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Weil-Ktorza O, Dhayalan B, Chen YS, Weiss MA, Metanis N. Se-Glargine: Chemical Synthesis of a Basal Insulin Analogue Stabilized by an Internal Diselenide Bridge. Chembiochem 2024; 25:e202300818. [PMID: 38149322 DOI: 10.1002/cbic.202300818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/21/2023] [Accepted: 12/24/2023] [Indexed: 12/28/2023]
Abstract
Insulin has long provided a model for studies of protein folding and stability, enabling enhanced treatment of diabetes mellitus via analogue design. We describe the chemical synthesis of a basal insulin analogue stabilized by substitution of an internal cystine (A6-A11) by a diselenide bridge. The studies focused on insulin glargine (formulated as Lantus® and Toujeo®; Sanofi). Prepared at pH 4 in the presence of zinc ions, glargine exhibits a shifted isoelectric point due to a basic B chain extension (ArgB31 -ArgB32 ). Subcutaneous injection leads to pH-dependent precipitation of a long-lived depot. Pairwise substitution of CysA6 and CysA11 by selenocysteine was effected by solid-phase peptide synthesis; the modified A chain also contained substitution of AsnA21 by Gly, circumventing acid-catalyzed deamidation. Although chain combination of native glargine yielded negligible product, in accordance with previous synthetic studies, the pairwise selenocysteine substitution partially rescued this reaction: substantial product was obtained through repeated combination, yielding a stabilized insulin analogue. This strategy thus exploited both (a) the unique redox properties of selenocysteine in protein folding and (b) favorable packing of an internal diselenide bridge in the native state, once achieved. Such rational optimization of protein folding and stability may be generalizable to diverse disulfide-stabilized proteins of therapeutic interest.
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Affiliation(s)
- Orit Weil-Ktorza
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Norman Metanis
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
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2
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Dhayalan B, Kent SBH, Fetter-Pruneda I. A Chemical Counterpart to the Resolution Step of Nature's Intein-Mediated Protein Splicing. ACS Chem Biol 2024; 19:9-14. [PMID: 38096499 PMCID: PMC10804359 DOI: 10.1021/acschembio.3c00590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 01/23/2024]
Abstract
In the course of an attempted total chemical synthesis of the ant insulin-like peptide-2 (ILP2) protein molecule, specific cleavage of a backbone peptide bond in a branched ester-linked polypeptide chain with concomitant peptide splicing was observed. The side reaction was investigated in model compounds. Here, we postulate a chemical mechanism for this novel polypeptide backbone cleavage reaction as a chemical counterpart to the resolution step of biochemical intein-mediated protein splicing.
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Affiliation(s)
- Balamurugan Dhayalan
- Department
of Chemistry, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Stephen B. H. Kent
- Department
of Chemistry, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Ingrid Fetter-Pruneda
- Laboratory
of Social Evolution and Behavior, The Rockefeller
University, 1230 York
Avenue, New York, New York 10065, United States
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Jarosinski MA, Chen YS, Varas N, Dhayalan B, Chatterjee D, Weiss MA. New Horizons: Next-Generation Insulin Analogues: Structural Principles and Clinical Goals. J Clin Endocrinol Metab 2022; 107:909-928. [PMID: 34850005 PMCID: PMC8947325 DOI: 10.1210/clinem/dgab849] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Indexed: 11/19/2022]
Abstract
Design of "first-generation" insulin analogues over the past 3 decades has provided pharmaceutical formulations with tailored pharmacokinetic (PK) and pharmacodynamic (PD) properties. Application of a molecular tool kit-integrating protein sequence, chemical modification, and formulation-has thus led to improved prandial and basal formulations for the treatment of diabetes mellitus. Although PK/PD changes were modest in relation to prior formulations of human and animal insulins, significant clinical advantages in efficacy (mean glycemia) and safety (rates of hypoglycemia) were obtained. Continuing innovation is providing further improvements to achieve ultrarapid and ultrabasal analogue formulations in an effort to reduce glycemic variability and optimize time in range. Beyond such PK/PD metrics, next-generation insulin analogues seek to exploit therapeutic mechanisms: glucose-responsive ("smart") analogues, pathway-specific ("biased") analogues, and organ-targeted analogues. Smart insulin analogues and delivery systems promise to mitigate hypoglycemic risk, a critical barrier to glycemic control, whereas biased and organ-targeted insulin analogues may better recapitulate physiologic hormonal regulation. In each therapeutic class considerations of cost and stability will affect use and global distribution. This review highlights structural principles underlying next-generation design efforts, their respective biological rationale, and potential clinical applications.
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Affiliation(s)
- Mark A Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Nicolás Varas
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA
- Correspondence: Michael A. Weiss, MD, PhD, Dept of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS 4053, Indianapolis, IN 46202-3082 USA.
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Dhayalan B, Glidden MD, Zaykov AN, Chen YS, Yang Y, Phillips NB, Ismail-Beigi F, Jarosinski MA, DiMarchi RD, Weiss MA. Peptide Model of the Mutant Proinsulin Syndrome. I. Design and Clinical Correlation. Front Endocrinol (Lausanne) 2022; 13:821069. [PMID: 35299972 PMCID: PMC8922534 DOI: 10.3389/fendo.2022.821069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/17/2022] [Indexed: 12/16/2022] Open
Abstract
The mutant proinsulin syndrome is a monogenic cause of diabetes mellitus due to toxic misfolding of insulin's biosynthetic precursor. Also designated mutant INS-gene induced diabetes of the young (MIDY), this syndrome defines molecular determinants of foldability in the endoplasmic reticulum (ER) of β-cells. Here, we describe a peptide model of a key proinsulin folding intermediate and variants containing representative clinical mutations; the latter perturb invariant core sites in native proinsulin (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser). The studies exploited a 49-residue single-chain synthetic precursor (designated DesDi), previously shown to optimize in vitro efficiency of disulfide pairing. Parent and variant peptides contain a single disulfide bridge (cystine B19-A20) to provide a model of proinsulin's first oxidative folding intermediate. The peptides were characterized by circular dichroism and redox stability in relation to effects of the mutations on (a) in vitro foldability of the corresponding insulin analogs and (b) ER stress induced in cell culture on expression of the corresponding variant proinsulins. Striking correlations were observed between peptide biophysical properties, degree of ER stress and age of diabetes onset (neonatal or adolescent). Our findings suggest that age of onset reflects the extent to which nascent structure is destabilized in proinsulin's putative folding nucleus. We envisage that such peptide models will enable high-resolution structural studies of key folding determinants and in turn permit molecular dissection of phenotype-genotype relationships in this monogenic diabetes syndrome. Our companion study (next article in this issue) employs two-dimensional heteronuclear NMR spectroscopy to define site-specific perturbations in the variant peptides.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Michael D. Glidden
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | | | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Nelson B. Phillips
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Faramarz Ismail-Beigi
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Mark A. Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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Yang Y, Glidden MD, Dhayalan B, Zaykov AN, Chen YS, Wickramasinghe NP, DiMarchi RD, Weiss MA. Peptide Model of the Mutant Proinsulin Syndrome. II. Nascent Structure and Biological Implications. Front Endocrinol (Lausanne) 2022; 13:821091. [PMID: 35299958 PMCID: PMC8922542 DOI: 10.3389/fendo.2022.821091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/21/2022] [Indexed: 11/13/2022] Open
Abstract
Toxic misfolding of proinsulin variants in β-cells defines a monogenic diabetes syndrome, designated mutant INS-gene induced diabetes of the young (MIDY). In our first study (previous article in this issue), we described a one-disulfide peptide model of a proinsulin folding intermediate and its use to study such variants. The mutations (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser) probe residues conserved among vertebrate insulins. In this companion study, we describe 1H and 1H-13C NMR studies of the peptides; key NMR resonance assignments were verified by synthetic 13C-labeling. Parent spectra retain nativelike features in the neighborhood of the single disulfide bridge (cystine B19-A20), including secondary NMR chemical shifts and nonlocal nuclear Overhauser effects. This partial fold engages wild-type side chains LeuB15, LeuA16 and PheB24 at the nexus of nativelike α-helices α1 and α3 (as defined in native proinsulin) and flanking β-strand (residues B24-B26). The variant peptides exhibit successive structural perturbations in order: parent (most organized) > SerB24 >> ProA16 > ProB15 (least organized). The same order pertains to (a) overall α-helix content as probed by circular dichroism, (b) synthetic yields of corresponding three-disulfide insulin analogs, and (c) ER stress induced in cell culture by corresponding mutant proinsulins. These findings suggest that this and related peptide models will provide a general platform for classification of MIDY mutations based on molecular mechanisms by which nascent disulfide pairing is impaired. We propose that the syndrome's variable phenotypic spectrum-onsets ranging from the neonatal period to later in childhood or adolescence-reflects structural features of respective folding intermediates.
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Affiliation(s)
- Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Michael D. Glidden
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Nalinda P. Wickramasinghe
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | | | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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6
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Dhayalan B, Weiss MA. Diabetes-Associated Mutations in Proinsulin Provide a "Molecular Rheostat" of Nascent Foldability. Curr Diab Rep 2022; 22:85-94. [PMID: 35119630 DOI: 10.1007/s11892-022-01447-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/04/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Diabetes mellitus (DM) due to toxic misfolding of proinsulin variants provides a monogenic model of endoplasmic reticulum (ER) stress. The mutant proinsulin syndrome (also designated MIDY; Mutant INS-gene-induced Diabetes of Youth or Maturity-onset diabetes of the young 10 (MODY10)) ordinarily presents as permanent neonatal-onset DM, but specific amino-acid substitutions may also present later in childhood or adolescence. This review highlights structural mechanisms of proinsulin folding as inferred from phenotype-genotype relationships. RECENT FINDINGS MIDY mutations most commonly add or remove a cysteine, leading to a variant polypeptide containing an odd number of thiol groups. Such variants are associated with aberrant intermolecular disulfide pairing, ER stress, and neonatal β-cell dysfunction. Non-cysteine-related (NCR) mutations (occurring in both the B and A domains of proinsulin) define distinct determinants of foldability and vary in severity. The range of ages of onset, therefore, reflects a "molecular rheostat" connecting protein biophysics to quality-control ER checkpoints. Because in most mammalian cell lines even wild-type proinsulin exhibits limited folding efficiency, molecular barriers to folding uncovered by NCR MIDY mutations may pertain to β-cell dysfunction in non-syndromic type 2 DM due to INS-gene overexpression in the face of peripheral insulin resistance. Recent studies of MIDY mutations and related NCR variants, combining molecular and cell-based approaches, suggest that proinsulin has evolved at the edge of non-foldability. Chemical protein synthesis promises to enable comparative studies of "non-foldable" proinsulin variants to define key steps in wild-type biosynthesis. Such studies may create opportunities for novel therapeutic approaches to non-syndromic type 2 DM.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
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7
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Jarosinski MA, Dhayalan B, Chen YS, Chatterjee D, Varas N, Weiss MA. Structural principles of insulin formulation and analog design: A century of innovation. Mol Metab 2021; 52:101325. [PMID: 34428558 PMCID: PMC8513154 DOI: 10.1016/j.molmet.2021.101325] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The discovery of insulin in 1921 and its near-immediate clinical use initiated a century of innovation. Advances extended across a broad front, from the stabilization of animal insulin formulations to the frontiers of synthetic peptide chemistry, and in turn, from the advent of recombinant DNA manufacturing to structure-based protein analog design. In each case, a creative interplay was observed between pharmaceutical applications and then-emerging principles of protein science; indeed, translational objectives contributed to a growing molecular understanding of protein structure, aggregation and misfolding. SCOPE OF REVIEW Pioneering crystallographic analyses-beginning with Hodgkin's solving of the 2-Zn insulin hexamer-elucidated general features of protein self-assembly, including zinc coordination and the allosteric transmission of conformational change. Crystallization of insulin was exploited both as a step in manufacturing and as a means of obtaining protracted action. Forty years ago, the confluence of recombinant human insulin with techniques for site-directed mutagenesis initiated the present era of insulin analogs. Variant or modified insulins were developed that exhibit improved prandial or basal pharmacokinetic (PK) properties. Encouraged by clinical trials demonstrating the long-term importance of glycemic control, regimens based on such analogs sought to resemble daily patterns of endogenous β-cell secretion more closely, ideally with reduced risk of hypoglycemia. MAJOR CONCLUSIONS Next-generation insulin analog design seeks to explore new frontiers, including glucose-responsive insulins, organ-selective analogs and biased agonists tailored to address yet-unmet clinical needs. In the coming decade, we envision ever more powerful scientific synergies at the interface of structural biology, molecular physiology and therapeutics.
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Affiliation(s)
- Mark A Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA
| | - Nicolás Varas
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, 46202, IN, USA; Department of Chemistry, Indiana University, Bloomington, 47405, IN, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, 47907, IN, USA.
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8
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Abstract
Insight into folding mechanisms of proinsulin has been provided by analysis of dominant diabetes-associated mutations in the human insulin gene (INS). Such mutations cause pancreatic β-cell dysfunction due to toxic misfolding of a mutant proinsulin and impairment in trans of wild-type insulin secretion. Anticipated by the "Akita" mouse (a classical model of monogenic diabetes mellitus; DM), this syndrome illustrates the paradigm endoreticulum (ER) stress leading to intracellular proteotoxicity. Diverse clinical mutations directly or indirectly perturb native disulfide pairing leading to protein misfolding and aberrant aggregation. Although most introduce or remove a cysteine (Cys; leading in either case to an unpaired thiol group), non-Cys-related mutations identify key determinants of folding efficiency. Studies of such mutations suggest that the hormone's evolution has been constrained not only by structure-function relationships, but also by the susceptibility of its single-chain precursor to impaired foldability. An intriguing hypothesis posits that INS overexpression in response to peripheral insulin resistance likewise leads to chronic ER stress and β-cell dysfunction in the natural history of non-syndromic Type 2 DM. Cryptic contributions of conserved residues to folding efficiency, as uncovered by rare genetic variants, define molecular links between biophysical principles and the emerging paradigm of Darwinian medicine: Biosynthesis of proinsulin at the edge of non-foldability provides a key determinant of "diabesity" as a pandemic disease of civilization.
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Affiliation(s)
| | | | | | - Michael A. Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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;
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Haataja L, Arunagiri A, Hassan A, Regan K, Tsai B, Dhayalan B, Weiss MA, Liu M, Arvan P. Distinct states of proinsulin misfolding in MIDY. Cell Mol Life Sci 2021; 78:6017-6031. [PMID: 34245311 PMCID: PMC8316239 DOI: 10.1007/s00018-021-03871-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/17/2021] [Accepted: 06/01/2021] [Indexed: 12/11/2022]
Abstract
A precondition for efficient proinsulin export from the endoplasmic reticulum (ER) is that proinsulin meets ER quality control folding requirements, including formation of the Cys(B19)–Cys(A20) “interchain” disulfide bond, facilitating formation of the Cys(B7)–Cys(A7) bridge. The third proinsulin disulfide, Cys(A6)–Cys(A11), is not required for anterograde trafficking, i.e., a “lose-A6/A11” mutant [Cys(A6), Cys(A11) both converted to Ser] is well secreted. Nevertheless, an unpaired Cys(A11) can participate in disulfide mispairings, causing ER retention of proinsulin. Among the many missense mutations causing the syndrome of Mutant INS gene-induced Diabetes of Youth (MIDY), all seem to exhibit perturbed proinsulin disulfide bond formation. Here, we have examined a series of seven MIDY mutants [including G(B8)V, Y(B26)C, L(A16)P, H(B5)D, V(B18)A, R(Cpep + 2)C, E(A4)K], six of which are essentially completely blocked in export from the ER in pancreatic β-cells. Three of these mutants, however, must disrupt the Cys(A6)–Cys(A11) pairing to expose a critical unpaired cysteine thiol perturbation of proinsulin folding and ER export, because when introduced into the proinsulin lose-A6/A11 background, these mutants exhibit native-like disulfide bonding and improved trafficking. This maneuver also ameliorates dominant-negative blockade of export of co-expressed wild-type proinsulin. A growing molecular understanding of proinsulin misfolding may permit allele-specific pharmacological targeting for some MIDY mutants.
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Affiliation(s)
- Leena Haataja
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA
| | - Anoop Arunagiri
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA
| | - Anis Hassan
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA
| | - Kaitlin Regan
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, 46202, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, 46202, USA
| | - Ming Liu
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA.,Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Peter Arvan
- The Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, MI, 48105, USA.
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Chen YS, Gleaton J, Yang Y, Dhayalan B, Phillips NB, Liu Y, Broadwater L, Jarosinski M, Chatterjee D, Lawrence MC, Hattier T, Michael DM, Weiss MA. Insertion of a Synthetic Switch Into Insulin Provides Metabolite-Dependent Regulation of Hormone-Receptor Activation. J Endocr Soc 2021. [PMCID: PMC8090162 DOI: 10.1210/jendso/bvab048.899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Insulin signaling requires conformational change: whereas the free hormone and its receptor each adopt autoinhibited conformations, their binding leads to large-scale structural reorganization. To test the coupling between insulin’s “opening” and receptor activation, we inserted an artificial ligand-dependent switch into insulin. 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 receptor. Similarly, metabolite-regulated signaling was not observed in control studies of (i) an unmodified insulin analog or (ii) an analog containing a diol sensor in the absence of internal tethering. Although as expected CD-detected secondary structure 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 holoreceptor signaling. In addition to this basic finding, our results provide proof of principle for 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 designed to mitigate risk of hypoglycemia in the treatment of diabetes mellitus.
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Affiliation(s)
- Yen-Shan Chen
- Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Yanwu Yang
- Indiana University School of Medicine, Indianapolis, IN, USA
| | | | | | - Yule Liu
- Thermalin, Inc, Cleveland, OH, USA
| | | | - Mark Jarosinski
- Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Michael C Lawrence
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
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12
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.
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13
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Dhayalan B, Chatterjee D, Chen YS, Weiss MA. Diabetes mellitus due to toxic misfolding of proinsulin variants. Mol Metab 2021:101229. [PMID: 33823319 DOI: 10.1016/j.molmet.2021.101229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/10/2021] [Accepted: 03/29/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Dominant mutations in the human insulin gene (INS) lead to pancreatic β-cell dysfunction and diabetes mellitus (DM) due to toxic misfolding of a mutant proinsulin. Analogous to a classical mouse model of monogenic DM ("Akita"), this syndrome highlights the susceptibility of β-cells to endoreticulum (ER) stress due to protein misfolding and aberrant aggregation. SCOPE OF REVIEW Diverse clinical mutations directly or indirectly perturb native disulfide pairing. Whereas most introduce or remove a cysteine (Cys; leading in either case to an unpaired thiol group), non-Cys-related mutations identify key determinants of folding efficiency. Studies of such mutations suggest that the hormone's evolution has been constrained not only by structure-function relationships but also by the susceptibility of its single-chain precursor to impaired foldability. An intriguing hypothesis posits that INS overexpression in response to peripheral insulin resistance likewise leads to chronic ER stress and β-cell dysfunction in the natural history of nonsyndromic Type 2 DM. MAJOR CONCLUSIONS Cryptic contributions of conserved residues to folding efficiency, as uncovered by rare genetic variants, define molecular links between biophysical principles and the emerging paradigm of Darwinian medicine: Biosynthesis of proinsulin at the edge of nonfoldability provides a key determinant of "diabesity" as a pandemic disease of civilization.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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14
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Rege NK, Liu M, Yang Y, Dhayalan B, Wickramasinghe NP, Chen YS, Rahimi L, Guo H, Haataja L, Sun J, Ismail-Beigi F, Phillips NB, Arvan P, Weiss MA. Evolution of insulin at the edge of foldability and its medical implications. Proc Natl Acad Sci U S A 2020; 117:29618-29628. [PMID: 33154160 PMCID: PMC7703552 DOI: 10.1073/pnas.2010908117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Proteins have evolved to be foldable, and yet determinants of foldability may be inapparent once the native state is reached. Insight has emerged from studies of diseases of protein misfolding, exemplified by monogenic diabetes mellitus due to mutations in proinsulin leading to endoplasmic reticulum stress and β-cell death. Cellular foldability of human proinsulin requires an invariant Phe within a conserved crevice at the receptor-binding surface (position B24). Any substitution, even related aromatic residue TyrB24, impairs insulin biosynthesis and secretion. As a seeming paradox, a monomeric TyrB24 insulin analog exhibits a native-like structure in solution with only a modest decrement in stability. Packing of TyrB24 is similar to that of PheB24, adjoining core cystine B19-A20 to seal the core; the analog also exhibits native self-assembly. Although affinity for the insulin receptor is decreased ∼20-fold, biological activities in cells and rats were within the range of natural variation. Together, our findings suggest that the invariance of PheB24 among vertebrate insulins and insulin-like growth factors reflects an essential role in enabling efficient protein folding, trafficking, and secretion, a function that is inapparent in native structures. In particular, we envision that the para-hydroxyl group of TyrB24 hinders pairing of cystine B19-A20 in an obligatory on-pathway folding intermediate. The absence of genetic variation at B24 and other conserved sites near this disulfide bridge-excluded due to β-cell dysfunction-suggests that insulin has evolved to the edge of foldability. Nonrobustness of a protein's fitness landscape underlies both a rare monogenic syndrome and "diabesity" as a pandemic disease of civilization.
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Affiliation(s)
- Nischay K Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, 300052 Tianjin, China
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Yanwu Yang
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Balamurugan Dhayalan
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | | | - Yen-Shan Chen
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Leili Rahimi
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106
| | - Huan Guo
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Jinhong Sun
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Faramarz Ismail-Beigi
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106
| | - Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106;
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106
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15
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Sun J, Xiong Y, Li X, Haataja L, Chen W, Mir SA, Lv L, Madley R, Larkin D, Anjum A, Dhayalan B, Rege N, Wickramasinghe NP, Weiss MA, Itkin-Ansari P, Kaufman RJ, Ostrov DA, Arvan P, Liu M. Role of Proinsulin Self-Association in Mutant INS Gene-Induced Diabetes of Youth. Diabetes 2020; 69:954-964. [PMID: 32139596 PMCID: PMC7171958 DOI: 10.2337/db19-1106] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/22/2020] [Indexed: 02/06/2023]
Abstract
Abnormal interactions between misfolded mutant and wild-type (WT) proinsulin (PI) in the endoplasmic reticulum (ER) drive the molecular pathogenesis of mutant INS gene-induced diabetes of youth (MIDY). How these abnormal interactions are initiated remains unknown. Normally, PI-WT dimerizes in the ER. Here, we suggest that the normal PI-PI contact surface, involving the B-chain, contributes to dominant-negative effects of misfolded MIDY mutants. Specifically, we find that PI B-chain tyrosine-16 (Tyr-B16), which is a key residue in normal PI dimerization, helps confer dominant-negative behavior of MIDY mutant PI-C(A7)Y. Substitutions of Tyr-B16 with either Ala, Asp, or Pro in PI-C(A7)Y decrease the abnormal interactions between the MIDY mutant and PI-WT, rescuing PI-WT export, limiting ER stress, and increasing insulin production in β-cells and human islets. This study reveals the first evidence indicating that noncovalent PI-PI contact initiates dominant-negative behavior of misfolded PI, pointing to a novel therapeutic target to enhance PI-WT export and increase insulin production.
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Affiliation(s)
- Jinhong Sun
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Yi Xiong
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Wei Chen
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
- Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Saiful A Mir
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - Li Lv
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Rachel Madley
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Dennis Larkin
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Arfah Anjum
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Nischay Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH
| | | | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Pamela Itkin-Ansari
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA
| | - David A Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Ming Liu
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
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16
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Dhayalan B, Chen YS, Phillips NB, Swain M, Rege NK, Mirsalehi A, Jarosinski M, Ismail-Beigi F, Metanis N, Weiss MA. Reassessment of an Innovative Insulin Analogue Excludes Protracted Action yet Highlights the Distinction between External and Internal Diselenide Bridges. Chemistry 2020; 26:4695-4700. [PMID: 31958351 DOI: 10.1002/chem.202000309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 01/31/2023]
Abstract
Long-acting insulin analogues represent the most prescribed class of therapeutic proteins. An innovative design strategy was recently proposed: diselenide substitution of an external disulfide bridge. This approach exploited the distinctive physicochemical properties of selenocysteine (U). Relative to wild type (WT), Se-insulin[C7UA , C7UB ] was reported to be protected from proteolysis by insulin-degrading enzyme (IDE), predicting prolonged activity. Because of this strategy's novelty and potential clinical importance, we sought to validate these findings and test their therapeutic utility in an animal model of diabetes mellitus. Surprisingly, the analogue did not exhibit enhanced stability, and its susceptibility to cleavage by either IDE or a canonical serine protease (glutamyl endopeptidase Glu-C) was similar to WT. Moreover, the analogue's pharmacodynamic profile in rats was not prolonged relative to a rapid-acting clinical analogue (insulin lispro). Although [C7UA , C7UB ] does not confer protracted action, nonetheless its comparison to internal diselenide bridges promises to provide broad biophysical insight.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yen-Shan Chen
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Mamuni Swain
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Nischay K Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Ali Mirsalehi
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Mark Jarosinski
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Faramarz Ismail-Beigi
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Norman Metanis
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra, Givat Ram, Jerusalem, 91904, Israel
| | - Michael A Weiss
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
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17
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Rege NK, Liu M, Dhayalan B, Chen YS, Smith NA, Rahimi L, Sun J, Guo H, Yang Y, Haataja L, Phillips NFB, Whittaker J, Smith BJ, Arvan P, Ismail-Beigi F, Weiss MA. "Register-shift" insulin analogs uncover constraints of proteotoxicity in protein evolution. J Biol Chem 2020; 295:3080-3098. [PMID: 32005662 DOI: 10.1074/jbc.ra119.011389] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/27/2020] [Indexed: 12/16/2022] Open
Abstract
Globular protein sequences encode not only functional structures (the native state) but also protein foldability, i.e. a conformational search that is both efficient and robustly minimizes misfolding. Studies of mutations associated with toxic misfolding have yielded insights into molecular determinants of protein foldability. Of particular interest are residues that are conserved yet dispensable in the native state. Here, we exploited the mutant proinsulin syndrome (a major cause of permanent neonatal-onset diabetes mellitus) to investigate whether toxic misfolding poses an evolutionary constraint. Our experiments focused on an invariant aromatic motif (PheB24-PheB25-TyrB26) with complementary roles in native self-assembly and receptor binding. A novel class of mutations provided evidence that insulin can bind to the insulin receptor (IR) in two different modes, distinguished by a "register shift" in this motif, as visualized by molecular dynamics (MD) simulations. Register-shift variants are active but defective in cellular foldability and exquisitely susceptible to fibrillation in vitro Indeed, expression of the corresponding proinsulin variant induced endoplasmic reticulum stress, a general feature of the mutant proinsulin syndrome. Although not present among vertebrate insulin and insulin-like sequences, a prototypical variant ([GlyB24]insulin) was as potent as WT insulin in a rat model of diabetes. Although in MD simulations the shifted register of receptor engagement is compatible with the structure and allosteric reorganization of the IR-signaling complex, our results suggest that this binding mode is associated with toxic misfolding and so is disallowed in evolution. The implicit threat of proteotoxicity limits sequence variation among vertebrate insulins and insulin-like growth factors.
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Affiliation(s)
- Nischay K Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Ming Liu
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105, Australia; Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, Heping District, 300052 China
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Nicholas A Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Leili Rahimi
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Jinhong Sun
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105, Australia
| | - Huan Guo
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105, Australia
| | - Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105, Australia
| | - Nelson F B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Jonathan Whittaker
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Brian J Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105, Australia
| | - Faramarz Ismail-Beigi
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106; Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
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18
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Feng CJ, Dhayalan B, Tokmakoff A. Refinement of Peptide Conformational Ensembles by 2D IR Spectroscopy: Application to Ala‒Ala‒Ala. Biophys J 2019; 114:2820-2832. [PMID: 29925019 DOI: 10.1016/j.bpj.2018.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/27/2018] [Accepted: 05/02/2018] [Indexed: 10/28/2022] Open
Abstract
Characterizing ensembles of intrinsically disordered proteins is experimentally challenging because of the ill-conditioned nature of ensemble determination with limited data and the intrinsic fast dynamics of the conformational ensemble. Amide I two-dimensional infrared (2D IR) spectroscopy has picosecond time resolution to freeze structural ensembles as needed for probing disordered-protein ensembles and conformational dynamics. Also, developments in amide I computational spectroscopy now allow a quantitative and direct prediction of amide I spectra based on conformational distributions drawn from molecular dynamics simulations, providing a route to ensemble refinement against experimental spectra. We performed a Bayesian ensemble refinement method on Ala-Ala-Ala against isotope-edited Fourier-transform infrared spectroscopy and 2D IR spectroscopy and tested potential factors affecting the quality of ensemble refinements. We found that isotope-edited 2D IR spectroscopy provides a stringent constraint on Ala-Ala-Ala conformations and returns consistent conformational ensembles with the dominant ppII conformer across varying prior distributions from many molecular dynamics force fields and water models. The dominant factor influencing ensemble refinements is the systematic frequency uncertainty from spectroscopic maps. However, the uncertainty of conformer populations can be significantly reduced by incorporating 2D IR spectra in addition to traditional Fourier-transform infrared spectra. Bayesian ensemble refinement against isotope-edited 2D IR spectroscopy thus provides a route to probe equilibrium-complex protein ensembles and potentially nonequilibrium conformational dynamics.
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Affiliation(s)
- Chi-Jui Feng
- Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois
| | - Balamurugan Dhayalan
- Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois.
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19
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Dhayalan B, Mandal K, Rege N, Weiss MA, Eitel SH, Meier T, Schoenleber RO, Kent SBH. Scope and Limitations of Fmoc Chemistry SPPS-Based Approaches to the Total Synthesis of Insulin Lispro via Ester Insulin. Chemistry 2017; 23:1709-1716. [PMID: 27905149 DOI: 10.1002/chem.201605578] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Indexed: 12/11/2022]
Abstract
We have systematically explored three approaches based on 9-fluorenylmethoxycarbonyl (Fmoc) chemistry solid phase peptide synthesis (SPPS) for the total chemical synthesis of the key depsipeptide intermediate for the efficient total chemical synthesis of insulin. The approaches used were: stepwise Fmoc chemistry SPPS; the "hybrid method", in which maximally protected peptide segments made by Fmoc chemistry SPPS are condensed in solution; and, native chemical ligation using peptide-thioester segments generated by Fmoc chemistry SPPS. A key building block in all three approaches was a Glu[O-β-(Thr)] ester-linked dipeptide equipped with a set of orthogonal protecting groups compatible with Fmoc chemistry SPPS. The most effective method for the preparation of the 51 residue ester-linked polypeptide chain of ester insulin was the use of unprotected peptide-thioester segments, prepared from peptide-hydrazides synthesized by Fmoc chemistry SPPS, and condensed by native chemical ligation. High-resolution X-ray crystallography confirmed the disulfide pairings and three-dimensional structure of synthetic insulin lispro prepared from ester insulin lispro by this route. Further optimization of these pilot studies could yield an efficient total chemical synthesis of insulin lispro (Humalog) based on peptide synthesis by Fmoc chemistry SPPS.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
| | - Kalyaneswar Mandal
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
| | - Nischay Rege
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Simon H Eitel
- Bachem AG, Hauptstrasse 144, 4416, Bubendorf, Switzerland
| | - Thomas Meier
- Bachem AG, Hauptstrasse 144, 4416, Bubendorf, Switzerland
| | | | - Stephen B H Kent
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
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20
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Dhayalan B, Fitzpatrick A, Mandal K, Whittaker J, Weiss MA, Tokmakoff A, Kent SBH. Efficient Total Chemical Synthesis of (13) C=(18) O Isotopomers of Human Insulin for Isotope-Edited FTIR. Chembiochem 2016; 17:415-20. [PMID: 26715336 DOI: 10.1002/cbic.201500601] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Indexed: 11/08/2022]
Abstract
Isotope-edited two-dimensional Fourier transform infrared spectroscopy (2 D FTIR) can potentially provide a unique probe of protein structure and dynamics. However, general methods for the site-specific incorporation of stable (13) C=(18) O labels into the polypeptide backbone of the protein molecule have not yet been established. Here we describe, as a prototype for the incorporation of specific arrays of isotope labels, the total chemical synthesis-via a key ester insulin intermediate-of 97 % enriched [(1-(13) C=(18) O)Phe(B24) ] human insulin: stable-isotope labeled at a single backbone amide carbonyl. The amino acid sequence as well as the positions of the disulfide bonds and the correctly folded structure were unambiguously confirmed by the X-ray crystal structure of the synthetic protein molecule. In vitro assays of the isotope labeled [(1-(13) C=(18) O)Phe(B24) ] human insulin showed that it had full insulin receptor binding activity. Linear and 2 D IR spectra revealed a distinct red-shifted amide I carbonyl band peak at 1595 cm(-1) resulting from the (1-(13) C=(18) O)Phe(B24) backbone label. This work illustrates the utility of chemical synthesis to enable the application of advanced physical methods for the elucidation of the molecular basis of protein function.
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Affiliation(s)
- Balamurugan Dhayalan
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Ann Fitzpatrick
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA.,The James Frank Institute, University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Kalyaneswar Mandal
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Jonathan Whittaker
- Department of Biochemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Michael A Weiss
- Department of Biochemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Andrei Tokmakoff
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA. .,The James Frank Institute, University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA.
| | - Stephen B H Kent
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA.
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21
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Mandal K, Dhayalan B, Avital-Shmilovici M, Tokmakoff A, Kent SBH. Crystallization of Enantiomerically Pure Proteins from Quasi-Racemic Mixtures: Structure Determination by X-Ray Diffraction of Isotope-Labeled Ester Insulin and Human Insulin. Chembiochem 2016; 17:421-5. [DOI: 10.1002/cbic.201500600] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Kalyaneswar Mandal
- Department of Chemistry; University of Chicago; 929 East 57th Street Chicago IL 60637 USA
| | - Balamurugan Dhayalan
- Department of Chemistry; University of Chicago; 929 East 57th Street Chicago IL 60637 USA
| | | | - Andrei Tokmakoff
- Department of Chemistry; University of Chicago; 929 East 57th Street Chicago IL 60637 USA
| | - Stephen B. H. Kent
- Department of Chemistry; University of Chicago; 929 East 57th Street Chicago IL 60637 USA
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22
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Gates ZP, Dhayalan B, Kent SBH. Obviation of hydrogen fluoride in Boc chemistry solid phase peptide synthesis of peptide-αthioesters. Chem Commun (Camb) 2016; 52:13979-13982. [DOI: 10.1039/c6cc07891e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Trifluoromethanesulfonic acid performs comparably to hydrogen fluoride for the on-resin global deprotection of peptides prepared by Boc chemistry solid phase peptide synthesis.
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23
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Dang B, Dhayalan B, Kent SBH. Enhanced Solvation of Peptides Attached to "Solid-Phase" Resins: Straightforward Syntheses of the Elastin Sequence Pro-Gly-Val-Gly-Val-Pro-Gly-Val-Gly-Val. Org Lett 2015; 17:3521-3. [PMID: 26110966 DOI: 10.1021/acs.orglett.5b01632] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The solubility-enhancing power of covalent attachment to solvent-swollen cross-linked resin supports was illustrated by syntheses of the highly aggregating elastin-derived 10-residue peptide sequence Pro-Gly-Val-Gly-Val-Pro-Gly-Val-Gly-Val using standard protocols for both Boc and Fmoc chemistry SPPS.
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Affiliation(s)
- Bobo Dang
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Balamurugan Dhayalan
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Stephen B H Kent
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
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