1
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Arghavani P, Badiei A, Ghadami SA, Habibi-Rezaei M, Moosavi-Movahedi F, Delphi L, Moosavi-Movahedi AA. Inhibiting mTTR Aggregation/Fibrillation by a Chaperone-like Hydrophobic Amino Acid-Conjugated SPION. J Phys Chem B 2022; 126:1640-1654. [PMID: 35090112 DOI: 10.1021/acs.jpcb.1c08796] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Transthyretin (TTR) aggregation via misfolding of a mutant or wild-type protein leads to systemic or partial amyloidosis (ATTR). Here, we utilized variable biophysical assays to characterize two distinct aggregation pathways for mTTR (a synthesized monomer TTR incapable of association into a tetramer) at pH 4.3 and also pH 7.4 with agitation, referred to as mTTR aggregation and fibrillation, respectively. The findings suggest that early-stage conformational changes termed monomer activation here determine the aggregation pathway, resulting in developing either amorphous aggregates or well-organized fibrils. Less packed partially unfolded monomers consisting of more non-regular secondary structures that were rapidly produced via a mildly acidic condition form amorphous aggregates. Meanwhile, more hydrophobic and packed monomers consisting of rearranged β sheets and increased helical content developed well-organized fibrils. Conjugating superparamagnetic iron oxide nanoparticles (SPIONs) with leucine and glutamine (L-SPIONs and G-SPIONs in order) via a trimethoxysilane linker provided the chance to study the effect of hydrophobic/hydrophilic surfaces on mTTR aggregation. The results indicated a powerful inhibitory effect of hydrophobic L-SPIONs on both mTTR aggregation and fibrillation. Monomer depletion was introduced as the governing mechanism for inhibiting mTTR aggregation, while a chaperone-like property of L-SPIONs by maintaining an mTTR native structure and adsorbing oligomers suppressed the progression of further fibril formation.
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Affiliation(s)
- Payam Arghavani
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191, Iran
| | - Alireza Badiei
- School of Chemistry, College of Science, University of Tehran, Tehran 1417614411, Iran
| | - Seyyed Abolghasem Ghadami
- Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran 1993893973, Iran
| | - Mehran Habibi-Rezaei
- School of Biology, College of Science, University of Tehran, Tehran 1417614411, Iran
| | | | - Ladan Delphi
- Department of Animal Biology, College of Science, University of Tehran, Tehran 1417614411, Iran
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2
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Ghadami SA, Chia S, Ruggeri FS, Meisl G, Bemporad F, Habchi J, Cascella R, Dobson CM, Vendruscolo M, Knowles TPJ, Chiti F. Transthyretin Inhibits Primary and Secondary Nucleations of Amyloid-β Peptide Aggregation and Reduces the Toxicity of Its Oligomers. Biomacromolecules 2020; 21:1112-1125. [PMID: 32011129 PMCID: PMC7997117 DOI: 10.1021/acs.biomac.9b01475] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
![]()
Alzheimer’s
disease is associated with the deposition of
the amyloid-β peptide (Aβ) into extracellular senile plaques
in the brain. In vitro and in vivo observations have indicated that
transthyretin (TTR) acts as an Aβ scavenger in the brain, but
the mechanism has not been fully resolved. We have monitored the aggregation
process of Aβ40 by thioflavin T fluorescence, in
the presence or absence of different concentrations of preformed seed
aggregates of Aβ40, of wild-type tetrameric TTR (WT-TTR),
and of a variant engineered to be stable as a monomer (M-TTR). Both
WT-TTR and M-TTR were found to inhibit specific steps of the process
of Aβ40 fibril formation, which are primary and secondary
nucleations, without affecting the elongation of the resulting fibrils.
Moreover, the analysis shows that both WT-TTR and M-TTR bind to Aβ40 oligomers formed in the aggregation reaction and inhibit
their conversion into the shortest fibrils able to elongate. Using
biophysical methods, TTR was found to change some aspects of its overall
structure following such interactions with Aβ40 oligomers,
as well as with oligomers of Aβ42, while maintaining
its overall topology. Hence, it is likely that the predominant mechanism
by which TTR exerts its protective role lies in the binding of TTR
to the Aβ oligomers and in inhibiting primary and secondary
nucleation processes, which limits both the toxicity of Aβ oligomers
and the ability of the fibrils to proliferate.
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Affiliation(s)
- Seyyed Abolghasem Ghadami
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Section of Biochemistry, University of Florence, 50134 Florence, Italy
| | - Sean Chia
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Francesco Simone Ruggeri
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Georg Meisl
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Francesco Bemporad
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Section of Biochemistry, University of Florence, 50134 Florence, Italy
| | - Johnny Habchi
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Roberta Cascella
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Section of Biochemistry, University of Florence, 50134 Florence, Italy
| | - Christopher M Dobson
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Michele Vendruscolo
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Tuomas P J Knowles
- Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, U.K.,Department of Physics, Cavendish Laboratory, 19 J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Section of Biochemistry, University of Florence, 50134 Florence, Italy
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3
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Exploration of the Misfolding Mechanism of Transthyretin Monomer: Insights from Hybrid-Resolution Simulations and Markov State Model Analysis. Biomolecules 2019; 9:biom9120889. [PMID: 31861226 PMCID: PMC6995605 DOI: 10.3390/biom9120889] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/13/2019] [Accepted: 12/15/2019] [Indexed: 01/08/2023] Open
Abstract
Misfolding and aggregation of transthyretin (TTR) is widely known to be responsible for a progressive systemic disorder called amyloid transthyretin (ATTR) amyloidosis. Studies suggest that TTR aggregation is initiated by a rate-limiting dissociation of the homo-tetramer into its monomers, which can rapidly misfold and self-assemble into amyloid fibril. Thus, exploring conformational change involved in TTR monomer misfolding is of vital importance for understanding the pathogenesis of ATTR amyloidosis. In this work, microsecond timescale hybrid-resolution molecular dynamics (MD) simulations combined with Markov state model (MSM) analysis were performed to investigate the misfolding mechanism of the TTR monomer. The results indicate that a macrostate with partially unfolded conformations may serve as the misfolded state of the TTR monomer. This misfolded state was extremely stable with a very large equilibrium probability of about 85.28%. With secondary structure analysis, we found the DAGH sheet in this state to be significantly destroyed. The CBEF sheet was relatively stable and sheet structure was maintained. However, the F-strand in this sheet was likely to move away from E-strand and reform a new β-sheet with the H-strand. This observation is consistent with experimental finding that F and H strands in the outer edge drive the misfolding of TTR. Finally, transition pathways from a near native state to this misfolded macrostate showed that the conformational transition can occur either through a native-like β-sheet intermediates or through partially unfolded intermediates, while the later appears to be the main pathway. As a whole, we identified a potential misfolded state of the TTR monomer and elucidated the misfolding pathway for its conformational transition. This work can provide a valuable theoretical basis for understanding of TTR aggregation and the pathogenesis of ATTR amyloidosis at the atomic level.
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4
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Probing conformational changes of monomeric transthyretin with second derivative fluorescence. Sci Rep 2019; 9:10988. [PMID: 31358790 PMCID: PMC6662758 DOI: 10.1038/s41598-019-47230-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/02/2019] [Indexed: 02/06/2023] Open
Abstract
We have studied the intrinsic fluorescence spectra of a monomeric variant of human transthyretin (M-TTR), a protein involved in the transport of the thyroid hormone and retinol and associated with various forms of amyloidosis, extending our analysis to the second order derivative of the spectra. This procedure allowed to identify three peaks readily assigned to Trp41, as the three peaks were also visible in a mutant lacking the other tryptophan (Trp79) and had similar FRET efficiency values with an acceptor molecule positioned at position 10. The wavelength values of the three peaks and their susceptibility to acrylamide quenching revealed that the three corresponding conformers experience different solvent-exposure, polarity of the environment and flexibility. We could monitor the three peaks individually in urea-unfolding and pH-unfolding curves. This revealed changes in the distribution of the corresponding conformers, indicating conformational changes and alterations of the dynamics of the microenvironment that surrounds the associated tryptophan residue in such transitions, but also native-like conformers of such residues in unfolded states. We also found that the amyloidogenic state adopted by M-TTR at mildly low pH has a structural and dynamical microenvironment surrounding Trp41 indistinguishable from that of the fully folded and soluble state at neutral pH.
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5
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Visconti L, Malagrinò F, Gianni S, Toto A. Structural characterization of an on-pathway intermediate and transition state in the folding of the N-terminal SH2 domain from SHP2. FEBS J 2019; 286:4769-4777. [PMID: 31287606 DOI: 10.1111/febs.14990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/29/2019] [Accepted: 07/06/2019] [Indexed: 12/23/2022]
Abstract
Src Homology 2 (SH2) domains are a class of protein domains that present a conserved three-dimensional structure and possess a crucial role in mediating protein-protein interactions. Despite their importance and abundance in the proteome, knowledge about the folding properties of SH2 domain is limited. Here we present an extensive mutational analysis (Φ value analysis) of the folding pathway of the N-SH2 domain of the Src homology region 2 domain-containing phosphatase-2 (SHP2) protein, a 104 residues domain that presents the classical SH2 domain fold (two α-helices flanking a central β-sheet composed of 3-5 antiparallel β-strands), with a fundamental role in mediating the interaction of SHP2 with its substrates and triggering key metabolic pathways in the cell. By analysing folding kinetic data we demonstrated that the folding pathway of N-SH2 presents an obligatory on-pathway intermediate that accumulates during the folding reaction. The production of 24 conservative site-directed variants allowed us to perform a Φ value analysis, by which we could fully characterize the intermediate and the transition state native-like interactions, providing a detailed quantitative analysis of the folding pathway of N-SH2. Results highlight the presence of a hydrophobic nucleus that stabilizes the intermediate, leading to a higher degree of native-like interactions in the transition state. Data are discussed and compared with previous works on SH2 domains.
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Affiliation(s)
- Lorenzo Visconti
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Italy
| | - Francesca Malagrinò
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Italy
| | - Stefano Gianni
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Italy
| | - Angelo Toto
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Istituto di Biologia e Patologia Molecolari del CNR, Sapienza Università di Roma, Italy
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6
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Dasari AKR, Hughes RM, Wi S, Hung I, Gan Z, Kelly JW, Lim KH. Transthyretin Aggregation Pathway toward the Formation of Distinct Cytotoxic Oligomers. Sci Rep 2019; 9:33. [PMID: 30631096 PMCID: PMC6328637 DOI: 10.1038/s41598-018-37230-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/30/2018] [Indexed: 01/12/2023] Open
Abstract
Characterization of small oligomers formed at an early stage of amyloid formation is critical to understanding molecular mechanism of pathogenic aggregation process. Here we identified and characterized cytotoxic oligomeric intermediates populated during transthyretin (TTR) aggregation process. Under the amyloid-forming conditions, TTR initially forms a dimer through interactions between outer strands. The dimers are then associated to form a hexamer with a spherical shape, which serves as a building block to self-assemble into cytotoxic oligomers. Notably, wild-type (WT) TTR tends to form linear oligomers, while a TTR variant (G53A) prefers forming annular oligomers with pore-like structures. Structural analyses of the amyloidogenic intermediates using circular dichroism (CD) and solid-state NMR reveal that the dimer and oligomers have a significant degree of native-like β-sheet structures (35–38%), but with more disordered regions (~60%) than those of native TTR. The TTR variant oligomers are also less structured than WT oligomers. The partially folded nature of the oligomeric intermediates might be a common structural property of cytotoxic oligomers. The higher flexibility of the dimer and oligomers may also compensate for the entropic loss due to the oligomerization of the monomers.
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Affiliation(s)
- Anvesh K R Dasari
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
| | - Robert M Hughes
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
| | - Sungsool Wi
- Center of Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East, Paul Dirac Dr., Tallahassee, FL, 32310, USA
| | - Ivan Hung
- Center of Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East, Paul Dirac Dr., Tallahassee, FL, 32310, USA
| | - Zhehong Gan
- Center of Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East, Paul Dirac Dr., Tallahassee, FL, 32310, USA
| | - Jeffrey W Kelly
- Department of Molecular and Experimental Medicine, the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA.
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7
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Ghadami SA, Bemporad F, Sala BM, Tiana G, Ricagno S, Chiti F. FRET studies of various conformational states adopted by transthyretin. Cell Mol Life Sci 2017; 74:3577-3598. [PMID: 28478513 PMCID: PMC11107560 DOI: 10.1007/s00018-017-2533-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/15/2017] [Accepted: 05/02/2017] [Indexed: 01/01/2023]
Abstract
Transthyretin (TTR) is an extracellular protein able to deposit into well-defined protein aggregates called amyloid, in pathological conditions known as senile systemic amyloidosis, familial amyloid polyneuropathy, familial amyloid cardiomyopathy and leptomeningeal amyloidosis. At least three distinct partially folded states have been described for TTR, including the widely studied amyloidogenic state at mildly acidic pH. Here, we have used fluorescence resonance energy transfer (FRET) experiments in a monomeric variant of TTR (M-TTR) and in its W41F and W79F mutants, taking advantage of the presence of a unique, solvent-exposed, cysteine residue at position 10, that we have labelled with a coumarin derivative (DACM, acceptor), and of the two natural tryptophan residues at positions 41 and 79 (donors). Trp41 is located in an ideal position as it is one of the residues of β-strand C, whose degree of unfolding is debated. We found that the amyloidogenic state at low pH has the same FRET efficiency as the folded state at neutral pH in both M-TTR and W79F-M-TTR, indicating an unmodified Cys10-Trp41 distance. The partially folded state populated at low denaturant concentrations also has a similar FRET efficiency, but other spectroscopic probes indicate that it is distinct from the amyloidogenic state at acidic pH. By contrast, the off-pathway state accumulating transiently during refolding has a higher FRET efficiency, indicating non-native interactions that reduce the Cys10-Trp41 spatial distance, revealing a third distinct conformational state. Overall, our results clarify a negligible degree of unfolding of β-strand C in the formation of the amyloidogenic state and establish the concept that TTR is a highly plastic protein able to populate at least three distinct conformational states.
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Affiliation(s)
- Seyyed Abolghasem Ghadami
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche "Mario Serio", Sezione di Scienze Biochimiche, Università degli Studi di Firenze, Viale Morgagni 50, 50134, Florence, Italy
| | - Francesco Bemporad
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche "Mario Serio", Sezione di Scienze Biochimiche, Università degli Studi di Firenze, Viale Morgagni 50, 50134, Florence, Italy
| | - Benedetta Maria Sala
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Guido Tiana
- Center for Complexity and Biosystems, Department of Physics, Università degli Studi di Milano and INFN, via Celoria 16, 20133, Milan, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Fabrizio Chiti
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche "Mario Serio", Sezione di Scienze Biochimiche, Università degli Studi di Firenze, Viale Morgagni 50, 50134, Florence, Italy.
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8
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Cappelli S, Penco A, Mannini B, Cascella R, Wilson MR, Ecroyd H, Li X, Buxbaum JN, Dobson CM, Cecchi C, Relini A, Chiti F. Effect of molecular chaperones on aberrant protein oligomers in vitro: super-versus sub-stoichiometric chaperone concentrations. Biol Chem 2016; 397:401-15. [PMID: 26812789 DOI: 10.1515/hsz-2015-0250] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/11/2016] [Indexed: 11/15/2022]
Abstract
Living systems protect themselves from aberrant proteins by a network of chaperones. We have tested in vitro the effects of different concentrations, ranging from 0 to 16 μm, of two molecular chaperones, namely αB-crystallin and clusterin, and an engineered monomeric variant of transthyretin (M-TTR), on the morphology and cytotoxicity of preformed toxic oligomers of HypF-N, which represent a useful model of misfolded protein aggregates. Using atomic force microscopy imaging and static light scattering analysis, all were found to bind HypF-N oligomers and increase the size of the aggregates, to an extent that correlates with chaperone concentration. SDS-PAGE profiles have shown that the large aggregates were predominantly composed of the HypF-N protein. ANS fluorescence measurements show that the chaperone-induced clustering of HypF-N oligomers does not change the overall solvent exposure of hydrophobic residues on the surface of the oligomers. αB-crystallin, clusterin and M-TTR can diminish the cytotoxic effects of the HypF-N oligomers at all chaperone concentration, as demonstrated by MTT reduction and Ca2+ influx measurements. The observation that the protective effect is primarily at all concentrations of chaperones, both when the increase in HypF-N aggregate size is minimal and large, emphasizes the efficiency and versatility of these protein molecules.
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9
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Enhancing the Enzymatic Activity of a Heme-Dependent Peroxidase through Genetic Modification. Catalysts 2016. [DOI: 10.3390/catal6110166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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10
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Singh B, Gupta PK, Chauhan V, Chitnis C. Novel and cost-effective refolding of a recombinant receptor binding domain of Plasmodium falciparum EBA-175. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.09.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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The Folding process of Human Profilin-1, a novel protein associated with familial amyotrophic lateral sclerosis. Sci Rep 2015; 5:12332. [PMID: 26227615 PMCID: PMC4521207 DOI: 10.1038/srep12332] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/17/2015] [Indexed: 12/11/2022] Open
Abstract
Human profilin-1 is a novel protein associated with a recently discovered form of familial amyotrophic lateral sclerosis. This urges the characterization of possible conformational states, different from the fully folded state, potentially able to initiate self-assembly. Under native conditions, profilin-1 is monomeric and possesses a well-defined secondary and tertiary structure. When incubated at low pH or with high urea concentrations, profilin-1 remains monomeric but populates unfolded states exhibiting larger hydrodynamic radius and disordered structure, as assessed by dynamic light scattering, far-UV circular dichroism and intrinsic fluorescence. Refolding from the urea-unfolded state was studied at equilibrium and in real-time using a stopped-flow apparatus. The results obtained with intrinsic fluorescence and circular dichroism indicate a single phase without significant changes of the corresponding signals before the major refolding transition. However, such a transition is preceded by a burst phase with an observed increase of ANS fluorescence, which indicates the conversion into a transiently populated collapsed state possessing solvent-exposed hydrophobic clusters. Kinetic analysis reveals that such state has a conformational stability comparable to that of the fully unfolded state. To our knowledge, profilin-1 is the first example of an amyloid-related protein where folding occurs in the absence of thermodynamically stable partially folded states.
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12
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Du K, Sun J, Song X, Song C, Feng W. Enhancement of the solubility and stability of D-amino acid oxidase by fusion to an elastin like polypeptide. J Biotechnol 2015. [PMID: 26216181 DOI: 10.1016/j.jbiotec.2015.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
An elastin-like polypeptide (ELP) was fused to D-amino acid oxidases (DAAO). ELP-DAAO exhibited a better solubility in aqueous solutions than DAAO, and its enzymatic activity is about 1.6 times that of DAAO. The stability of the proteins was investigated by interacting with urea at various concentrations. The circular dichroism and fluorescence spectra were measured. The results demonstrated that that ELP-DAAO exhibited a much better stability than DAAO, and ELP-DAAO has retained the α-helix content with a high percentage even at a high urea concentration. The results of this work have demonstrated that the ELP tag can be utilized to purify DAAO, in the meantime the solubility and stability of the enzyme are improved.
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Affiliation(s)
- Kun Du
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jian Sun
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xiaoqiang Song
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Cuidan Song
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wei Feng
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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