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Puławski W, Dec R, Dzwolak W. Clues to the Design of Aggregation-Resistant Insulin from Proline Scanning of Highly Amyloidogenic Peptides Derived from the N-Terminal Segment of the A-Chain. Mol Pharm 2024; 21:2025-2033. [PMID: 38525800 PMCID: PMC10988558 DOI: 10.1021/acs.molpharmaceut.4c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/05/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024]
Abstract
Insulin aggregation poses a significant problem in pharmacology and medicine as it occurs during prolonged storage of the hormone and in vivo at insulin injection sites. We have recently shown that dominant forces driving the self-assembly of insulin fibrils are likely to arise from intermolecular interactions involving the N-terminal segment of the A-chain (ACC1-13). Here, we study how proline substitutions within the pilot GIVEQ sequence of this fragment affect its propensity to aggregate in both neutral and acidic environments. In a reasonable agreement with in silico prediction based on the Cordax algorithm, proline substitutions at positions 3, 4, and 5 turn out to be very effective in preventing aggregation according to thioflavin T-fluorescence-based kinetic assay, infrared spectroscopy, and atomic force microscopy (AFM). Since the valine and glutamate side chains within this segment are strongly involved in the interactions with the insulin receptor, we have focused on the possible implications of the Q → P substitution for insulin's stability and interactions with the receptor. To this end, comparative molecular dynamics (MD) simulations of the Q5P mutant and wild-type insulin were carried out for both free and receptor-bound (site 1) monomers. The results point to a mild destabilization of the mutant vis à vis the wild-type monomer, as well as partial preservation of key contacts in the complex between Q5P insulin and the receptor. We discuss the implications of these findings in the context of the design of aggregation-resistant insulin analogues retaining hormonal activity.
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Affiliation(s)
- Wojciech Puławski
- Bioinformatics
Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinski Street 5, 02-106 Warsaw, Poland
| | - Robert Dec
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Dzwolak
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
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2
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Fortunka M, Dec R, Puławski W, Guza M, Dzwolak W. Self-Assembly of Insulin-Derived Chimeric Peptides into Two-Component Amyloid Fibrils: The Role of Coulombic Interactions. J Phys Chem B 2023; 127:6597-6607. [PMID: 37492019 PMCID: PMC10405213 DOI: 10.1021/acs.jpcb.3c00976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/05/2023] [Indexed: 07/27/2023]
Abstract
Canonical amyloid fibrils are composed of covalently identical polypeptide chains. Here, we employ kinetic assays, atomic force microscopy, infrared spectroscopy, circular dichroism, and molecular dynamics simulations to study fibrillization patterns of two chimeric peptides, ACC1-13E8 and ACC1-13K8, in which a potent amyloidogenic stretch derived from the N-terminal segment of the insulin A-chain (ACC1-13) is coupled to octaglutamate or octalysine segments, respectively. While large electric charges prevent aggregation of either peptide at neutral pH, stoichiometric mixing of ACC1-13E8 and ACC1-13K8 triggers rapid self-assembly of two-component fibrils driven by favorable Coulombic interactions. The low-symmetry nonpolar ACC1-13 pilot sequence is crucial in enforcing the fibrillar structure consisting of parallel β-sheets as the self-assembly of free poly-E and poly-K chains under similar conditions results in amorphous antiparallel β-sheets. Interestingly, ACC1-13E8 forms highly ordered fibrils also when paired with nonpolypeptide polycationic amines such as branched polyethylenimine, instead of ACC1-13K8. Such synthetic polycations are more effective in triggering the fibrillization of ACC1-13E8 than poly-K (or poly-E in the case of ACC1-13K8). The high conformational flexibility of these polyamines makes up for the apparent mismatch in periodicity of charged groups. The results are discussed in the context of mechanisms of heterogeneous disease-related amyloidogenesis.
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Affiliation(s)
- Mateusz Fortunka
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Robert Dec
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Puławski
- Bioinformatics
Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinski Street 5, 02-106 Warsaw, Poland
| | - Marcin Guza
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Dzwolak
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
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Dec R, Okoń R, Puławski W, Wacławska M, Dzwolak W. Forced amyloidogenic cooperativity of structurally incompatible peptide segments: Fibrillization behavior of highly aggregation-prone A-chain fragment of insulin coupled to all-L, and alternating L/D octaglutamates. Int J Biol Macromol 2022; 223:362-369. [PMID: 36368353 DOI: 10.1016/j.ijbiomac.2022.11.050] [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: 10/26/2022] [Accepted: 11/06/2022] [Indexed: 11/10/2022]
Abstract
Aggregation of proteins into amyloid fibrils is driven by interactions between relatively small amyloidogenic segments. The interplay between aggregation-prone and aggregation-resistant fragments within a single polypeptide chain remains obscure. Here, we examine fibrillization behavior of two chimeric peptides, ACC1-13E8 and ACC1-13E8(L/D), in which the highly amyloidogenic fragment of insulin (ACC1-13) is extended by an octaglutamate segment composed of all-L (E8), or alternating L/D residues (E8(L/D)). As separate entities, ACC1-13 readily forms fibrils with the infrared features of parallel β-sheet while E8 forms antiparallel β-sheets with the distinct infrared characteristics. This contrasts with the profoundly aggregation-resistant E8(L/D), although L/D patterns have been hypothesized as compatible with aggregated α-sheets. ACC1-13E8 and ACC1-13E8(L/D) are found to be equally prone to fibrillization at low pH, or in the presence of Ca2+ ions. Fibrillar states of both ACC1-13E8 and ACC1-13E8(L/D) reveal the infrared features of highly ordered parallel β-sheet without evidence of β2-aggregates (ACC1-13E8) or α-sheets (ACC1-13E8(L/D)). Hence, the preferred structural pattern of ACC1-13 overrides the tendency of E8 to form antiparallel β-sheets and enforces the fibrillar order in E8(L/D). We demonstrate how the powerful amyloid stretch determines the overall amyloid structure forcing non-amyloidogenic fragments to participate in its native amyloid pattern.
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Affiliation(s)
- Robert Dec
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Róża Okoń
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Puławski
- Bioinformatics Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawinskiego Street 5, 02-106 Warsaw, Poland
| | - Matylda Wacławska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland
| | - Wojciech Dzwolak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteur Street 1, 02-093 Warsaw, Poland; Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska Street 29/37, 01-142 Warsaw, Poland.
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Stutz H. Advances and applications of electromigration methods in the analysis of therapeutic and diagnostic recombinant proteins – A Review. J Pharm Biomed Anal 2022; 222:115089. [DOI: 10.1016/j.jpba.2022.115089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022]
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Puławski W, Dzwolak W. Virtual Quasi-2D Intermediates as Building Blocks for Plausible Structural Models of Amyloid Fibrils from Proteins with Complex Topologies: A Case Study of Insulin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7024-7034. [PMID: 35617668 PMCID: PMC9178918 DOI: 10.1021/acs.langmuir.2c00699] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/08/2022] [Indexed: 06/15/2023]
Abstract
Conformational transitions of globular proteins into amyloid fibrils are complex multistage processes exceedingly challenging to simulate using molecular dynamics (MD). Slow monomer diffusion rates and rugged free energy landscapes disfavor swift self-assembly of orderly amyloid architectures within timescales accessible to all-atom MD. Here, we conduct a multiscale MD study of the amyloidogenic self-assembly of insulin: a small protein with a complex topology defined by two polypeptide chains interlinked by three disulfide bonds. To avoid kinetic traps, unconventional preplanarized insulin conformations are used as amyloid building blocks. These starting conformers generated through uniaxial compression of the native monomer in various spatial directions represent 6 distinct (out of 16 conceivable) two-dimensional (2D) topological classes varying in N-/C-terminal segments of insulin's A- and B-chains being placed inside or outside of the central loop constituted by the middle sections of both chains and Cys7A-Cys7B/Cys19B-Cys20A disulfide bonds. Simulations of the fibrillar self-assembly are initiated through a biased in-register alignment of two, three, or four layers of flat conformers belonging to a single topological class. The various starting topologies are conserved throughout the self-assembly process resulting in polymorphic amyloid fibrils varying in structural features such as helical twist, presence of cavities, and overall stability. Some of the protofilament structures obtained in this work are highly compatible with the earlier biophysical studies on insulin amyloid and high-resolution studies on insulin-derived amyloidogenic peptide models postulating the presence of steric zippers. Our approach provides in silico means to study amyloidogenic tendencies and viable amyloid architectures of larger disulfide-constrained proteins with complex topologies.
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Affiliation(s)
- Wojciech Puławski
- Institute
of High Pressure Physics, Polish Academy
of Sciences, 29/37 Sokołowska
Str., 01-142 Warsaw, Poland
| | - Wojciech Dzwolak
- Institute
of High Pressure Physics, Polish Academy
of Sciences, 29/37 Sokołowska
Str., 01-142 Warsaw, Poland
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., 02-093 Warsaw, Poland
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Khaibrakhmanova D, Nikiforova A, Li Z, Sedov I. Effect of ligands with different affinity on albumin fibril formation. Int J Biol Macromol 2022; 204:709-717. [PMID: 35134455 DOI: 10.1016/j.ijbiomac.2022.01.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/11/2022] [Accepted: 01/29/2022] [Indexed: 11/18/2022]
Abstract
The effect of binding of several ligands to bovine serum albumin on the kinetics of fibril formation at denaturing conditions is studied. The considered ligands are clinical drugs with different binding constants to albumin: relatively strong binders (naproxen, ibuprofen, warfarin with 105 to 107 binding constant values) and weak binders (isoniazid, ranitidine with 103 to 104 binding constant values). The data of thioflavin fluorescence binding assay, Congo red binding assay, and circular dichroism spectroscopy indicate ligand concentration-dependent suppression of fibril formation in the presence of strong binders and no effects in the presence of weak binders. Analysis of kinetic curves shows no induction lag associated with fibril nucleation and the first-order kinetics of fibril formation with respect to albumin concentration for all the studied systems. Using DSC method, the fractions of unfolded albumin at incubation temperature were determined for each albumin-ligand system and ligand concentration. Their magnitudes ranging from 0 to 1 correlate with the initial rates of fibril formation and with equilibrium concentrations of fibrils formed in the system after incubation for at least 120 min. The results indicate that fibrils are formed from partially or completely denatured albumin form with the rate proportional to the fraction of this form. Strong albumin binders act as thermodynamic inhibitors of fibrillation shifting the unfolding equilibrium to the side of the native ligand-bound protein.
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Affiliation(s)
| | - Alena Nikiforova
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Ziying Li
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Igor Sedov
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia.
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Multiscale Modeling of Amyloid Fibrils Formed by Aggregating Peptides Derived from the Amyloidogenic Fragment of the A-Chain of Insulin. Int J Mol Sci 2021; 22:ijms222212325. [PMID: 34830214 PMCID: PMC8621111 DOI: 10.3390/ijms222212325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/08/2021] [Accepted: 11/12/2021] [Indexed: 12/31/2022] Open
Abstract
Computational prediction of molecular structures of amyloid fibrils remains an exceedingly challenging task. In this work, we propose a multi-scale modeling procedure for the structure prediction of amyloid fibrils formed by the association of ACC1-13 aggregation-prone peptides derived from the N-terminal region of insulin’s A-chain. First, a large number of protofilament models composed of five copies of interacting ACC1-13 peptides were predicted by application of CABS-dock coarse-grained (CG) docking simulations. Next, the models were reconstructed to all-atom (AA) representations and refined during molecular dynamics (MD) simulations in explicit solvent. The top-scored protofilament models, selected using symmetry criteria, were used for the assembly of long fibril structures. Finally, the amyloid fibril models resulting from the AA MD simulations were compared with atomic force microscopy (AFM) imaging experimental data. The obtained results indicate that the proposed multi-scale modeling procedure is capable of predicting protofilaments with high accuracy and may be applied for structure prediction and analysis of other amyloid fibrils.
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