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Biswakarma D, Dey N, Bhattacharya S. Molecular design of amphiphiles for Microenvironment-Sensitive kinetically controlled gelation and their utility in probing alcohol contents. J Colloid Interface Sci 2022; 615:335-345. [DOI: 10.1016/j.jcis.2021.12.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/04/2021] [Accepted: 12/09/2021] [Indexed: 11/26/2022]
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Gorai B, Vashisth H. Progress in Simulation Studies of Insulin Structure and Function. Front Endocrinol (Lausanne) 2022; 13:908724. [PMID: 35795141 PMCID: PMC9252437 DOI: 10.3389/fendo.2022.908724] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/28/2022] [Indexed: 01/02/2023] Open
Abstract
Insulin is a peptide hormone known for chiefly regulating glucose level in blood among several other metabolic processes. Insulin remains the most effective drug for treating diabetes mellitus. Insulin is synthesized in the pancreatic β-cells where it exists in a compact hexameric architecture although its biologically active form is monomeric. Insulin exhibits a sequence of conformational variations during the transition from the hexamer state to its biologically-active monomer state. The structural transitions and the mechanism of action of insulin have been investigated using several experimental and computational methods. This review primarily highlights the contributions of molecular dynamics (MD) simulations in elucidating the atomic-level details of conformational dynamics in insulin, where the structure of the hormone has been probed as a monomer, dimer, and hexamer. The effect of solvent, pH, temperature, and pressure have been probed at the microscopic scale. Given the focus of this review on the structure of the hormone, simulation studies involving interactions between the hormone and its receptor are only briefly highlighted, and studies on other related peptides (e.g., insulin-like growth factors) are not discussed. However, the review highlights conformational dynamics underlying the activities of reported insulin analogs and mimetics. The future prospects for computational methods in developing promising synthetic insulin analogs are also briefly highlighted.
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Chung LHC, Birch DJS, Vyshemirsky V, Ryadnov MG, Rolinski OJ. Tracking Insulin Glycation in Real Time by Time-Resolved Emission Spectroscopy. J Phys Chem B 2019; 123:7812-7817. [PMID: 31441653 DOI: 10.1021/acs.jpcb.9b06363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The application of time-resolved fluorescence sensing to the study of heterogenic biomolecular systems remains challenging because of the complexity of the resulting photophysics. Measuring the time-resolved emission spectroscopy (TRES) spectra can provide a more informative alternative to the modeling of the fluorescence decay that is currently employed. Here, we demonstrate this approach by monitoring real-time changes in intrinsic insulin fluorescence by TRES as a straightforward probe to directly measure kinetics of insulin aggregation and glycation. Our findings hold promise for monitoring the storage of insulin and its application in the control of diabetes and may support the development of more effective therapeutics against amyloidosis.
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Affiliation(s)
- Li Hung C Chung
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance , University of Strathclyde , 107 Rottenrow East , Glasgow G4 0NG , U.K
| | - David J S Birch
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance , University of Strathclyde , 107 Rottenrow East , Glasgow G4 0NG , U.K
| | - Vladislav Vyshemirsky
- School of Mathematics and Statistics , University of Glasgow , Glasgow G12 8QQ , U.K
| | - Maxim G Ryadnov
- National Physical Laboratory , Hampton Road , Teddington TW11 0LW , U.K
| | - Olaf J Rolinski
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance , University of Strathclyde , 107 Rottenrow East , Glasgow G4 0NG , U.K
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Rhinesmith T, Turkette T, Root-Bernstein R. Rapid Non-Enzymatic Glycation of the Insulin Receptor under Hyperglycemic Conditions Inhibits Insulin Binding In Vitro: Implications for Insulin Resistance. Int J Mol Sci 2017; 18:ijms18122602. [PMID: 29207492 PMCID: PMC5751205 DOI: 10.3390/ijms18122602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 01/11/2023] Open
Abstract
The causes of insulin resistance are not well-understood in either type 1 or type 2 diabetes. Insulin (INS) is known to undergo rapid non-enzymatic covalent conjugation to glucose or other sugars (glycation). Because the insulin receptor (IR) has INS-like regions associated with both glucose and INS binding, we hypothesize that hyperglycemic conditions may rapidly glycate the IR, chronically interfering with INS binding. IR peptides were synthesized spanning IR- associated INS-binding regions. Glycation rates of peptides under hyperglycemic conditions were followed over six days using matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. INS conjugated to horse-radish peroxidase was used to determine INS binding to IR peptides in glycated and non-glycated forms. Several IR peptides were glycated up to 14% within days of exposure to 20-60 mM glucose. Rates of IR-peptide glycation were comparable to those of insulin. Glycation of four IR peptides significantly inhibits INS binding to them. Glycation of intact IR also decreases INS binding by about a third, although it was not possible to confirm the glycation sites on the intact IR. Glycation of the IR may therefore provide a mechanism by which INS resistance develops in diabetes. Demonstration of glycation of intact IR in vivo is needed.
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Affiliation(s)
- Tyler Rhinesmith
- Department of Physiology, Michigan State University, 567 Wilson Road, Room 2201, East Lansing, MI 48824, USA.
| | - Thomas Turkette
- Department of Physiology, Michigan State University, 567 Wilson Road, Room 2201, East Lansing, MI 48824, USA.
| | - Robert Root-Bernstein
- Department of Physiology, Michigan State University, 567 Wilson Road, Room 2201, East Lansing, MI 48824, USA.
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Soleymani H, Saboury AA, Moosavi-Movahedi AA, Rahmani F, Maleki J, Yousefinejad S, Maghami P. Vitamin E induces regular structure and stability of human insulin, more intense than vitamin D 3. Int J Biol Macromol 2016; 93:868-878. [PMID: 27642128 DOI: 10.1016/j.ijbiomac.2016.09.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/05/2016] [Accepted: 09/15/2016] [Indexed: 02/06/2023]
Abstract
Changes in human environment and lifestyle over the last century have caused a dramatic increase in the occurrence of diabetes. Research of past decades illustrated that vitamin D and E have a key role in the improvement of diabetes by reducing oxidative stress, protein glycosylation, insulin resistance and also improving beta cell function. Binding properties and conformational changes of human insulin upon interaction with vitamins D3 and E (α-tocopherol) were investigated by spectroscopy, differential scanning calorimetry (DSC) and molecular dynamic simulation. Tyrosine fluorescence quenching studies indicates changes in the human insulin conformation in the presence of vitamins. Binding constants of vitamins D3 and E for human insulin were determined to be 2.7 and 1.5 (×10-5M-1) and the corresponding average numbers of binding sites were determined to be 1.3 and 1.2, respectively. Far- and near-UV circular dichroism studies showed that vitamin E can significantly change the secondary and tertiary structures of human insulin via an increase in the content of α-helix structure. Results of DSC showed that both vitamins D3 and E stabilize the structure of human insulin. Molecular dynamic simulation results indicated that vitamin D3 decreases the helical and strand structural contents of human insulin, but vitamin E stabilizes more regular secondary structures such as helical and strand structural contents as shown by experimental results.
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Affiliation(s)
- Hossein Soleymani
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
| | - Ali A Saboury
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; Center of Excellence in Biothermodynamics, University of Tehran, Tehran, Iran.
| | - Ali A Moosavi-Movahedi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; Center of Excellence in Biothermodynamics, University of Tehran, Tehran, Iran.
| | - Fatemeh Rahmani
- Department of Plant Science, Faculty of Life Science, Tarbiat Modares University, Tehran, Iran.
| | - Javad Maleki
- Department of Biology, Faculty of Basic Science, Hakim Sabzevari University, Sabzevar, Iran.
| | - Saeid Yousefinejad
- Research Center for Health Sciences, Department of Occupational Health, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Parvaneh Maghami
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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Effect of the Freezing Step in the Stability and Bioactivity of Protein-Loaded PLGA Nanoparticles Upon Lyophilization. Pharm Res 2016; 33:2777-93. [PMID: 27444681 DOI: 10.1007/s11095-016-2004-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/18/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE The freezing step in lyophilization is the most determinant for the quality of biopharmaceutics. Using insulin as model of therapeutic protein, our aim was to evaluate the freezing effect in the stability and bioactivity of insulin-loaded PLGA nanoparticles. The performance of trehalose, sucrose and sorbitol as cryoprotectants was evaluated. METHODS Cryoprotectants were co-encapsulated with insulin into PLGA nanoparticles and lyophilized using an optimized cycle with freezing at -80°C, in liquid nitrogen, or ramped cooling at -40°C. Upon lyophilization, the stability of protein structure and in vivo bioactivity were assessed. RESULTS Insulin was co-encapsulated with cryoprotectants resulting in particles of 243-394 nm, zeta potential of -32 to -35 mV, and an association efficiency above 90%. The cryoprotectants were crucial to mitigate the freezing stresses and better stabilize the protein. The insulin structure maintenance was evident and close to 90%. Trehalose co-encapsulated insulin-loaded PLGA nanoparticles demonstrated enhanced hypoglycemic effect, comparatively to nanoparticles without cryoprotectant and added with trehalose, due to a superior insulin stabilization and bioactivity. CONCLUSIONS The freezing process may be detrimental to the structure of protein loaded into nanoparticles, with negative consequences to bioactivity. The co-encapsulation of cryoprotectants mitigated the freezing stresses with benefits to protein bioactivity.
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Fonte P, Lino PR, Seabra V, Almeida AJ, Reis S, Sarmento B. Annealing as a tool for the optimization of lyophilization and ensuring of the stability of protein-loaded PLGA nanoparticles. Int J Pharm 2016; 503:163-73. [DOI: 10.1016/j.ijpharm.2016.03.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/07/2016] [Accepted: 03/09/2016] [Indexed: 11/28/2022]
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Abstract
Protein misfolding and aggregation are associated with more than twenty diseases, such as neurodegenerative diseases and metabolic diseases. The amyloid oligomers and fibrils may induce cell membrane disruption and lead to cell apoptosis. A great number of studies have focused on discovery of amyloid inhibitors which may prevent or treat amyloidosis diseases. Polyphenols have been extensively studied as a class of amyloid inhibitors, with several polyphenols under clinical trials as anti-neurodegenerative drugs. As oxidative intermediates of natural polyphenols, quinones widely exist in medicinal plants or food. In this study, we used insulin as an amyloid model to test the anti-amyloid effects of four simple quinones and four natural anthraquinone derivatives from rhubarb, a traditional herbal medicine used for treating Alzheimer's disease. Our results demonstrated that all eight quinones show inhibitory effects to different extent on insulin oligomerization, especially for 1,4-benzoquinone and 1,4-naphthoquinone. Significantly attenuated oligomerization, reduced amount of amyloid fibrils and reduced hemolysis levels were found after quinones treatments, indicating quinones may inhibit insulin from forming toxic oligomeric species. The results suggest a potential action of native anthraquinone derivatives in preventing protein misfolding diseases, the quinone skeleton may thus be further explored for designing effective anti-amyloidosis compounds.
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Shigenobu H, McNamee CE. The interaction of insulin, glucose, and insulin–glucose mixtures with a phospholipid monolayer. J Colloid Interface Sci 2012; 388:274-81. [DOI: 10.1016/j.jcis.2012.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 07/23/2012] [Accepted: 08/07/2012] [Indexed: 01/17/2023]
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Interaction between insulin and calf thymus DNA, and quantification of insulin and calf thymus DNA by a resonance Rayleigh scattering method. Mikrochim Acta 2012. [DOI: 10.1007/s00604-012-0891-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Wen P, Guo H, Zhang H, Gan B, Ding Q, Ren F. Effect of Glucose on the Lactoferrin’s Conformation and its Effect on MC 3T3-E1 Cell Proliferation. Protein J 2012; 31:300-5. [DOI: 10.1007/s10930-012-9406-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
One of the predominant aims of insulin therapy for diabetes is to appropriately mimic physiological insulin secretion levels and their correlation with glucose concentration in healthy individuals. This report outlines current methods and their limitations in glycemic control and their possible relationship to insufficient knowledge about the structure and dynamics of the insulin hormone itself. Based on recent experimental and computational work, a possible approach to less-invasive insulin administration is sketched.
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Affiliation(s)
- Manuela Koch
- Department of Chemistry, University of Basel, Basel, Switzerland
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Terryn H, Vanhelleputte JP, Maquille A, Tilquin B. Chemical analysis of solid-state irradiated human insulin. Pharm Res 2006; 23:2141-8. [PMID: 16952005 DOI: 10.1007/s11095-006-9053-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 05/05/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. MATERIALS AND METHODS Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. RESULTS After gamma irradiation at 10 kGy, the recovery of insulin was 96.8%; higher molecular weight proteins accounted for 0.35% (relative peak area) and other related compounds (including A21 desamido insulin) represented 1.29%. No major structural changes and no volatile radiolytic compounds were detected. CONCLUSION Human insulin samples irradiated in the solid-state at 10 kGy (gamma rays) and 14 kGy (electron-beam) meet the European Pharmacopoeia requirements and can be considered as quite stable towards radiation from a chemical analysis viewpoint.
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Affiliation(s)
- Hélène Terryn
- Laboratory of Chemical and Physicochemical Analysis of Drugs (CHAM), Université Catholique de Louvain, CHAM 72.30, Avenue E. Mounier, 72, B- 1200, Brussels, Belgium.
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Abstract
We have prepared a small library of amphiphiles, each comprising a polar carbohydrate head group attached through an N-terminal amino acid to a nonpolar pyrene tail group. One of these derivatives is sensitive to the presence of insulin in aqueous media.
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Affiliation(s)
- Sankarprasad Bhuniya
- Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
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Zoete V, Meuwly M, Karplus M. A Comparison of the Dynamic Behavior of Monomeric and Dimeric Insulin Shows Structural Rearrangements in the Active Monomer. J Mol Biol 2004; 342:913-29. [PMID: 15342246 DOI: 10.1016/j.jmb.2004.07.033] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Revised: 07/07/2004] [Accepted: 07/07/2004] [Indexed: 10/26/2022]
Abstract
Molecular dynamics (MD) simulations (5-10ns in length) and normal mode analyses were performed for the monomer and dimer of native porcine insulin in aqueous solution; both starting structures were obtained from an insulin hexamer. Several simulations were done to confirm that the results obtained are meaningful. The insulin dimer is very stable during the simulation and remains very close to the starting X-ray structure; the RMS fluctuations calculated from the MD simulation agree with the experimental B-factors. Correlated motions were found within each of the two monomers; they can be explained by persistent non-bonded interactions and disulfide bridges. The correlated motions between residues B24 and B26 of the two monomers are due to non-bonded interactions between the side-chains and backbone atoms. For the isolated monomer in solution, the A chain and the helix of the B chain are found to be stable during 5ns and 10ns MD simulations. However, the N-terminal and the C-terminal parts of the B chain are very flexible. The C-terminal part of the B chain moves away from the X-ray conformation after 0.5-2.5ns and exposes the N-terminal residues of the A chain that are thought to be important for the binding of insulin to its receptor. Our results thus support the hypothesis that, when monomeric insulin is released from the hexamer (or the dimer in our study), the C-terminal end of the monomer (residues B25-B30) is rearranged to allow binding to the insulin receptor. The greater flexibility of the C-terminal part of the beta chain in the B24 (Phe-->Gly) mutant is in accord with the NMR results. The details of the backbone and side-chain motions are presented. The transition between the starting conformation and the more dynamic structure of the monomers is characterized by displacements of the backbone of Phe B25 and Tyr B26; of these, Phe B25 has been implicated in insulin activation.
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Affiliation(s)
- Vincent Zoete
- Laboratoire de Chimie Biophysique, ISIS/Université Louis Pasteur, 8, allée Gaspard Monge, BP 70028, 67083 Strasbourg Cedex, France
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Abstract
Possible insulin binding sites for D-glucose have been investigated theoretically by docking and molecular dynamics (MD) simulations. Two different docking programs for small molecules were used; Multiple Copy Simultaneous Search (MCSS) and Solvation Energy for Exhaustive Docking (SEED) programs. The configurations resulting from the MCSS search were evaluated with a scoring function developed to estimate the binding free energy. SEED calculations were performed using various values for the dielectric constant of the solute. It is found that scores emphasizing non-polar interactions gave a preferential binding site in agreement with that inferred from recent fluorescence and NMR NOESY experiments. The calculated binding affinity of -1.4 to -3.5 kcal/mol is within the measured range of -2.0 +/- 0.5 kcal/mol. The validity of the binding site is suggested by the dynamical stability of the bound glucose when examined with MD simulations with explicit solvent. Alternative binding sites were found in the simulations and their relative stabilities were estimated. The motions of the bound glucose during molecular dynamics simulations are correlated with the motions of the insulin side chains that are in contact with it and with larger scale insulin motions. These results raise the question of whether glucose binding to insulin could play a role in its activity. The results establish the complementarity of molecular dynamics simulations and normal mode analyses with the search for binding sites proposed with small molecule docking programs.
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Affiliation(s)
- Vincent Zoete
- Laboratoire de Chimie Biophysique, ISIS/Université Louis Pasteur, Strasbourg Cedex, France
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