1
|
Marciano Y, Nayeem N, Dave D, Ulijn RV, Contel M. N-Acetylation of Biodegradable Supramolecular Peptide Nanofilaments Selectively Enhances Their Proteolytic Stability for Targeted Delivery of Gold-Based Anticancer Agents. ACS Biomater Sci Eng 2023; 9:3379-3389. [PMID: 37192486 PMCID: PMC10699682 DOI: 10.1021/acsbiomaterials.3c00312] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Peptide materials are promising for various biomedical applications; however, a significant concern is their lack of stability and rapid degradation in vivo due to non-specific proteolysis. For materials specifically designed to respond to disease-specific proteases, it would be desirable to retain high susceptibility to target proteases while minimizing the impact of non-specific proteolysis. We describe N-terminal acetylation as a simple synthetic modification of amphiphilic self-assembling peptides that contain an MMP-9-cleavable segment and form soluble, nanoscale filaments. We found that the N-terminus capping of these peptides did not significantly impact their self-assembly behavior, critical aggregation concentration, or ability to encapsulate hydrophobic payloads. By contrast, their proteolytic stability in human plasma (especially for anionic peptide sequences) was considerably increased while susceptibility to hydrolysis by MMP-9 was retained when compared to non-acetylated peptides, especially during the first 12 h. We note, however, that due to the longer time scale required for in vitro studies (72 h), non-specific proteolysis of both anionic acetylated peptides leads to similar activity in vitro despite differing MMP-9 kinetics during the early stages. Overall, the enhanced stability against non-specific proteases, combined with the ability of these nanofilaments to enhance the effectiveness of gold-based drugs toward cancerous cells compared to healthy cells, brings these acetylated peptide filaments a step closer toward clinical translation.
Collapse
Affiliation(s)
- Yaron Marciano
- Department of Chemistry, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- Advanced Science Research Center at The Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Nazia Nayeem
- Department of Chemistry, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- PhD Program Biology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Dhwanit Dave
- Advanced Science Research Center at The Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Rein V. Ulijn
- Advanced Science Research Center at The Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Maria Contel
- Department of Chemistry, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- PhD Program Biology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| |
Collapse
|
2
|
Jiráček J, Selicharová I, Žáková L. Mutations at hypothetical binding site 2 in insulin and insulin-like growth factors 1 and 2. VITAMINS AND HORMONES 2023; 123:187-230. [PMID: 37717985 DOI: 10.1016/bs.vh.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Elucidating how insulin and the related insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) bind to their cellular receptors (IR and IGF-1R) and how the receptors are activated has been the holy grail for generations of scientists. However, deciphering the 3D structure of tyrosine kinase receptors and their hormone-bound complexes has been complicated by the flexible and dimeric nature of the receptors and the dynamic nature of their interaction with hormones. Therefore, mutagenesis of hormones and kinetic studies first became an important tool for studying receptor interactions. It was suggested that hormones could bind to receptors through two binding sites on the hormone surface called site 1 and site 2. A breakthrough in knowledge came with the solution of cryoelectron microscopy (cryoEM) structures of hormone-receptor complexes. In this chapter, we document in detail the mutagenesis of insulin, IGF-1, and IGF-2 with emphasis on modifications of the hypothetical binding site 2 in the hormones, and we discuss the results of structure-activity studies in light of recent cryoEM structures of hormone complexes with IR and IGF-1R.
Collapse
Affiliation(s)
- Jiří Jiráček
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic.
| | - Irena Selicharová
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| | - Lenka Žáková
- From Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague, Czech Republic
| |
Collapse
|
3
|
Aggarwal S, Tanwar N, Singh A, Munde M. Formation of Protamine and Zn-Insulin Assembly: Exploring Biophysical Consequences. ACS OMEGA 2022; 7:41044-41057. [PMID: 36406544 PMCID: PMC9670714 DOI: 10.1021/acsomega.2c04419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The insulin-protamine interaction is at the core of the mode of action in many insulin formulations (Zn + insulin + protamine) and to treat diabetes, in which protamine is added to the stable form of hexameric insulin (Zn-insulin). However, due to the unavailability of quantitative data and a high-resolution structure, the binding mechanism of the insulin-protamine complex remains unknown. In this study, it was observed that Zn-insulin experiences destabilization as observed by the loss of secondary structure in circular dichroism (CD), and reduction in thermal stability in melting study, upon protamine binding. In isothermal titration calorimetry (ITC), it was found that the interactions were mostly enthalpically driven. This is in line with the positive ΔC m value (+880 cal mol-1), indicating the role of hydrophilic interactions in the complex formation, with the exposure of hydrophobic residues to the solvent, which was firmly supported by the 8-anilino-1-naphthalene sulfonate (ANS) binding study. The stoichiometry (N) value in ITC suggests the multiple insulin molecules binding to the protamine chain, which is consistent with the picture of the condensation of insulin in the presence of protamine. Atomic force microscopy (AFM) suggested the formation of a heterogeneous Zn-insulin-protamine complex. In fluorescence, Zn-insulin experiences strong Tyr quenching, suggesting that the location of the protamine-binding site is near Tyr, which is also supported by the molecular docking study. Since Tyr is critical in the stabilization of insulin self-assembly, its interaction with protamine may impair insulin's self-association ability and thermodynamic stability while at the same time promoting its flexible conformation desired for better biological activity.
Collapse
|
4
|
Hsu WT, Ramirez DA, Sammakia T, Tan Z, Shirts MR. Identifying signatures of proteolytic stability and monomeric propensity in O-glycosylated insulin using molecular simulation. J Comput Aided Mol Des 2022; 36:313-328. [PMID: 35507105 DOI: 10.1007/s10822-022-00453-6] [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: 10/29/2021] [Accepted: 04/06/2022] [Indexed: 11/24/2022]
Abstract
Insulin has been commonly adopted as a peptide drug to treat diabetes as it facilitates the uptake of glucose from the blood. The development of oral insulin remains elusive over decades owing to its susceptibility to the enzymes in the gastrointestinal tract and poor permeability through the intestinal epithelium upon dimerization. Recent experimental studies have revealed that certain O-linked glycosylation patterns could enhance insulin's proteolytic stability and reduce its dimerization propensity, but understanding such phenomena at the molecular level is still difficult. To address this challenge, we proposed and tested several structural determinants that could potentially influence insulin's proteolytic stability and dimerization propensity. We used these metrics to assess the properties of interest from [Formula: see text] aggregate molecular dynamics of each of 12 targeted insulin glyco-variants from multiple wild-type crystal structures. We found that glycan-involved hydrogen bonds and glycan-dimer occlusion were useful metrics predicting the proteolytic stability and dimerization propensity of insulin, respectively, as was in part the solvent-accessible surface area of proteolytic sites. However, other plausible metrics were not generally predictive. This work helps better explain how O-linked glycosylation influences the proteolytic stability and monomeric propensity of insulin, illuminating a path towards rational molecular design of insulin glycoforms.
Collapse
Affiliation(s)
- Wei-Tse Hsu
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Dominique A Ramirez
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Tarek Sammakia
- Department of Chemistry, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Zhongping Tan
- Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100050, China.
| | - Michael R Shirts
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA.
| |
Collapse
|
5
|
Páníková T, Mitrová K, Halamová T, Mrzílková K, Pícha J, Chrudinová M, Kurochka A, Selicharová I, Žáková L, Jiráček J. Insulin Analogues with Altered Insulin Receptor Isoform Binding Specificities and Enhanced Aggregation Stabilities. J Med Chem 2021; 64:14848-14859. [PMID: 34591477 DOI: 10.1021/acs.jmedchem.1c01388] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Insulin is a lifesaver for millions of diabetic patients. There is a need for new insulin analogues with more physiological profiles and analogues that will be thermally more stable than human insulin. Here, we describe the chemical engineering of 48 insulin analogues that were designed to have changed binding specificities toward isoforms A and B of the insulin receptor (IR-A and IR-B). We systematically modified insulin at the C-terminus of the B-chain, at the N-terminus of the A-chain, and at A14 and A18 positions. We discovered an insulin analogue that has Cα-carboxyamidated Glu at B31 and Ala at B29 and that has a more than 3-fold-enhanced binding specificity in favor of the "metabolic" IR-B isoform. The analogue is more resistant to the formation of insulin fibrils at 37 °C and is also more efficient in mice than human insulin. Therefore, [AlaB29,GluB31,amideB31]-insulin may be interesting for further clinical evaluation.
Collapse
Affiliation(s)
- Terezie Páníková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Katarína Mitrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Tereza Halamová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Karolína Mrzílková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Jan Pícha
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Andrii Kurochka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 116 10 Prague 6, Czech Republic
| |
Collapse
|
6
|
Zhang AM, Wellberg EA, Kopp JL, Johnson JD. Hyperinsulinemia in Obesity, Inflammation, and Cancer. Diabetes Metab J 2021; 45:285-311. [PMID: 33775061 PMCID: PMC8164941 DOI: 10.4093/dmj.2020.0250] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
The relative insufficiency of insulin secretion and/or insulin action causes diabetes. However, obesity and type 2 diabetes mellitus can be associated with an absolute increase in circulating insulin, a state known as hyperinsulinemia. Studies are beginning to elucidate the cause-effect relationships between hyperinsulinemia and numerous consequences of metabolic dysfunctions. Here, we review recent evidence demonstrating that hyperinsulinemia may play a role in inflammation, aging and development of cancers. In this review, we will focus on the consequences and mechanisms of excess insulin production and action, placing recent findings that have challenged dogma in the context of the existing body of literature. Where relevant, we elaborate on the role of specific signal transduction components in the actions of insulin and consequences of chronic hyperinsulinemia. By discussing the involvement of hyperinsulinemia in various metabolic and other chronic diseases, we may identify more effective therapeutics or lifestyle interventions for preventing or treating obesity, diabetes and cancer. We also seek to identify pertinent questions that are ripe for future investigation.
Collapse
Affiliation(s)
- Anni M.Y. Zhang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth A. Wellberg
- Department of Pathology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Center, Oklahoma City, OK, USA
| | - Janel L. Kopp
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Corresponding author: James D. Johnson https://orcid.org/0000-0002-7523-9433 Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2329 W Mall Vancouver, BC V6T 1Z4, Vancouver, BC, Canada E-mail:
| |
Collapse
|
7
|
Dzianová P, Asai S, Chrudinová M, Kosinová L, Potalitsyn P, Šácha P, Hadravová R, Selicharová I, Kříž J, Turkenburg JP, Brzozowski AM, Jiráček J, Žáková L. The efficiency of insulin production and its content in insulin-expressing model β-cells correlate with their Zn 2+ levels. Open Biol 2020; 10:200137. [PMID: 33081637 PMCID: PMC7653362 DOI: 10.1098/rsob.200137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/24/2020] [Indexed: 12/29/2022] Open
Abstract
Insulin is produced and stored inside the pancreatic β-cell secretory granules, where it is assumed to form Zn2+-stabilized oligomers. However, the actual storage forms of this hormone and the impact of zinc ions on insulin production in vivo are not known. Our initial X-ray fluorescence experiment on granules from native Langerhans islets and insulinoma-derived INS-1E cells revealed a considerable difference in the zinc content. This led our further investigation to evaluate the impact of the intra-granular Zn2+ levels on the production and storage of insulin in different model β-cells. Here, we systematically compared zinc and insulin contents in the permanent INS-1E and BRIN-BD11 β-cells and in the native rat pancreatic islets by flow cytometry, confocal microscopy, immunoblotting, specific messenger RNA (mRNA) and total insulin analysis. These studies revealed an impaired insulin production in the permanent β-cell lines with the diminished intracellular zinc content. The drop in insulin and Zn2+ levels was paralleled by a lower expression of ZnT8 zinc transporter mRNA and hampered proinsulin processing/folding in both permanent cell lines. To summarize, we showed that the disruption of zinc homeostasis in the model β-cells correlated with their impaired insulin and ZnT8 production. This indicates a need for in-depth fundamental research about the role of zinc in insulin production and storage.
Collapse
Affiliation(s)
- Petra Dzianová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Seiya Asai
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Lucie Kosinová
- Laboratory of Pancreatic Islets, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech Republic
| | - Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague 2, Czech Republic
| | - Pavel Šácha
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Romana Hadravová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Jan Kříž
- Laboratory of Pancreatic Islets, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech Republic
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Andrzej Marek Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10 Prague 6, Czech Republic
| |
Collapse
|
8
|
Evans BJ, King AT, Katsifis A, Matesic L, Jamie JF. Methods to Enhance the Metabolic Stability of Peptide-Based PET Radiopharmaceuticals. Molecules 2020; 25:molecules25102314. [PMID: 32423178 PMCID: PMC7287708 DOI: 10.3390/molecules25102314] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/28/2022] Open
Abstract
The high affinity and specificity of peptides towards biological targets, in addition to their favorable pharmacological properties, has encouraged the development of many peptide-based pharmaceuticals, including peptide-based positron emission tomography (PET) radiopharmaceuticals. However, the poor in vivo stability of unmodified peptides against proteolysis is a major challenge that must be overcome, as it can result in an impractically short in vivo biological half-life and a subsequently poor bioavailability when used in imaging and therapeutic applications. Consequently, many biologically and pharmacologically interesting peptide-based drugs may never see application. A potential way to overcome this is using peptide analogues designed to mimic the pharmacophore of a native peptide while also containing unnatural modifications that act to maintain or improve the pharmacological properties. This review explores strategies that have been developed to increase the metabolic stability of peptide-based pharmaceuticals. It includes modifications of the C- and/or N-termini, introduction of d- or other unnatural amino acids, backbone modification, PEGylation and alkyl chain incorporation, cyclization and peptide bond substitution, and where those strategies have been, or could be, applied to PET peptide-based radiopharmaceuticals.
Collapse
Affiliation(s)
- Brendan J. Evans
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
| | - Andrew T. King
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia;
| | - Lidia Matesic
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia;
| | - Joanne F. Jamie
- Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia; (B.J.E.); (A.T.K.)
- Correspondence: ; Tel.: +61-2-9850-8283
| |
Collapse
|
9
|
Gong Q, Zhang H, Zhang H, Chen C. Calculating the absolute binding free energy of the insulin dimer in an explicit solvent. RSC Adv 2020; 10:790-800. [PMID: 35494470 PMCID: PMC9047981 DOI: 10.1039/c9ra08284k] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/23/2019] [Indexed: 12/23/2022] Open
Abstract
Insulin is a significant hormone in the regulation of glucose level in the blood. Its monomers bind to each other to form dimers or hexamers through a complex process. To study the binding of the insulin dimer, we first calculate its absolute binding free energy by the steered molecular dynamics method and the confinement method based on a fictitious thermodynamic cycle. After considering some special correction terms, the final calculated binding free energy at 298 K is −8.97 ± 1.41 kcal mol−1, which is close to the experimental value of −7.2 ± 0.8 kcal mol−1. Furthermore, we discuss the important residue–residue interactions between the insulin monomers, including hydrophobic interactions, π–π interactions and hydrogen bond interactions. The analysis reveals five key residues, VlaB12, TyrB16, PheB24, PheB25, and TyrB26, for the dimerization of the insulin. We also perform MM-PBSA calculations for the wild-type dimer and some mutants and study the roles of the key residues by the change of the binding energy of the insulin dimer. In this paper, we calculate the absolute binding free energy of an insulin dimer by steered MD method. The result of −8.97 kcal mol−1 is close to the experimental value −7.2 kcal mol−1. We also analyze the residue–residue interactions.![]()
Collapse
Affiliation(s)
- Qiankun Gong
- Biomolecular Physics and Modeling Group
- School of Physics
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Haomiao Zhang
- Biomolecular Physics and Modeling Group
- School of Physics
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Haozhe Zhang
- Biomolecular Physics and Modeling Group
- School of Physics
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Changjun Chen
- Biomolecular Physics and Modeling Group
- School of Physics
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| |
Collapse
|
10
|
Desmond JL, Koner D, Meuwly M. Probing the Differential Dynamics of the Monomeric and Dimeric Insulin from Amide-I IR Spectroscopy. J Phys Chem B 2019; 123:6588-6598. [PMID: 31318551 DOI: 10.1021/acs.jpcb.9b04628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The monomer-dimer equilibrium for insulin is one of the essential steps in forming the receptor-binding competent monomeric form of the hormone. Despite this importance, the thermodynamic stability, in particular for modified insulins, is quite poorly understood, in part, due to experimental difficulties. This work explores one- and two-dimensional infrared spectroscopy in the range of the amide-I band for the hydrated monomeric and dimeric wild-type hormone. It is found that for the monomer the frequency fluctuation correlation function (FFCF) and the one-dimensional infrared spectra are position sensitive. The spectra of the -CO probes at the dimerization interface (residues Phe24, Phe25, and Tyr26) split and indicate an asymmetry despite the overall (formal) point symmetry of the dimer structure. Also, the decay times of the FFCF for the same -CO probe in the monomer and the dimer can differ by up to 1 order of magnitude, for example, for residue PheB24, which is solvent exposed for the monomer but at the interface for the dimer. The spectroscopic shifts correlate approximately with the average number of hydration waters and the magnitude of the FFCF at time zero. However, this correlation is only qualitative due to the heterogeneous and highly dynamical environment. Based on density functional theory calculations, the dominant contribution for solvent-exposed -CO is found to arise from the surrounding water (∼75%), whereas the protein environment contributes considerably less. The results suggest that infrared spectroscopy is a positionally sensitive probe of insulin dimerization, in particular in conjunction with isotopic labeling of the probe.
Collapse
Affiliation(s)
- Jasmine L Desmond
- Department of Chemistry , University of Basel , Klingelbergstrasse 80 , 4056 Basel , Switzerland
| | - Debasish Koner
- Department of Chemistry , University of Basel , Klingelbergstrasse 80 , 4056 Basel , Switzerland
| | - Markus Meuwly
- Department of Chemistry , University of Basel , Klingelbergstrasse 80 , 4056 Basel , Switzerland
| |
Collapse
|
11
|
Banerjee P, Mondal S, Bagchi B. Effect of ethanol on insulin dimer dissociation. J Chem Phys 2019; 150:084902. [PMID: 30823756 DOI: 10.1063/1.5079501] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Insulin-dimer dissociation is an essential biochemical process required for the activity of the hormone. We investigate this dissociation process at the molecular level in water and at the same time, in 5% and 10% water-ethanol mixtures. We compute the free energy surface of the protein dissociation processes by employing biased molecular dynamics simulation. In the presence of ethanol (EtOH), we observe a marked lowering in the free energy barrier of activation of dimer dissociation from that in the neat water, by as much as ∼50%, even in the 5% water-ethanol solution. In addition, ethanol is found to induce significant changes in the dissociation pathway. We extract the most probable conformations of the intermediate states along the minimum energy pathway in the case of all the three concentrations (EtOH mole fractions 0, 5, and 10). We explore the change in microscopic structures that occur in the presence of ethanol. Interestingly, we discover a stable intermediate state in the water-ethanol binary mixture where the centers of the monomers are separated by about 3 nm and the contact order parameter is close to zero. This intermediate is stabilized by the wetting of the interface between the two monomers by the preferential distribution of ethanol and water molecules. This wetting serves to reduce the free energy barrier significantly and thus results in an increase in the rate of dimer dissociation. We also analyze the solvation of the two monomers during the dissociation and both the proteins' departure from the native state configuration to obtain valuable insights into the dimer dissociation processes.
Collapse
Affiliation(s)
- Puja Banerjee
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Sayantan Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
12
|
Chrudinová M, Žáková L, Marek A, Socha O, Buděšínský M, Hubálek M, Pícha J, Macháčková K, Jiráček J, Selicharová I. A versatile insulin analog with high potency for both insulin and insulin-like growth factor 1 receptors: Structural implications for receptor binding. J Biol Chem 2018; 293:16818-16829. [PMID: 30213860 PMCID: PMC6204900 DOI: 10.1074/jbc.ra118.004852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/05/2018] [Indexed: 12/02/2022] Open
Abstract
Insulin and insulin-like growth factor 1 (IGF-1) are closely related hormones involved in the regulation of metabolism and growth. They elicit their functions through activation of tyrosine kinase–type receptors: insulin receptors (IR-A and IR-B) and IGF-1 receptor (IGF-1R). Despite similarity in primary and three-dimensional structures, insulin and IGF-1 bind the noncognate receptor with substantially reduced affinity. We prepared [d-HisB24, GlyB31, TyrB32]-insulin, which binds all three receptors with high affinity (251 or 338% binding affinity to IR-A respectively to IR-B relative to insulin and 12.4% binding affinity to IGF-1R relative to IGF-1). We prepared other modified insulins with the aim of explaining the versatility of [d-HisB24, GlyB31, TyrB32]-insulin. Through structural, activity, and kinetic studies of these insulin analogs, we concluded that the ability of [d-HisB24, GlyB31, TyrB32]-insulin to stimulate all three receptors is provided by structural changes caused by a reversed chirality at the B24 combined with the extension of the C terminus of the B chain by two extra residues. We assume that the structural changes allow the directing of the B chain C terminus to some extra interactions with the receptors. These unusual interactions lead to a decrease of dissociation rate from the IR and conversely enable easier association with IGF-1R. All of the structural changes were made at the hormones' Site 1, which is thought to interact with the Site 1 of the receptors. The results of the study suggest that merely modifications of Site 1 of the hormone are sufficient to change the receptor specificity of insulin.
Collapse
Affiliation(s)
- Martina Chrudinová
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Lenka Žáková
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Aleš Marek
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Ondřej Socha
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Miloš Buděšínský
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Martin Hubálek
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Jan Pícha
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Kateřina Macháčková
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Jiří Jiráček
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Irena Selicharová
- From the Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| |
Collapse
|
13
|
Fabre B, Pícha J, Selicharová I, Žáková L, Chrudinová M, Hajduch J, Jiráček J. Probing Tripodal Peptide Scaffolds as Insulin and IGF-1 Receptor Ligands. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Benjamin Fabre
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jan Pícha
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jan Hajduch
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences, v.v.i.; Flemingovo n. 2, 16610 6 Praha Czech Republic
| |
Collapse
|
14
|
Akbarian M, Ghasemi Y, Uversky VN, Yousefi R. Chemical modifications of insulin: Finding a compromise between stability and pharmaceutical performance. Int J Pharm 2018; 547:450-468. [DOI: 10.1016/j.ijpharm.2018.06.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 02/07/2023]
|
15
|
Raghunathan S, El Hage K, Desmond JL, Zhang L, Meuwly M. The Role of Water in the Stability of Wild-type and Mutant Insulin Dimers. J Phys Chem B 2018; 122:7038-7048. [DOI: 10.1021/acs.jpcb.8b04448] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shampa Raghunathan
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Krystel El Hage
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Jasmine L. Desmond
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Lixian Zhang
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
16
|
Lieblich SA, Fang KY, Cahn JKB, Rawson J, LeBon J, Ku HT, Tirrell DA. 4S-Hydroxylation of Insulin at ProB28 Accelerates Hexamer Dissociation and Delays Fibrillation. J Am Chem Soc 2017; 139:8384-8387. [PMID: 28598606 PMCID: PMC5812673 DOI: 10.1021/jacs.7b00794] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Daily injections of insulin provide lifesaving benefits to millions of diabetics. But currently available prandial insulins are suboptimal: The onset of action is delayed by slow dissociation of the insulin hexamer in the subcutaneous space, and insulin forms amyloid fibrils upon storage in solution. Here we show, through the use of noncanonical amino acid mutagenesis, that replacement of the proline residue at position 28 of the insulin B-chain (ProB28) by (4S)-hydroxyproline (Hzp) yields an active form of insulin that dissociates more rapidly, and fibrillates more slowly, than the wild-type protein. Crystal structures of dimeric and hexameric insulin preparations suggest that a hydrogen bond between the hydroxyl group of Hzp and a backbone amide carbonyl positioned across the dimer interface may be responsible for the altered behavior. The effects of hydroxylation are stereospecific; replacement of ProB28 by (4R)-hydroxyproline (Hyp) causes little change in the rates of fibrillation and hexamer disassociation. These results demonstrate a new approach that fuses the concepts of medicinal chemistry and protein design, and paves the way to further engineering of insulin and other therapeutic proteins.
Collapse
Affiliation(s)
- Seth A. Lieblich
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Katharine Y. Fang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jackson K. B. Cahn
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jeffrey Rawson
- Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA 91010, USA
- Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Jeanne LeBon
- Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA 91010, USA
| | - H. Teresa Ku
- Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA 91010, USA
- Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
- Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA 91010, USA
| | - David A. Tirrell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
17
|
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] [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.
Collapse
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
| |
Collapse
|
18
|
Fabre B, Pícha J, Vaněk V, Selicharová I, Chrudinová M, Collinsová M, Žáková L, Buděšínský M, Jiráček J. Synthesis and Evaluation of a Library of Trifunctional Scaffold-Derived Compounds as Modulators of the Insulin Receptor. ACS COMBINATORIAL SCIENCE 2016; 18:710-722. [PMID: 27936668 DOI: 10.1021/acscombsci.6b00132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We designed a combinatorial library of trifunctional scaffold-derived compounds, which were derivatized with 30 different in-house-made azides. The compounds were proposed to mimic insulin receptor (IR)-binding epitopes in the insulin molecule and bind to and activate this receptor. This work has enabled us to test our synthetic and biological methodology and to prove its robustness and reliability for the solid-phase synthesis and testing of combinatorial libraries of the trifunctional scaffold-derived compounds. Our effort resulted in the discovery of two compounds, which were able to weakly induce the autophosphorylation of IR and weakly bind to this receptor at a 0.1 mM concentration. Despite these modest biological results, which well document the well-known difficulty in modulating protein-protein interactions, this study represents a unique example of targeting the IR with a set of nonpeptide compounds that were specifically designed and synthesized for this purpose. We believe that this work can open new perspectives for the development of next-generation insulin mimetics based on the scaffold structure.
Collapse
Affiliation(s)
- Benjamin Fabre
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Jan Pícha
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Václav Vaněk
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Michaela Collinsová
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Miloš Buděšínský
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry
and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha 6, Czech Republic
| |
Collapse
|
19
|
Zhang XX, Jones KC, Fitzpatrick A, Peng CS, Feng CJ, Baiz CR, Tokmakoff A. Studying Protein-Protein Binding through T-Jump Induced Dissociation: Transient 2D IR Spectroscopy of Insulin Dimer. J Phys Chem B 2016; 120:5134-45. [PMID: 27203447 DOI: 10.1021/acs.jpcb.6b03246] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Insulin homodimer associates through the coupled folding and binding of two partially disordered monomers. We aim to understand this dynamics by observing insulin dimer dissociation initiated with a nanosecond temperature jump using transient two-dimensional infrared spectroscopy (2D IR) of amide I vibrations. With the help of equilibrium FTIR and 2D IR spectra, and through a systematic study of the dependence of dissociation kinetics on temperature and insulin concentration, we are able to decompose and analyze the spectral evolution associated with different secondary structures. We find that the dissociation under all conditions is characterized by two processes whose influence on the kinetics varies with temperature: the unfolding of the β sheet at the dimer interface observed as exponential kinetics between 250 and 1000 μs and nonexponential kinetics between 5 and 150 μs that we attribute to monomer disordering. Microscopic reversibility arguments lead us to conclude that dimer association requires significant conformational changes within the monomer in concert with the folding of the interfacial β sheet. While our data indicates a more complex kinetics, we apply a two-state model to the β-sheet unfolding kinetics to extract thermodynamic parameters and kinetic rate constants. The association rate constant, ka (23 °C) = 8.8 × 10(5) M(-1) s(-1) (pH 0, 20% EtOD), is approximately 3 orders of magnitude slower than the calculated diffusion limited association rate, which is explained by the significant destabilizing effect of ethanol on the dimer state and the highly positive charge of the monomers at this pH.
Collapse
Affiliation(s)
- Xin-Xing Zhang
- Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Kevin C Jones
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Ann Fitzpatrick
- Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Chunte Sam Peng
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Chi-Jui Feng
- Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Carlos R Baiz
- Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Andrei Tokmakoff
- Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| |
Collapse
|
20
|
Křížková K, Chrudinová M, Povalová A, Selicharová I, Collinsová M, Vaněk V, Brzozowski AM, Jiráček J, Žáková L. Insulin–Insulin-like Growth Factors Hybrids as Molecular Probes of Hormone:Receptor Binding Specificity. Biochemistry 2016; 55:2903-13. [DOI: 10.1021/acs.biochem.6b00140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Květoslava Křížková
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
- Charles University in Prague, Faculty of Science,
Department of Biochemistry, Hlavova 8, 128 43 Praha 2, Czech Republic
| | - Martina Chrudinová
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
- Charles University in Prague, Faculty of Science,
Department of Biochemistry, Hlavova 8, 128 43 Praha 2, Czech Republic
| | - Anna Povalová
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
- Charles University in Prague, Faculty of Science,
Department of Biochemistry, Hlavova 8, 128 43 Praha 2, Czech Republic
| | - Irena Selicharová
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| | - Michaela Collinsová
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| | - Václav Vaněk
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| | - Andrzej M. Brzozowski
- York
Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Jiří Jiráček
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| | - Lenka Žáková
- Institute
of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic v.v.i., Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
| |
Collapse
|
21
|
Rawat S, Gupta P, Kumar A, Garg P, Suri CR, Sahoo DK. Molecular Mechanism of Poly(vinyl alcohol) Mediated Prevention of Aggregation and Stabilization of Insulin in Nanoparticles. Mol Pharm 2015; 12:1018-30. [DOI: 10.1021/mp5003653] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sanjay Rawat
- CSIR−Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Pawan Gupta
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector 67, Mohali 160062, India
| | - Anil Kumar
- CSIR−Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Prabha Garg
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Sector 67, Mohali 160062, India
| | - C. Raman Suri
- CSIR−Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Debendra K. Sahoo
- CSIR−Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| |
Collapse
|
22
|
Křížková K, Veverka V, Maletínská L, Hexnerová R, Brzozowski AM, Jiráček J, Žáková L. Structural and functional study of the GlnB22-insulin mutant responsible for maturity-onset diabetes of the young. PLoS One 2014; 9:e112883. [PMID: 25423173 PMCID: PMC4244080 DOI: 10.1371/journal.pone.0112883] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 10/21/2014] [Indexed: 12/04/2022] Open
Abstract
The insulin gene mutation c.137G>A (R46Q), which changes an arginine at the B22 position of the mature hormone to glutamine, causes the monogenic diabetes variant maturity-onset diabetes of the young (MODY). In MODY patients, this mutation is heterozygous, and both mutant and wild-type (WT) human insulin are produced simultaneously. However, the patients often depend on administration of exogenous insulin. In this study, we chemically synthesized the MODY mutant [GlnB22]-insulin and characterized its biological and structural properties. The chemical synthesis of this insulin analogue revealed that its folding ability is severely impaired. In vitro and in vivo tests showed that its binding affinity and biological activity are reduced (both approximately 20% that of human insulin). Comparison of the solution structure of [GlnB22]-insulin with the solution structure of native human insulin revealed that the most significant structural effect of the mutation is distortion of the B20-B23 β-turn, leading to liberation of the B chain C-terminus from the protein core. The distortion of the B20-B23 β-turn is caused by the extended conformational freedom of the GlnB22 side chain, which is no longer anchored in a hydrogen bonding network like the native ArgB22. The partially disordered [GlnB22]-insulin structure appears to be one reason for the reduced binding potency of this mutant and may also be responsible for its low folding efficiency in vivo. The altered orientation and flexibility of the B20-B23 β-turn may interfere with the formation of disulfide bonds in proinsulin bearing the R46Q (GlnB22) mutation. This may also have a negative effect on the WT proinsulin simultaneously biosynthesized in β-cells and therefore play a major role in the development of MODY in patients producing [GlnB22]-insulin.
Collapse
Affiliation(s)
- Květoslava Křížková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Lenka Maletínská
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Rozálie Hexnerová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York, YO10 5DD, United Kingdom
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
- * E-mail:
| |
Collapse
|
23
|
Žáková L, Kletvíková E, Lepšík M, Collinsová M, Watson CJ, Turkenburg JP, Jiráček J, Brzozowski AM. Human insulin analogues modified at the B26 site reveal a hormone conformation that is undetected in the receptor complex. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2765-74. [PMID: 25286859 PMCID: PMC4188015 DOI: 10.1107/s1399004714017775] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/01/2014] [Indexed: 11/10/2022]
Abstract
The structural characterization of the insulin-insulin receptor (IR) interaction still lacks the conformation of the crucial B21-B30 insulin region, which must be different from that in its storage forms to ensure effective receptor binding. Here, it is shown that insulin analogues modified by natural amino acids at the TyrB26 site can represent an active form of this hormone. In particular, [AsnB26]-insulin and [GlyB26]-insulin attain a B26-turn-like conformation that differs from that in all known structures of the native hormone. It also matches the receptor interface, avoiding substantial steric clashes. This indicates that insulin may attain a B26-turn-like conformation upon IR binding. Moreover, there is an unexpected, but significant, binding specificity of the AsnB26 mutant for predominantly the metabolic B isoform of the receptor. As it is correlated with the B26 bend of the B-chain of the hormone, the structures of AsnB26 analogues may provide the first structural insight into the structural origins of differential insulin signalling through insulin receptor A and B isoforms.
Collapse
Affiliation(s)
- Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Emília Kletvíková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Michaela Collinsová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Christopher J. Watson
- York Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York YO10 5DD, England
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York YO10 5DD, England
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, The University of York, Heslington, York YO10 5DD, England
| |
Collapse
|
24
|
Zabardasti A, Goudarziafshar H, Salehnassaj M, Oliveira BG. A computational study of hydrogen bonds in intermolecular systems of high complexity: arachno-pentaborane(11)···Y with Y = O2 and N2. J Mol Model 2014; 20:2403. [DOI: 10.1007/s00894-014-2403-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 07/28/2014] [Indexed: 11/29/2022]
|
25
|
Kosinová L, Veverka V, Novotná P, Collinsová M, Urbanová M, Moody NR, Turkenburg JP, Jiráček J, Brzozowski AM, Žáková L. Insight into the structural and biological relevance of the T/R transition of the N-terminus of the B-chain in human insulin. Biochemistry 2014; 53:3392-402. [PMID: 24819248 PMCID: PMC4047818 DOI: 10.1021/bi500073z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
![]()
The N-terminus of the B-chain of
insulin may adopt two alternative
conformations designated as the T- and R-states. Despite the recent
structural insight into insulin–insulin receptor (IR) complexes,
the physiological relevance of the T/R transition is still unclear.
Hence, this study focused on the rational design, synthesis, and characterization
of human insulin analogues structurally locked in expected R- or T-states.
Sites B3, B5, and B8, capable of affecting the conformation of the
N-terminus of the B-chain, were subjects of rational substitutions
with amino acids with specific allowed and disallowed dihedral φ
and ψ main-chain angles. α-Aminoisobutyric acid was systematically
incorporated into positions B3, B5, and B8 for stabilization of the
R-state, and N-methylalanine and d-proline
amino acids were introduced at position B8 for stabilization of the
T-state. IR affinities of the analogues were compared and correlated
with their T/R transition ability and analyzed against their crystal
and nuclear magnetic resonance structures. Our data revealed that
(i) the T-like state is indeed important for the folding efficiency
of (pro)insulin, (ii) the R-state is most probably incompatible with
an active form of insulin, (iii) the R-state cannot be induced or
stabilized by a single substitution at a specific site, and (iv) the
B1–B8 segment is capable of folding into a variety of low-affinity
T-like states. Therefore, we conclude that the active conformation
of the N-terminus of the B-chain must be different from the “classical”
T-state and that a substantial flexibility of the B1–B8 segment,
where GlyB8 plays a key role, is a crucial prerequisite for an efficient
insulin–IR interaction.
Collapse
Affiliation(s)
- Lucie Kosinová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Selivanova OM, Suvorina MY, Dovidchenko NV, Eliseeva IA, Surin AK, Finkelstein AV, Schmatchenko VV, Galzitskaya OV. How to determine the size of folding nuclei of protofibrils from the concentration dependence of the rate and lag-time of aggregation. II. Experimental application for insulin and LysPro insulin: aggregation morphology, kinetics, and sizes of nuclei. J Phys Chem B 2014; 118:1198-206. [PMID: 24428561 DOI: 10.1021/jp4083568] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Insulin is a commonly used protein for studies of amyloidogenesis. There are a few insulin analogues with different pharmacokinetic characteristics, in particular the onset and duration of action. One of them is LysPro insulin. The behavior of LysPro insulin in the process of amyloid formation has not been studied in detail yet. To quantitatively investigate the differences between insulin and LysPro insulin in the aggregation reaction, we used thioflavin T fluorescence assay, electron microscopy, X-ray diffraction methods, and theoretical modeling. Kinetic experimental data for both insulin samples demonstrated the increase of the lag-time for LysPro insulin at low concentrations of monomers, particularly at 2 and 4 mg/mL, which corresponds to the pharmaceutical concentration. However, the morphology of insulin and LysPro insulin fibrils and their X-ray diffraction patterns is identical. Mature fibrils reach 10-12 μm in length and about 3-4 nm in diameter. The obtained analytical solution allow us to determine the sizes of the primary and secondary nuclei from the experimentally obtained concentration dependences of the time of growth and the ratio of the lag-time duration to the time of growth of amyloid protofibrils. In the case of insulin and LysPro insulin, we have exponential growth of amyloid protofibrils following the "bifurcation + lateral growth" scenario. In accord with the developed theory and the experimental data, we obtained that the size of the primary nucleus is equal to one monomer and the size of the secondary nucleus is zero in both insulin and LysPro insulin.
Collapse
Affiliation(s)
- Olga M Selivanova
- Institute of Protein Research , Russian Academy of Sciences, 4 Institutskaya str., Pushchino, Moscow Region, 142290, Russia
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Žáková L, Kletvíková E, Veverka V, Lepsík M, Watson CJ, Turkenburg JP, Jirácek J, Brzozowski AM. Structural integrity of the B24 site in human insulin is important for hormone functionality. J Biol Chem 2013; 288:10230-40. [PMID: 23447530 DOI: 10.1074/jbc.m112.448050] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Despite the recent first structural insight into the insulin-insulin receptor complex, the role of the C terminus of the B-chain of insulin in this assembly remains unresolved. Previous studies have suggested that this part of insulin must rearrange to reveal amino acids crucial for interaction with the receptor. The role of the invariant Phe(B24), one of the key residues of the hormone, in this process remains unclear. For example, the B24 site functionally tolerates substitutions to D-amino acids but not to L-amino acids. Here, we prepared and characterized a series of B24-modified insulin analogues, also determining the structures of [D-HisB24]-insulin and [HisB24]-insulin. The inactive [HisB24]-insulin molecule is remarkably rigid due to a tight accommodation of the L-His side chain in the B24 binding pocket that results in the stronger tethering of B25-B28 residues to the protein core. In contrast, the highly active [D-HisB24]-insulin is more flexible, and the reverse chirality of the B24C(α) atom swayed the D-His(B24) side chain into the solvent. Furthermore, the pocket vacated by Phe(B24) is filled by Phe(B25), which mimics the Phe(B24) side and main chains. The B25→B24 downshift results in a subsequent downshift of Tyr(B26) into the B25 site and the departure of B26-B30 residues away from the insulin core. Our data indicate the importance of the aromatic L-amino acid at the B24 site and the structural invariance/integrity of this position for an effective binding of insulin to its receptor. Moreover, they also suggest limited, B25-B30 only, unfolding of the C terminus of the B-chain upon insulin activation.
Collapse
Affiliation(s)
- Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Correia M, Neves-Petersen MT, Jeppesen PB, Gregersen S, Petersen SB. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis. PLoS One 2012; 7:e50733. [PMID: 23227203 PMCID: PMC3515625 DOI: 10.1371/journal.pone.0050733] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/24/2012] [Indexed: 12/11/2022] Open
Abstract
In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2)) excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes in protein structure. Structural damage includes insulin dimerization via dityrosine cross-linking or disulphide bond disruption, which affects the hormone's structure and bioactivity.
Collapse
Affiliation(s)
- Manuel Correia
- Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark
| | - Maria Teresa Neves-Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Biotechnology, Chemistry and Environmental Sciences, Aalborg University, Aalborg, Denmark
- * E-mail:
| | - Per Bendix Jeppesen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Søren Gregersen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Steffen B. Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- The Institute for Lasers, Photonics and Biophotonics, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| |
Collapse
|
29
|
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
|