, increasingly, type 2 diabetes. With a worsening global diabetes epidemic and its significant health budget imposition, there is a great demand for new analogues possessing improved physical and functional properties. However, the chemical synthesis of insulin's intricate 51-amino acid, two-chain, three-disulfide bond structure, together with the poor physicochemical properties of both the individual chains and the hormone itself, has long represented a major challenge to organic chemists. This review provides a timely overview of the past efforts to chemically assemble this fascinating hormone using an array of strategies to enable both correct folding of the two chains and selective formation of disulfide bonds. These methods not only have contributed to general peptide synthesis chemistry and enabled access to the greatly growing numbers of insulin-like and cystine-rich peptides but also, today, enable the production of insulin at the synthetic efficiency levels of recombinant DNA expression methods. They have led to the production of a myriad of novel analogues with optimized structural and functional features and of the feasibility for their industrial manufacture.
Collapse
|
12
|
Sadrjavadi K, Barzegari E, Khaledian S, Derakhshankhah H, Fattahi A. Interactions of insulin with tragacanthic acid biopolymer: Experimental and computational study. Int J Biol Macromol 2020; 164:321-330. [PMID: 32682034 DOI: 10.1016/j.ijbiomac.2020.07.122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/11/2020] [Accepted: 07/12/2020] [Indexed: 02/07/2023]
Abstract
Alternative methods for insulin delivery instead of subcutaneous injection in diabetic patients is of great essential, and biocompatible polymers are one of the most efficient vehicles for this purpose. This research aims to investigate the capability of tragacanthic acid (TA) to bind insulin and release it under physiological conditions without alteration in the structure and conformation of insulin. Interactions between TA and insulin were studied using spectroscopic techniques and computational modeling by docking and molecular dynamics simulations. Our results demonstrate an entropy-driven spontaneous interaction between insulin and TA, where hydrogen bonds act as the main enthalpic contribution. According to our findings, the weak interaction between insulin and TA provides the basis for efficient capture and appropriate release of insulin by TA as a potential part of the insulin delivery system. In conclusion, tragacanth acid can be a proper candidate for insulin delivery.
Collapse
Affiliation(s)
- Komail Sadrjavadi
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415153, Iran; Department of Biology, Faculty of Science, Razi University, Kermanshah 6714115111, Iran
| | - Ebrahim Barzegari
- Medical Biology Research Center, Health Technologies Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415185, Iran
| | - Salar Khaledian
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415153, Iran
| | - Hossein Derakhshankhah
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415153, Iran
| | - Ali Fattahi
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415153, Iran; Medical Biology Research Center, Health Technologies Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415185, Iran.
| |
Collapse
|
13
|
Østergaard M, Mishra NK, Jensen KJ. The ABC of Insulin: The Organic Chemistry of a Small Protein. Chemistry 2020; 26:8341-8357. [DOI: 10.1002/chem.202000337] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/15/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Mads Østergaard
- Department of ChemistryUniversity of Copenhagen Thorvaldsensvej 40 1871 Frederiksberg C Denmark
| | - Narendra Kumar Mishra
- Department of ChemistryUniversity of Copenhagen Thorvaldsensvej 40 1871 Frederiksberg C Denmark
| | - Knud J. Jensen
- Department of ChemistryUniversity of Copenhagen Thorvaldsensvej 40 1871 Frederiksberg C Denmark
| |
Collapse
|
14
|
Zheng N, Karra P, VandenBerg MA, Kim JH, Webber MJ, Holland WL, Chou DHC. Synthesis and Characterization of an A6-A11 Methylene Thioacetal Human Insulin Analogue with Enhanced Stability. J Med Chem 2019; 62:11437-11443. [PMID: 31804076 PMCID: PMC7217704 DOI: 10.1021/acs.jmedchem.9b01589] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Insulin has been a life-saving drug for millions of people with diabetes. However, several challenges exist which limit therapeutic benefits and reduce patient convenience. One key challenge is the fibrillation propensity, which necessitates refrigeration for storage. To address this limitation, we chemically synthesized and evaluated a methylene thioacetal human insulin analogue (SCS-Ins). The synthesized SCS-Ins showed enhanced serum stability and aggregation resistance while retaining bioactivity compared with native insulin.
Collapse
Affiliation(s)
- Nan Zheng
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, United States
| | - Prasoona Karra
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT 84112, United States
| | - Michael A. VandenBerg
- Department of Chemical Engineering, University of Notre Dame, Notre Dame, IN 46556, United States
| | - Jin Hwan Kim
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, United States
| | - Matthew J. Webber
- Department of Chemical Engineering, University of Notre Dame, Notre Dame, IN 46556, United States
| | - William L. Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT 84112, United States
| | - Danny Hung-Chieh Chou
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, United States
| |
Collapse
|
15
|
Hossain MA, Okamoto R, Karas JA, Praveen P, Liu M, Forbes BE, Wade JD, Kajihara Y. Total Chemical Synthesis of a Nonfibrillating Human Glycoinsulin. J Am Chem Soc 2019; 142:1164-1169. [DOI: 10.1021/jacs.9b11424] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
| | - Ryo Okamoto
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 Japan
| | | | | | | | - Briony E. Forbes
- Discipline of Medical Biochemistry, College of Medicine and Public Health, Flinders University, Bedford Park, South Australia 5042, Australia
| | | | - Yasuhiro Kajihara
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 Japan
| |
Collapse
|
16
|
Xiong X, Blakely A, Karra P, VandenBerg MA, Ghabash G, Whitby F, Zhang YW, Webber MJ, Holland WL, Hill CP, Chou DHC. Novel four-disulfide insulin analog with high aggregation stability and potency. Chem Sci 2019; 11:195-200. [PMID: 32110371 PMCID: PMC7012051 DOI: 10.1039/c9sc04555d] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/05/2019] [Indexed: 12/15/2022] Open
Abstract
A novel four-disulfide insulin analog was designed with retained bioactivity and increased fibrillation stability.
Although insulin was first purified and used therapeutically almost a century ago, there is still a need to improve therapeutic efficacy and patient convenience. A key challenge is the requirement for refrigeration to avoid inactivation of insulin by aggregation/fibrillation. Here, in an effort to mitigate this problem, we introduced a 4th disulfide bond between a C-terminal extended insulin A chain and residues near the C-terminus of the B chain. Insulin activity was retained by an analog with an additional disulfide bond between residues A22 and B22, while other linkages tested resulted in much reduced potency. Furthermore, the A22-B22 analog maintains the native insulin tertiary structure as demonstrated by X-ray crystal structure determination. We further demonstrate that this four-disulfide analog has similar in vivo potency in mice compared to native insulin and demonstrates higher aggregation stability. In conclusion, we have discovered a novel four-disulfide insulin analog with high aggregation stability and potency.
Collapse
Affiliation(s)
- Xiaochun Xiong
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | - Alan Blakely
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | - Prasoona Karra
- Department of Nutrition and Integrative Physiology , University of Utah , Salt Lake City UT 84112 , USA
| | - Michael A VandenBerg
- Department of Chemical & Biomolecular Engineering , University of Notre Dame , IN 46556 , USA
| | - Gabrielle Ghabash
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | - Frank Whitby
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | - Yi Wolf Zhang
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | - Matthew J Webber
- Department of Chemical & Biomolecular Engineering , University of Notre Dame , IN 46556 , USA
| | - William L Holland
- Department of Nutrition and Integrative Physiology , University of Utah , Salt Lake City UT 84112 , USA
| | - Christopher P Hill
- Department of Biochemistry , University of Utah , Salt Lake City UT 84112 , USA . ;
| | | |
Collapse
|
17
|
Mao R, Chen Y, Chi Z, Wang Y. Insulin and its single-chain analogue. Appl Microbiol Biotechnol 2019; 103:8737-8751. [PMID: 31637493 DOI: 10.1007/s00253-019-10170-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 10/02/2019] [Accepted: 10/08/2019] [Indexed: 12/26/2022]
|
18
|
Mao R, Chen Y, Wu Q, Zhang T, Diao E, Wu D, Wang M, Liu Y, Lu L, Chang X, Zheng Y, Wang Y. Oral delivery of single-chain insulin (SCI-59) analog by bacterium-like particles (BLPs) induces oral tolerance and prevents autoimmune diabetes in NOD mice. Immunol Lett 2019; 214:37-44. [DOI: 10.1016/j.imlet.2019.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/18/2019] [Accepted: 08/28/2019] [Indexed: 12/11/2022]
|
19
|
Glucose-responsive insulin by molecular and physical design. Nat Chem 2019; 9:937-943. [PMID: 28937662 DOI: 10.1038/nchem.2857] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 07/11/2017] [Indexed: 12/15/2022]
Abstract
The concept of a glucose-responsive insulin (GRI) has been a recent objective of diabetes technology. The idea behind the GRI is to create a therapeutic that modulates its potency, concentration or dosing relative to a patient's dynamic glucose concentration, thereby approximating aspects of a normally functioning pancreas. From the perspective of the medicinal chemist, the GRI is also important as a generalized model of a potentially new generation of therapeutics that adjust potency in response to a critical therapeutic marker. The aim of this Perspective is to highlight emerging concepts, including mathematical modelling and the molecular engineering of insulin itself and its potency, towards a viable GRI. We briefly outline some of the most important recent progress toward this goal and also provide a forward-looking viewpoint, which asks if there are new approaches that could spur innovation in this area as well as to encourage synthetic chemists and chemical engineers to address the challenges and promises offered by this therapeutic approach.
Collapse
|
20
|
Jeong MY, Rutter J, Chou DHC. Display of Single-Chain Insulin-like Peptides on a Yeast Surface. Biochemistry 2019; 58:182-188. [PMID: 30575376 DOI: 10.1021/acs.biochem.8b01094] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin and insulin-like peptides play a pivotal role in a wide variety of cellular and physiological events, including energy storage, proliferation, aging, and differentiation. Variants of insulin and insulin-like peptides may therefore be probes for studying the insulin signaling pathway and therapeutic candidates for treating metabolic diseases. Here, we report a method for genetically displaying single-chain insulin-like peptides on the surface of Saccharomyces cerevisiae strain DY1632. Using a previously reported single-chain insulin analogue, SCI-57, as a model, we demonstrate that nearly 70% of yeast binds to insulin receptor (IR), suggesting that SCI-57 is folded correctly and maintains its IR binding property. Furthermore, the interaction between displayed SCI-57 and IR can be weakened using increasing concentrations of native insulin as a soluble competitor, suggesting that the interaction is insulin-dependent. We further applied this methodology to three other single-chain insulin analogues with various lengths and confirmed their interactions with IR. In summary, we successfully displayed a number of insulin-like peptides on a yeast surface and demonstrated insulin-dependent interactions with IR. This method may, therefore, be used for construction of libraries of insulin-like peptides to select for chemical probes or therapeutic molecules.
Collapse
|
21
|
Wang C, Sudlow G, Wang Z, Cao S, Jiang Q, Neiner A, Morrissey JJ, Kharasch ED, Achilefu S, Singamaneni S. Metal-Organic Framework Encapsulation Preserves the Bioactivity of Protein Therapeutics. Adv Healthc Mater 2018; 7:e1800950. [PMID: 30369102 PMCID: PMC6453541 DOI: 10.1002/adhm.201800950] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Indexed: 12/30/2022]
Abstract
Protein therapeutics are prone to lose their structure and bioactivity under various environmental stressors. This study reports a facile approach using a nanoporous material, zeolitic imidazolate framework-8 (ZIF-8), as an encapsulant for preserving the prototypic protein therapeutic, insulin, against different harsh conditions that may be encountered during storage, formulation, and transport, including elevated temperatures, mechanical agitation, and organic solvent. Both immunoassay and spectroscopy analyses demonstrate the preserved chemical stability and structural integrity of insulin offered by the ZIF-8 encapsulation. Biological activity of ZIF-8-preserved insulin after storage under accelerated degradation conditions (i.e., 40 °C) is evaluated in vivo using a diabetic mouse model, and shows comparable bioactivity to refrigeration-stored insulin (-20 °C). It is also demonstrated that ZIF-8-preserved insulin has low cytotoxicity in vitro and does not cause side effects in vivo. Furthermore, ZIF-8 residue can be completely removed by a simple purification step before insulin administration. This biopreservation approach is potentially applicable to diverse protein therapeutics, thus extending the benefits of advanced biologics to resource-limited settings and underserved populations/regions.
Collapse
Affiliation(s)
- Congzhou Wang
- Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University in St. Louis, MO, 63130, USA
| | - Gail Sudlow
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Zheyu Wang
- Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University in St. Louis, MO, 63130, USA
| | - Sisi Cao
- Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University in St. Louis, MO, 63130, USA
| | - Qisheng Jiang
- Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University in St. Louis, MO, 63130, USA
| | - Alicia Neiner
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Jeremiah J. Morrissey
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
- Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Evan. D. Kharasch
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
- Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO, 63110, USA
- The Center for Clinical Pharmacology, St. Louis College of Pharmacy and Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Anesthesiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Samuel Achilefu
- Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO, 63110, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Srikanth Singamaneni
- Department of Mechanical Engineering and Materials Science, Institute of Materials Science and Engineering, Washington University in St. Louis, MO, 63130, USA
- Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO, 63110, USA
| |
Collapse
|
22
|
Erak M, Bellmann-Sickert K, Els-Heindl S, Beck-Sickinger AG. Peptide chemistry toolbox - Transforming natural peptides into peptide therapeutics. Bioorg Med Chem 2018; 26:2759-2765. [PMID: 29395804 DOI: 10.1016/j.bmc.2018.01.012] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/09/2018] [Accepted: 01/18/2018] [Indexed: 01/27/2023]
Abstract
The development of solid phase peptide synthesis has released tremendous opportunities for using synthetic peptides in medicinal applications. In the last decades, peptide therapeutics became an emerging market in pharmaceutical industry. The need for synthetic strategies in order to improve peptidic properties, such as longer half-life, higher bioavailability, increased potency and efficiency is accordingly rising. In this mini-review, we present a toolbox of modifications in peptide chemistry for overcoming the main drawbacks during the transition from natural peptides to peptide therapeutics. Modifications at the level of the peptide backbone, amino acid side chains and higher orders of structures are described. Furthermore, we are discussing the future of peptide therapeutics development and their impact on the pharmaceutical market.
Collapse
Affiliation(s)
- Miloš Erak
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Bruederstrasse 34, 04103 Leipzig, Germany
| | - Kathrin Bellmann-Sickert
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Bruederstrasse 34, 04103 Leipzig, Germany
| | - Sylvia Els-Heindl
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Bruederstrasse 34, 04103 Leipzig, Germany
| | - Annette G Beck-Sickinger
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Bruederstrasse 34, 04103 Leipzig, Germany.
| |
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Glidden MD, Aldabbagh K, Phillips NB, Carr K, Chen YS, Whittaker J, Phillips M, Wickramasinghe NP, Rege N, Swain M, Peng Y, Yang Y, Lawrence MC, Yee VC, Ismail-Beigi F, Weiss MA. An ultra-stable single-chain insulin analog resists thermal inactivation and exhibits biological signaling duration equivalent to the native protein. J Biol Chem 2017; 293:47-68. [PMID: 29114035 DOI: 10.1074/jbc.m117.808626] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/12/2017] [Indexed: 12/12/2022] Open
Abstract
Thermal degradation of insulin complicates its delivery and use. Previous efforts to engineer ultra-stable analogs were confounded by prolonged cellular signaling in vivo, of unclear safety and complicating mealtime therapy. We therefore sought an ultra-stable analog whose potency and duration of action on intravenous bolus injection in diabetic rats are indistinguishable from wild-type (WT) insulin. Here, we describe the structure, function, and stability of such an analog, a 57-residue single-chain insulin (SCI) with multiple acidic substitutions. Cell-based studies revealed native-like signaling properties with negligible mitogenic activity. Its crystal structure, determined as a novel zinc-free hexamer at 2.8 Å, revealed a native insulin fold with incomplete or absent electron density in the C domain; complementary NMR studies are described in the accompanying article. The stability of the analog (ΔGU 5.0(±0.1) kcal/mol at 25 °C) was greater than that of WT insulin (3.3(±0.1) kcal/mol). On gentle agitation, the SCI retained full activity for >140 days at 45 °C and >48 h at 75 °C. These findings indicate that marked resistance to thermal inactivation in vitro is compatible with native duration of activity in vivo Further, whereas WT insulin forms large and heterogeneous aggregates above the standard 0.6 mm pharmaceutical strength, perturbing the pharmacokinetic properties of concentrated formulations, dynamic light scattering, and size-exclusion chromatography revealed only limited SCI self-assembly and aggregation in the concentration range 1-7 mm Such a combination of favorable biophysical and biological properties suggests that SCIs could provide a global therapeutic platform without a cold chain.
Collapse
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
| | - Khadijah Aldabbagh
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - 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
| | - Yen-Shan Chen
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Jonathan Whittaker
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Manijeh Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | | | - Nischay Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Mamuni Swain
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yi Peng
- Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106
| | - Yanwu Yang
- Department of Biochemistry, 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
| | - Vivien C Yee
- 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 A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106.
| |
Collapse
|
25
|
Hossain MA, Bathgate RAD. Challenges in the design of insulin and relaxin/insulin-like peptide mimetics. Bioorg Med Chem 2017; 26:2827-2841. [PMID: 28988628 DOI: 10.1016/j.bmc.2017.09.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/19/2017] [Accepted: 09/19/2017] [Indexed: 12/20/2022]
Abstract
Peptidomimetics are designed to overcome the poor pharmacokinetics and pharmacodynamics associated with the native peptide or protein on which they are based. The design of peptidomimetics starts from developing structure-activity relationships of the native ligand-target pair that identify the key residues that are responsible for the biological effect of the native peptide or protein. Then minimization of the structure and introduction of constraints are applied to create the core active site that can interact with the target with high affinity and selectivity. Developing peptidomimetics is not trivial and often challenging, particularly when peptides' interaction mechanism with their target is complex. This review will discuss the challenges of developing peptidomimetics of therapeutically important insulin superfamily peptides, particularly those which have two chains (A and B) and three disulfide bonds and whose receptors are known, namely insulin, H2 relaxin, H3 relaxin, INSL3 and INSL5.
Collapse
Affiliation(s)
- Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia; School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Ross A D Bathgate
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC 3010, Australia.
| |
Collapse
|
26
|
Wu X, Huang YH, Kaas Q, Harvey PJ, Wang CK, Tae HS, Adams DJ, Craik DJ. Backbone cyclization of analgesic conotoxin GeXIVA facilitates direct folding of the ribbon isomer. J Biol Chem 2017; 292:17101-17112. [PMID: 28851841 DOI: 10.1074/jbc.m117.808386] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Indexed: 12/20/2022] Open
Abstract
Conotoxin GeXIVA inhibits the α9α10 nicotinic acetylcholine receptor (nAChR) and is analgesic in animal models of pain. α-Conotoxins have four cysteines that can have three possible disulfide connectivities: globular (CysI-CysIII and CysII-CysIV), ribbon (CysI-CysIV and CysII-CysIII), or bead (CysI-CysII and CysIII-CysIV). Native α-conotoxins preferably adopt the globular connectivity, and previous studies of α-conotoxins have focused on the globular isomers as the ribbon and bead isomers typically have lower potency at nAChRs than the globular form. A recent report showed that the bead and ribbon isomers of GeXIVA are more potent than the globular isomer, with low nanomolar half-maximal inhibitory concentrations (IC50). Despite this high potency, the therapeutic potential of GeXIVA is limited, because like most peptides, it is susceptible to proteolytic degradation and is challenging to synthesize in high yield. Here we used backbone cyclization as a strategy to improve the folding yield as well as increase the serum stability of ribbon GeXIVA while preserving activity at the α9α10 nAChR. Specifically, cyclization of ribbon GeXIVA with a two-residue linker maintained the biological activity at the human α9α10 nAChR and improved stability in human serum. Short linkers led to selective formation of the ribbon disulfide isomer without requiring orthogonal protection. Overall, this study highlights the value of backbone cyclization in directing folding, improving yields, and stabilizing conotoxins with therapeutic potential.
Collapse
Affiliation(s)
- Xiaosa Wu
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Yen-Hua Huang
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Quentin Kaas
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Peta J Harvey
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Conan K Wang
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| | - Han-Shen Tae
- the Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - David J Adams
- the Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - David J Craik
- From the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia and
| |
Collapse
|
27
|
Abstract
PURPOSE OF REVIEW The complexity of modern insulin-based therapy for type I and type II diabetes mellitus and the risks associated with excursions in blood-glucose concentration (hyperglycemia and hypoglycemia) have motivated the development of 'smart insulin' technologies (glucose-responsive insulin, GRI). Such analogs or delivery systems are entities that provide insulin activity proportional to the glycemic state of the patient without external monitoring by the patient or healthcare provider. The present review describes the relevant historical background to modern GRI technologies and highlights three distinct approaches: coupling of continuous glucose monitoring (CGM) to deliver devices (algorithm-based 'closed-loop' systems), glucose-responsive polymer encapsulation of insulin, and molecular modification of insulin itself. RECENT FINDINGS Recent advances in GRI research utilizing each of the three approaches are illustrated; these include newly developed algorithms for CGM-based insulin delivery systems, glucose-sensitive modifications of existing clinical analogs, newly developed hypoxia-sensitive polymer matrices, and polymer-encapsulated, stem-cell-derived pancreatic β cells. SUMMARY Although GRI technologies have yet to be perfected, the recent advances across several scientific disciplines that are described in this review have provided a path towards their clinical implementation.
Collapse
Affiliation(s)
- Nischay K. Rege
- Department of Biochemistry and Medical Scientist Training Program, Case Western Reserve University
| | | | - Michael A. Weiss
- Chairman of Institute for Therapeutic Protein Design, Departments of Biomedical Engineering, Biochemistry, and Medicine
| |
Collapse
|
28
|
Secretory expression and surface display of a new and biologically active single-chain insulin (SCI-59) analog by lactic acid bacteria. Appl Microbiol Biotechnol 2017; 101:3259-3271. [DOI: 10.1007/s00253-017-8125-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 12/31/2022]
|
29
|
Karas JA, Patil NA, Tailhades J, Sani MA, Scanlon DB, Forbes BE, Gardiner J, Separovic F, Wade JD, Hossain MA. Total Chemical Synthesis of an Intra-A-Chain Cystathionine Human Insulin Analogue with Enhanced Thermal Stability. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- John A. Karas
- The Florey Institute of Neuroscience and Mental Health; The University of Melbourne; Melbourne VIC 3010 Australia
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
- CSIRO; Materials Science and Engineering; Clayton VIC 3010 Australia
| | - Nitin A. Patil
- The Florey Institute of Neuroscience and Mental Health; The University of Melbourne; Melbourne VIC 3010 Australia
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
| | - Julien Tailhades
- The Florey Institute of Neuroscience and Mental Health; The University of Melbourne; Melbourne VIC 3010 Australia
| | - Marc-Antoine Sani
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
| | - Denis B. Scanlon
- Department of Chemistry; University of Adelaide; Adelaide SA 5005 Australia
| | - Briony E. Forbes
- School of Medicine; Flinders University; Bedford Park SA 5042 Australia
| | - James Gardiner
- CSIRO; Materials Science and Engineering; Clayton VIC 3010 Australia
| | - Frances Separovic
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
| | - John D. Wade
- The Florey Institute of Neuroscience and Mental Health; The University of Melbourne; Melbourne VIC 3010 Australia
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health; The University of Melbourne; Melbourne VIC 3010 Australia
- School of Chemistry; Bio21 Institute; University of Melbourne; Melbourne VIC 3010 Australia
| |
Collapse
|
30
|
Karas JA, Patil NA, Tailhades J, Sani MA, Scanlon DB, Forbes BE, Gardiner J, Separovic F, Wade JD, Hossain MA. Total Chemical Synthesis of an Intra-A-Chain Cystathionine Human Insulin Analogue with Enhanced Thermal Stability. Angew Chem Int Ed Engl 2016; 55:14743-14747. [PMID: 27761974 DOI: 10.1002/anie.201607101] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Indexed: 12/17/2022]
Abstract
Despite recent advances in the treatment of diabetes mellitus, storage of insulin formulations at 4 °C is still necessary to minimize chemical degradation. This is problematic in tropical regions where reliable refrigeration is not ubiquitous. Some degradation byproducts are caused by disulfide shuffling of cystine that leads to covalently bonded oligomers. Consequently we examined the utility of the non-reducible cystine isostere, cystathionine, within the A-chain. Reported herein is an efficient method for forming this mimic using simple monomeric building blocks. The intra-A-chain cystathionine insulin analogue was obtained in good overall yield, chemically characterized and demonstrated to possess native binding affinity for the insulin receptor isoform B. It was also shown to possess significantly enhanced thermal stability indicating potential application to next-generation insulin analogues.
Collapse
Affiliation(s)
- John A Karas
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.,School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia.,CSIRO, Materials Science and Engineering, Clayton, VIC, 3010, Australia
| | - Nitin A Patil
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.,School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Julien Tailhades
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Denis B Scanlon
- Department of Chemistry, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Briony E Forbes
- School of Medicine, Flinders University, Bedford Park, SA, 5042, Australia
| | - James Gardiner
- CSIRO, Materials Science and Engineering, Clayton, VIC, 3010, Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - John D Wade
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.,School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.,School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC, 3010, Australia
| |
Collapse
|
31
|
El Hage K, Bereau T, Jakobsen S, Meuwly M. Impact of Quadrupolar Electrostatics on Atoms Adjacent to the Sigma-Hole in Condensed-Phase Simulations. J Chem Theory Comput 2016; 12:3008-19. [PMID: 27158892 DOI: 10.1021/acs.jctc.6b00202] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Halogenation is one of the cases for which advanced molecular simulation methods are mandatory for quantitative and predictive studies. The present work provides a systematic investigation of the importance of higher-order multipoles on specific sites of halobenzenes, other than the halogen, for static and dynamic properties in condensed-phase simulations. For that purpose, solute-solvent interactions using point charge (PC), multipole (MTP), and hybrid point charge/multipole (HYB) electrostatic models are analyzed in regions of halogen bonding and extended to regions of π orbitals of phenyl carbons. Using molecular dynamics simulations and quantum chemical methods, it is found that the sigma-hole does not only affect the halogen and the carbon bound to it but its effect extends to the carbons adjacent to the CX bond. This effect increases with the magnitude of the positive potential of the sigma-hole. With the MTP and HYB3 models, all hydration free energies of the PhX compounds are reproduced within 0.1 kcal/mol. Analysis of pair distribution functions and hydration free energies of halogenated benzenes provides a microscopic explanation why "point charge"-based representations with off-site charges fail in reproducing thermodynamic properties of the sigma-hole. Application of the hybrid models to study protein-ligand binding demonstrates both their accuracy and computational efficiency.
Collapse
Affiliation(s)
- Krystel El Hage
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Tristan Bereau
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Sofie Jakobsen
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland.,Department of Chemistry, Aarhus University , Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Markus Meuwly
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| |
Collapse
|
32
|
Abstract
Insulin remains indispensable in the treatment of diabetes, but its use is hampered by its narrow therapeutic index. Although advances in peptide chemistry and recombinant DNA-based macromolecule synthesis have enabled the synthesis of structurally optimized insulin analogues, the growing epidemics of obesity and diabetes have emphasized the need for diabetes therapies that are more efficacious, safe and convenient. Accordingly, a broad set of drug candidates, targeting hyperglycaemia plus other disease abnormalities, is now progressing through the clinic. The development of an insulin therapy that is responsive to glucose concentration remains an ultimate goal, with initial prototypes now reaching the proof-of-concept stage. Simultaneously, the first alternatives to injectable delivery have progressed to registration.
Collapse
|
33
|
Vinther TN, Kjeldsen TB, Jensen KJ, Hubálek F. The road to the first, fully active and more stable human insulin variant with an additional disulfide bond. J Pept Sci 2015; 21:797-806. [DOI: 10.1002/psc.2822] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/14/2015] [Accepted: 08/19/2015] [Indexed: 12/21/2022]
Affiliation(s)
| | | | - Knud J. Jensen
- Faculty of Science, Department of Chemistry; University of Copenhagen; DK-1871 Frederiksberg Denmark
| | | |
Collapse
|
34
|
Adams JP, Holder AL, Catchpole B. Recombinant canine single chain insulin analogues: Insulin receptor binding capacity and ability to stimulate glucose uptake. Vet J 2014; 202:436-42. [DOI: 10.1016/j.tvjl.2014.09.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/24/2014] [Accepted: 09/29/2014] [Indexed: 10/24/2022]
|
35
|
Abstract
Biomolecules are the prime information processing elements of living matter. Most of these inanimate systems are polymers that compute their own structures and dynamics using as input seemingly random character strings of their sequence, following which they coalesce and perform integrated cellular functions. In large computational systems with finite interaction-codes, the appearance of conflicting goals is inevitable. Simple conflicting forces can lead to quite complex structures and behaviors, leading to the concept of frustration in condensed matter. We present here some basic ideas about frustration in biomolecules and how the frustration concept leads to a better appreciation of many aspects of the architecture of biomolecules, and especially how biomolecular structure connects to function by means of localized frustration. These ideas are simultaneously both seductively simple and perilously subtle to grasp completely. The energy landscape theory of protein folding provides a framework for quantifying frustration in large systems and has been implemented at many levels of description. We first review the notion of frustration from the areas of abstract logic and its uses in simple condensed matter systems. We discuss then how the frustration concept applies specifically to heteropolymers, testing folding landscape theory in computer simulations of protein models and in experimentally accessible systems. Studying the aspects of frustration averaged over many proteins provides ways to infer energy functions useful for reliable structure prediction. We discuss how frustration affects folding mechanisms. We review here how the biological functions of proteins are related to subtle local physical frustration effects and how frustration influences the appearance of metastable states, the nature of binding processes, catalysis and allosteric transitions. In this review, we also emphasize that frustration, far from being always a bad thing, is an essential feature of biomolecules that allows dynamics to be harnessed for function. In this way, we hope to illustrate how Frustration is a fundamental concept in molecular biology.
Collapse
|
36
|
Abstract
Insulin provides a classical model of a globular protein, yet how the hormone changes conformation to engage its receptor has long been enigmatic. Interest has focused on the C-terminal B-chain segment, critical for protective self-assembly in β cells and receptor binding at target tissues. Insight may be obtained from truncated "microreceptors" that reconstitute the primary hormone-binding site (α-subunit domains L1 and αCT). We demonstrate that, on microreceptor binding, this segment undergoes concerted hinge-like rotation at its B20-B23 β-turn, coupling reorientation of Phe(B24) to a 60° rotation of the B25-B28 β-strand away from the hormone core to lie antiparallel to the receptor's L1-β2 sheet. Opening of this hinge enables conserved nonpolar side chains (Ile(A2), Val(A3), Val(B12), Phe(B24), and Phe(B25)) to engage the receptor. Restraining the hinge by nonstandard mutagenesis preserves native folding but blocks receptor binding, whereas its engineered opening maintains activity at the price of protein instability and nonnative aggregation. Our findings rationalize properties of clinical mutations in the insulin family and provide a previously unidentified foundation for designing therapeutic analogs. We envisage that a switch between free and receptor-bound conformations of insulin evolved as a solution to conflicting structural determinants of biosynthesis and function.
Collapse
|
37
|
Kaur ZP, Ochman AR, Mayer JP, Gelfanov VM, DiMarchi RD. Discovery of high potency, single-chain insulin analogs with a shortened B-chain and nonpeptide linker. ACS Chem Biol 2013; 8:1822-9. [PMID: 23730814 DOI: 10.1021/cb4002624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of novel, single chain insulin analogs containing polyethylene glycol based connecting segments were synthesized by native chemical ligation and tested for biological activity. While the full length single chain insulin analogs exhibited low potency, deletion of amino acids B26-B30 unexpectedly generated markedly higher activity. This observation is unprecedented in all previous studies of single chain insulin analogs and is consistent with the presumption that in the native hormone this sequence must translocate to achieve high potency insulin receptor interaction. Optimization of the sequence yielded an insulin analog with potency and selectivity comparable to that of native insulin. These results establish a basis for discovery of novel higher potency, single chain insulin analogs of shortened length.
Collapse
Affiliation(s)
- Zachary P. Kaur
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United
States
| | | | - John P. Mayer
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United
States
| | - Vasily M. Gelfanov
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United
States
| | - Richard D. DiMarchi
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United
States
| |
Collapse
|
38
|
Vashisth H, Abrams CF. All-atom structural models of insulin binding to the insulin receptor in the presence of a tandem hormone-binding element. Proteins 2013; 81:1017-30. [PMID: 23348915 DOI: 10.1002/prot.24255] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 12/11/2012] [Accepted: 01/04/2013] [Indexed: 11/10/2022]
Abstract
Insulin regulates blood glucose levels in higher organisms by binding to and activating insulin receptor (IR), a constitutively homodimeric glycoprotein of the receptor tyrosine kinase (RTK) superfamily. Therapeutic efforts in treating diabetes have been significantly impeded by the absence of structural information on the activated form of the insulin/IR complex. Mutagenesis and photo-crosslinking experiments and structural information on insulin and apo-IR strongly suggest that the dual-chain insulin molecule, unlike the related single-chain insulin-like growth factors, binds to IR in a very different conformation than what is displayed in storage forms of the hormone. In particular, hydrophobic residues buried in the core of the folded insulin molecule engage the receptor. There is also the possibility of plasticity in the receptor structure based on these data, which may in part be due to rearrangement of the so-called CT-peptide, a tandem hormone-binding element of IR. These possibilities provide opportunity for large-scale molecular modeling to contribute to our understanding of this system. Using various atomistic simulation approaches, we have constructed all-atom structural models of hormone/receptor complexes in the presence of CT in its crystallographic position and a thermodynamically favorable displaced position. In the "displaced-CT" complex, many more insulin-receptor contacts suggested by experiments are satisfied, and our simulations also suggest that R-insulin potentially represents the receptor-bound form of hormone. The results presented in this work have further implications for the design of receptor-specific agonists/antagonists.
Collapse
Affiliation(s)
- Harish Vashisth
- Department of Chemistry and Biophysics Program, University of Michigan, Ann Arbor, Michigan, USA.
| | | |
Collapse
|
39
|
Vinther TN, Norrman M, Ribel U, Huus K, Schlein M, Steensgaard DB, Pedersen TÅ, Pettersson I, Ludvigsen S, Kjeldsen T, Jensen KJ, Hubálek F. Insulin analog with additional disulfide bond has increased stability and preserved activity. Protein Sci 2013; 22:296-305. [PMID: 23281053 DOI: 10.1002/pro.2211] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/04/2012] [Accepted: 12/07/2012] [Indexed: 11/10/2022]
Abstract
Insulin is a key hormone controlling glucose homeostasis. All known vertebrate insulin analogs have a classical structure with three 100% conserved disulfide bonds that are essential for structural stability and thus the function of insulin. It might be hypothesized that an additional disulfide bond may enhance insulin structural stability which would be highly desirable in a pharmaceutical use. To address this hypothesis, we designed insulin with an additional interchain disulfide bond in positions A10/B4 based on Cα-Cα distances, solvent exposure, and side-chain orientation in human insulin (HI) structure. This insulin analog had increased affinity for the insulin receptor and apparently augmented glucodynamic potency in a normal rat model compared with HI. Addition of the disulfide bond also resulted in a 34.6°C increase in melting temperature and prevented insulin fibril formation under high physical stress even though the C-terminus of the B-chain thought to be directly involved in fibril formation was not modified. Importantly, this analog was capable of forming hexamer upon Zn addition as typical for wild-type insulin and its crystal structure showed only minor deviations from the classical insulin structure. Furthermore, the additional disulfide bond prevented this insulin analog from adopting the R-state conformation and thus showing that the R-state conformation is not a prerequisite for binding to insulin receptor as previously suggested. In summary, this is the first example of an insulin analog featuring a fourth disulfide bond with increased structural stability and retained function.
Collapse
Affiliation(s)
- Tine N Vinther
- Diabetes Research Unit, Novo Nordisk A/S, Novo Nordisk Park, Måløv DK-2760, Denmark
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Phillips NB, Whittaker J, Ismail-Beigi F, Weiss MA. Insulin fibrillation and protein design: topological resistance of single-chain analogs to thermal degradation with application to a pump reservoir. J Diabetes Sci Technol 2012; 6:277-88. [PMID: 22538136 PMCID: PMC3380768 DOI: 10.1177/193229681200600210] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Insulin is susceptible to thermal fibrillation, a misfolding process that leads to nonnative cross-β assembly analogous to pathological amyloid deposition. Pharmaceutical formulations are ordinarily protected from such degradation by sequestration of the susceptible monomer within native protein assemblies. With respect to the safety and efficacy of insulin pumps, however, this strategy imposes an intrinsic trade-off between pharmacokinetic goals (rapid absorption and clearance) and the requisite physical properties of a formulation (prolonged shelf life and stability within the reservoir). Available rapid-acting formulations are suboptimal in both respects; susceptibility to fibrillation is exacerbated even as absorption is delayed relative to the ideal specifications of a closed-loop system. To circumvent this molecular trade-off, we exploited structural models of insulin fibrils and amyloidogenic intermediates to define an alternative protective mechanism. Single-chain insulin (SCI) analogs were shown to be refractory to thermal fibrillation with maintenance of biological activity for more than 3 months under conditions that promote the rapid fibrillation and inactivation of insulin. The essential idea exploits an intrinsic incompatibility between SCI topology and the geometry of cross-β assembly. A peptide tether was thus interposed between the A- and B-chains whose length was (a) sufficiently long to provide the "play" needed for induced fit of the hormone on receptor binding and yet (b) sufficiently short to impose a topological barrier to fibrillation. Our findings suggest that ultrastable monomeric SCI analogs may be formulated without protective self-assembly and so permit simultaneous optimization of pharmacokinetics and reservoir life.
Collapse
Affiliation(s)
- Nelson B. Phillips
- Department of Biochemistry, Case Western Reserve University School of MedicineCleveland, Ohio
| | - Jonathan Whittaker
- Department of Biochemistry, Case Western Reserve University School of MedicineCleveland, Ohio
| | - Faramarz Ismail-Beigi
- Department of Medicine, Case Western Reserve University School of MedicineCleveland, Ohio
| | - Michael A. Weiss
- Department of Biochemistry, Case Western Reserve University School of MedicineCleveland, Ohio
- Department of Medicine, Case Western Reserve University School of MedicineCleveland, Ohio
- Biomedical Engineering, Case Western Reserve University School of MedicineCleveland, Ohio
| |
Collapse
|
41
|
Berenson DF, Weiss AR, Wan ZL, Weiss MA. Insulin analogs for the treatment of diabetes mellitus: therapeutic applications of protein engineering. Ann N Y Acad Sci 2011; 1243:E40-E54. [PMID: 22641195 PMCID: PMC3360579 DOI: 10.1111/j.1749-6632.2012.06468.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The engineering of insulin analogs represents a triumph of structure-based protein design. A framework has been provided by structures of insulin hexamers. Containing a zinc-coordinated trimer of dimers, such structures represent a storage form of the active insulin monomer. Initial studies focused on destabilization of subunit interfaces. Because disassembly facilitates capillary absorption, such targeted destabilization enabled development of rapid-acting insulin analogs. Converse efforts were undertaken to stabilize the insulin hexamer and promote higher-order self-assembly within the subcutaneous depot toward the goal of enhanced basal glycemic control with reduced risk of hypoglycemia. Current products either operate through isoelectric precipitation (insulin glargine, the active component of Lantus(®); Sanofi-Aventis) or employ an albumin-binding acyl tether (insulin detemir, the active component of Levemir(®); Novo-Nordisk). To further improve pharmacokinetic properties, modified approaches are presently under investigation. Novel strategies have recently been proposed based on subcutaneous supramolecular assembly coupled to (a) large-scale allosteric reorganization of the insulin hexamer (the TR transition), (b) pH-dependent binding of zinc ions to engineered His-X(3)-His sites at hexamer surfaces, or (c) the long-range vision of glucose-responsive polymers for regulated hormone release. Such designs share with wild-type insulin and current insulin products a susceptibility to degradation above room temperature, and so their delivery, storage, and use require the infrastructure of an affluent society. Given the global dimensions of the therapeutic supply chain, we envisage that concurrent engineering of ultra-stable protein analog formulations would benefit underprivileged patients in the developing world.
Collapse
Affiliation(s)
- Daniel F. Berenson
- Department of Molecular Biophysics and Biochemistry Yale University. New Haven, CT
| | - Allison R. Weiss
- National Institute of Diabetes, Digestive and Kidney Diseases National Institutes of Health, Bethesda, MD
| | - Zhu-li Wan
- Departments of Biochemistry, Biomedical Engineering and Medicine, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Michael A. Weiss
- Departments of Biochemistry, Biomedical Engineering and Medicine, Case Western Reserve University School of Medicine, Cleveland, OH
| |
Collapse
|
42
|
Abstract
Insulin is a hormone that is essential for regulating energy storage and glucose metabolism in the body. Insulin in liver, muscle, and fat tissues stimulates the cell to take up glucose from blood and store it as glycogen in liver and muscle. Failure of insulin control causes diabetes mellitus (DM). Insulin is the unique medicine to treat some forms of DM. The population of diabetics has dramatically increased over the past two decades, due to high absorption of carbohydrates (or fats and proteins), lack of physical exercise, and development of new diagnostic techniques. At present, the two largest developing countries (India and China) and the largest developed country (United States) represent the top three countries in terms of diabetic population. Insulin is a small protein, but contains almost all structural features typical of proteins: α-helix, β-sheet, β-turn, high order assembly, allosteric T®R-transition, and conformational changes in amyloidal fibrillation. More than ten years' efforts on studying insulin disulfide intermediates by NMR have enabled us to decipher the whole picture of insulin folding coupled to disulfide pairing, especially at the initial stage that forms the nascent peptide. Two structural switches are also known to regulate insulin binding to receptors and progress has been made to identify the residues involved in binding. However, resolving the complex structure of insulin and its receptor remains a challenge in insulin research. Nevertheless, the accumulated knowledge of insulin structure has allowed us to specifically design a new ultra-stable and active single-chain insulin analog (SCI-57), and provides a novel way to design super-stable, fast-acting and cheaper insulin formulations for DM patients. Continuing this long journey of insulin study will benefit basic research in proteins and in pharmaceutical therapy.
Collapse
Affiliation(s)
- Qingxin Hua
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106-4935, USA.
| |
Collapse
|
43
|
Ng DT, Sarkar CA. Nisin-inducible secretion of a biologically active single-chain insulin analog by Lactococcus lactis NZ9000. Biotechnol Bioeng 2011; 108:1987-96. [DOI: 10.1002/bit.23130] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 01/25/2011] [Accepted: 03/03/2011] [Indexed: 12/12/2022]
|
44
|
Sommese RF, Sivaramakrishnan S, Baldwin RL, Spudich JA. Helicity of short E-R/K peptides. Protein Sci 2011; 19:2001-5. [PMID: 20669185 DOI: 10.1002/pro.469] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Understanding the secondary structure of peptides is important in protein folding, enzyme function, and peptide-based drug design. Previous studies of synthetic Ala-based peptides (>12 a.a.) have demonstrated the role for charged side chain interactions involving Glu/Lys or Glu/Arg spaced three (i, i + 3) or four (i, i + 4) residues apart. The secondary structure of short peptides (<9 a.a.), however, has not been investigated. In this study, the effect of repetitive Glu/Lys or Glu/Arg side chain interactions, giving rise to E-R/K helices, on the helicity of short peptides was examined using circular dichroism. Short E-R/K-based peptides show significant helix content. Peptides containing one or more E-R interactions display greater helicity than those with similar E-K interactions. Significant helicity is achieved in Arg-based E-R/K peptides eight, six, and five amino acids long. In these short peptides, each additional i + 3 and i + 4 salt bridge has substantial contribution to fractional helix content. The E-R/K peptides exhibit a strongly linear melt curve indicative of noncooperative folding. The significant helicity of these short peptides with predictable dependence on number, position, and type of side chain interactions makes them an important consideration in peptide design.
Collapse
Affiliation(s)
- Ruth F Sommese
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | |
Collapse
|
45
|
Abstract
We have exploited a prandial insulin analog to elucidate the underlying structure and dynamics of insulin as a monomer in solution. A model was provided by insulin lispro (the active component of Humalog(®); Eli Lilly and Co.). Whereas NMR-based modeling recapitulated structural relationships of insulin crystals (T-state protomers), dynamic anomalies were revealed by amide-proton exchange kinetics in D(2)O. Surprisingly, the majority of hydrogen bonds observed in crystal structures are only transiently maintained in solution, including key T-state-specific inter-chain contacts. Long-lived hydrogen bonds (as defined by global exchange kinetics) exist only at a subset of four α-helical sites (two per chain) flanking an internal disulfide bridge (cystine A20-B19); these sites map within the proposed folding nucleus of proinsulin. The anomalous flexibility of insulin otherwise spans its active surface and may facilitate receptor binding. Because conformational fluctuations promote the degradation of pharmaceutical formulations, we envisage that "dynamic re-engineering" of insulin may enable design of ultra-stable formulations for humanitarian use in the developing world.
Collapse
Affiliation(s)
- Qing-Xin Hua
- Department of Biochemistry, School of Medicine, Case Western Reserve UniversityCleveland, OH, USA
| | - Wenhua Jia
- Department of Biochemistry, School of Medicine, Case Western Reserve UniversityCleveland, OH, USA
| | - Michael A. Weiss
- Department of Biochemistry, School of Medicine, Case Western Reserve UniversityCleveland, OH, USA
- *Correspondence: Michael A. Weiss, Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue – Wood W436, Cleveland, OH 44106-4935, USA. e-mail:
| |
Collapse
|
46
|
Andersen AS, Palmqvist E, Bang S, Shaw AC, Hubalek F, Ribel U, Hoeg-Jensen T. Backbone cyclic insulin. J Pept Sci 2010; 16:473-9. [PMID: 20641002 DOI: 10.1002/psc.1264] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Backbone cyclic insulin was designed and prepared by reverse proteolysis in partial organic solvent of a single-chain precursor expressed in yeast. The precursor contains two loops to bridge the two chains of native insulin. The cyclisation method uses Achromobacter lyticus protease and should be generally applicable to proteins with C-terminal lysine and proximal N-terminal. The presence of the ring-closing bond and the native insulin disulfide patterns were documented by LC-MS peptide maps. The cyclic insulin was shown to be inert towards degradation by CPY, but was somewhat labile towards chymotrypsin. Intravenous administration of the cyclic insulin to Wistar rats showed the compounds to be equipotent to HI despite much lower insulin receptor affinity.
Collapse
Affiliation(s)
- Asser S Andersen
- Protein Expression, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark
| | | | | | | | | | | | | |
Collapse
|
47
|
Yang Y, Petkova A, Huang K, Xu B, Hua QX, Ye IJ, Chu YC, Hu SQ, Phillips NB, Whittaker J, Ismail-Beigi F, Mackin RB, Katsoyannis PG, Tycko R, Weiss MA. An Achilles' heel in an amyloidogenic protein and its repair: insulin fibrillation and therapeutic design. J Biol Chem 2010; 285:10806-21. [PMID: 20106984 PMCID: PMC2856287 DOI: 10.1074/jbc.m109.067850] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/19/2010] [Indexed: 11/06/2022] Open
Abstract
Insulin fibrillation provides a model for a broad class of amyloidogenic diseases. Conformational distortion of the native monomer leads to aggregation-coupled misfolding. Whereas beta-cells are protected from proteotoxicity by hexamer assembly, fibrillation limits the storage and use of insulin at elevated temperatures. Here, we have investigated conformational distortions of an engineered insulin monomer in relation to the structure of an insulin fibril. Anomalous (13)C NMR chemical shifts and rapid (15)N-detected (1)H-(2)H amide-proton exchange were observed in one of the three classical alpha-helices (residues A1-A8) of the hormone, suggesting a conformational equilibrium between locally folded and unfolded A-chain segments. Whereas hexamer assembly resolves these anomalies in accordance with its protective role, solid-state (13)C NMR studies suggest that the A-chain segment participates in a fibril-specific beta-sheet. Accordingly, we investigated whether helicogenic substitutions in the A1-A8 segment might delay fibrillation. Simultaneous substitution of three beta-branched residues (Ile(A2) --> Leu, Val(A3) --> Leu, and Thr(A8) --> His) yielded an analog with reduced thermodynamic stability but marked resistance to fibrillation. Whereas amide-proton exchange in the A1-A8 segment remained rapid, (13)Calpha chemical shifts exhibited a more helical pattern. This analog is essentially without activity, however, as Ile(A2) and Val(A3) define conserved receptor contacts. To obtain active analogs, substitutions were restricted to A8. These analogs exhibit high receptor-binding affinity; representative potency in a rodent model of diabetes mellitus was similar to wild-type insulin. Although (13)Calpha chemical shifts remain anomalous, significant protection from fibrillation is retained. Together, our studies define an "Achilles' heel" in a globular protein whose repair may enhance the stability of pharmaceutical formulations and broaden their therapeutic deployment in the developing world.
Collapse
Affiliation(s)
- Yanwu Yang
- From the Departments of Biochemistry and
| | - Aneta Petkova
- the Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0520
| | - Kun Huang
- From the Departments of Biochemistry and
| | - Bin Xu
- From the Departments of Biochemistry and
| | | | - I-Ju Ye
- From the Departments of Biochemistry and
| | - Ying-Chi Chu
- the Department of Pharmacology and Biological Chemistry, Mt. Sinai School of Medicine, New York University, New York, New York 10029, and
| | | | | | | | | | - Robert B. Mackin
- the Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178
| | - Panayotis G. Katsoyannis
- the Department of Pharmacology and Biological Chemistry, Mt. Sinai School of Medicine, New York University, New York, New York 10029, and
| | - Robert Tycko
- the Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0520
| | - Michael A. Weiss
- From the Departments of Biochemistry and
- Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| |
Collapse
|
48
|
Structural resolution of a tandem hormone-binding element in the insulin receptor and its implications for design of peptide agonists. Proc Natl Acad Sci U S A 2010; 107:6771-6. [PMID: 20348418 DOI: 10.1073/pnas.1001813107] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The C-terminal segment of the human insulin receptor alpha-chain (designated alphaCT) is critical to insulin binding as has been previously demonstrated by alanine scanning mutagenesis and photo-cross-linking. To date no information regarding the structure of this segment within the receptor has been available. We employ here the technique of thermal-factor sharpening to enhance the interpretability of the electron-density maps associated with the earlier crystal structure of the human insulin receptor ectodomain. The alphaCT segment is now resolved as being engaged with the central beta-sheet of the first leucine-rich repeat (L1) domain of the receptor. The segment is alpha-helical in conformation and extends 11 residues N-terminal of the classical alphaCT segment boundary originally defined by peptide mapping. This tandem structural element (alphaCT-L1) thus defines the intact primary insulin-binding surface of the apo-receptor. The structure, together with isothermal titration calorimetry data of mutant alphaCT peptides binding to an insulin minireceptor, leads to the conclusion that putative "insulin-mimetic" peptides in the literature act at least in part as mimics of the alphaCT segment as well as of insulin. Photo-cross-linking by novel bifunctional insulin derivatives demonstrates that the interaction of insulin with the alphaCT segment and the L1 domain occurs in trans, i.e., these components of the primary binding site are contributed by alternate alpha-chains within the insulin receptor homodimer. The tandem structural element defines a new target for the design of insulin agonists for the treatment of diabetes mellitus.
Collapse
|
49
|
Ward CW, Lawrence MC. Ligand-induced activation of the insulin receptor: a multi-step process involving structural changes in both the ligand and the receptor. Bioessays 2009; 31:422-34. [PMID: 19274663 DOI: 10.1002/bies.200800210] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Current models of insulin binding to the insulin receptor (IR) propose (i) that there are two binding sites on the surface of insulin which engage with two binding sites on the receptor and (ii) that ligand binding involves structural changes in both the ligand and the receptor. Many of the features of insulin binding to its receptor, namely B-chain helix interactions with the leucine-rich repeat domain and A-chain residue interactions with peptide loops from another part of the receptor, are also seen in models of relaxin and insulin-like peptide 3 binding to their receptors. We show that these principles can likely be extended to the group of mimetic peptides described by Schäffer and coworkers, which are reported to have no sequence identity with insulin. This review summarizes our current understanding of ligand-induced activation of the IR and highlights the key issues that remain to be addressed.
Collapse
Affiliation(s)
- Colin W Ward
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
| | | |
Collapse
|
50
|
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.
Collapse
Affiliation(s)
- Zhihe Kuang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | | | | | | | | | | |
Collapse
|