1
|
Hall D. Biophysical Reviews' "Meet the Editors Series": a profile of Damien Hall. Biophys Rev 2023; 15:1883-1896. [PMID: 38192343 PMCID: PMC10771549 DOI: 10.1007/s12551-023-01176-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2023] [Indexed: 01/10/2024] Open
Abstract
This piece introduces Damien Hall, Chief Editor of the Biophysical Reviews journal since 2019. Currently working as an Assistant Professor at Kanazawa University, the author describes his association with the journal along with some parts of his family history and academic journey.
Collapse
Affiliation(s)
- Damien Hall
- WPI Nano Life Science Institute, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1164 Japan
| |
Collapse
|
2
|
Hall D. MIL-CELL: a tool for multi-scale simulation of yeast replication and prion transmission. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:673-704. [PMID: 37670150 PMCID: PMC10682183 DOI: 10.1007/s00249-023-01679-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 09/07/2023]
Abstract
The single-celled baker's yeast, Saccharomyces cerevisiae, can sustain a number of amyloid-based prions, the three most prominent examples being [URE3], [PSI+], and [PIN+]. In the laboratory, haploid S. cerevisiae cells of a single mating type can acquire an amyloid prion in one of two ways (i) spontaneous nucleation of the prion within the yeast cell, and (ii) receipt via mother-to-daughter transmission during the cell division cycle. Similarly, prions can be lost due to (i) dissolution of the prion amyloid by its breakage into non-amyloid monomeric units, or (ii) preferential donation/retention of prions between the mother and daughter during cell division. Here we present a computational tool (Monitoring Induction and Loss of prions in Cells; MIL-CELL) for modelling these four general processes using a multiscale approach describing both spatial and kinetic aspects of the yeast life cycle and the amyloid-prion behavior. We describe the workings of the model, assumptions upon which it is based and some interesting simulation results pertaining to the wave-like spread of the epigenetic prion elements through the yeast population. MIL-CELL is provided as a stand-alone GUI executable program for free download with the paper. MIL-CELL is equipped with a relational database allowing all simulated properties to be searched, collated and graphed. Its ability to incorporate variation in heritable properties means MIL-CELL is also capable of simulating loss of the isogenic nature of a cell population over time. The capability to monitor both chronological and reproductive age also makes MIL-CELL potentially useful in studies of cell aging.
Collapse
Affiliation(s)
- Damien Hall
- WPI Nano Life Science Institute, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa, 920-1164, Japan.
| |
Collapse
|
3
|
Zhou X, Sinkjær AW, Zhang M, Pinholt HD, Nielsen HM, Hatzakis NS, van de Weert M, Foderà V. Heterogeneous and Surface-Catalyzed Amyloid Aggregation Monitored by Spatially Resolved Fluorescence and Single Molecule Microscopy. J Phys Chem Lett 2023; 14:912-919. [PMID: 36669144 DOI: 10.1021/acs.jpclett.2c03400] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Amyloid aggregation is associated with many diseases and may also occur in therapeutic protein formulations. Addition of co-solutes is a key strategy to modulate the stability of proteins in pharmaceutical formulations and select inhibitors for drug design in the context of diseases. However, the heterogeneous nature of this multicomponent system in terms of structures and mechanisms poses a number of challenges for the analysis of the chemical reaction. Using insulin as protein system and polysorbate 80 as co-solute, we combine a spatially resolved fluorescence approach with single molecule microscopy and machine learning methods to kinetically disentangle the different contributions from multiple species within a single aggregation experiment. We link the presence of interfaces to the degree of heterogeneity of the aggregation kinetics and retrieve the rate constants and underlying mechanisms for single aggregation events. Importantly, we report that the mechanism of inhibition of the self-assembly process depends on the details of the growth pathways of otherwise macroscopically identical species. This information can only be accessed by the analysis of single aggregate events, suggesting our method as a general tool for a comprehensive physicochemical characterization of self-assembly reactions.
Collapse
Affiliation(s)
- Xin Zhou
- Drug Delivery and Biophysics of Biopharmaceuticals and Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery), Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders Wilgaard Sinkjær
- Drug Delivery and Biophysics of Biopharmaceuticals and Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery), Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Min Zhang
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
- Nano-Science Center, University of Copenhagen Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Henrik Dahl Pinholt
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Hanne Mørck Nielsen
- Drug Delivery and Biophysics of Biopharmaceuticals and Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery), Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Nano-Science Center, University of Copenhagen Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Nikos S Hatzakis
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
- Nano-Science Center, University of Copenhagen Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Marco van de Weert
- Drug Delivery and Biophysics of Biopharmaceuticals and Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery), Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Nano-Science Center, University of Copenhagen Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Vito Foderà
- Drug Delivery and Biophysics of Biopharmaceuticals and Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery), Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Nano-Science Center, University of Copenhagen Universitetsparken 5, 2100 Copenhagen, Denmark
| |
Collapse
|
4
|
Hall D. A simple method for modeling amyloid kinetics featuring position biased fiber breakage. Biophys Physicobiol 2020; 17:30-35. [PMID: 33110736 PMCID: PMC7550252 DOI: 10.2142/biophysico.bsj-2020003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/12/2020] [Indexed: 12/01/2022] Open
Abstract
A mathematical model of amyloid fiber formation is described that is able to simply specify different rates of fiber breakage at internal versus end regions. This Note presents the derivation of the relevant equations and provides results showing the dramatic effects of position biased fiber breakage on the kinetics of amyloid growth.
Collapse
Affiliation(s)
- Damien Hall
- Laboratory of Biochemistry and Genetics, NIDDK, NIH, Bethesda, MD 20892-0830, USA.,Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.,Present address: International Center, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi 466-8555, Japan
| |
Collapse
|
5
|
Hall D. On the nature of the optimal form of the holdase-type chaperone stress response. FEBS Lett 2019; 594:43-66. [PMID: 31432502 DOI: 10.1002/1873-3468.13580] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 11/08/2022]
Abstract
The holdase paradigm of chaperone action involves preferential binding by the chaperone to the unfolded protein state, thereby preventing it from either, associating with other unstable proteins (to form large dysfunctional aggregates), or being degraded by the proteolytic machinery of the cell/organism. In this paper, we examine the necessary physical constraints imposed upon the holdase chaperone response in a cell-like environment and use these limitations to comment on the likely nature of the optimal form of chaperone response in vivo.
Collapse
Affiliation(s)
- Damien Hall
- Laboratory of Biochemistry and Genetics, NIDDK, NIH, Bethesda, MD, USA.,Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| |
Collapse
|
6
|
Ionic liquids and protein folding-old tricks for new solvents. Biophys Rev 2019; 11:209-225. [PMID: 30888574 DOI: 10.1007/s12551-019-00509-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 02/15/2019] [Indexed: 01/19/2023] Open
Abstract
One important aspect of the green chemistry revolution has been the use of ionic liquids as the solvent in liquid-phase enzymatic catalysis. An essential requirement for protein enzyme function is the correct folding of the polypeptide chain into its functional "native" state. Quantitative assessment of protein structure may be carried out either empirically, or by using model-based characterization procedures, in which the parameters are defined in terms of a standard reference state. In this short note, we briefly outline the nature of the parameters associated with different empirical and model-based characterization procedures and point out factors which affect their interpretation when using a base solvent different from water. This review principally describes arguments developed by Wakayama et al., Protein Solubility and Amorphous Aggregation: From Academic Research to Applications in Drug Discovery and Bioindustry, 2019, edited by Y. Kuroda and F. Arisaka; CMC Publishing House. Sections of that work are translated from the original Japanese and republished here with the full permission of CMC Publishing Corporation.
Collapse
|
7
|
Zhao R, So M, Maat H, Ray NJ, Arisaka F, Goto Y, Carver JA, Hall D. Measurement of amyloid formation by turbidity assay-seeing through the cloud. Biophys Rev 2016; 8:445-471. [PMID: 28003859 PMCID: PMC5135725 DOI: 10.1007/s12551-016-0233-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 10/11/2016] [Indexed: 12/12/2022] Open
Abstract
Detection of amyloid growth is commonly carried out by measurement of solution turbidity, a low-cost assay procedure based on the intrinsic light scattering properties of the protein aggregate. Here, we review the biophysical chemistry associated with the turbidimetric assay methodology, exploring the reviewed literature using a series of pedagogical kinetic simulations. In turn, these simulations are used to interrogate the literature concerned with in vitro drug screening and the assessment of amyloid aggregation mechanisms.
Collapse
Affiliation(s)
- Ran Zhao
- Research School of Chemistry, Australian National University, Acton ACT, 2601, Australia
| | - Masatomo So
- Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Hendrik Maat
- Research School of Chemistry, Australian National University, Acton ACT, 2601, Australia
| | - Nicholas J Ray
- Research School of Chemistry, Australian National University, Acton ACT, 2601, Australia
| | - Fumio Arisaka
- College of Bio-resource Sciences, Nihon University, Chiyoda-ku, Tokyo, 102-8275, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - John A Carver
- Research School of Chemistry, Australian National University, Acton ACT, 2601, Australia
| | - Damien Hall
- Research School of Chemistry, Australian National University, Acton ACT, 2601, Australia. .,Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
8
|
Vall-Sagarra A, McMicken B, Nonell S, Brancaleon L. Effects of Visible-Light Irradiation of Protoporphyrin IX on the Self-Assembly of Tubulin Heterodimers. Chemphyschem 2016; 17:3269-3282. [PMID: 27490308 PMCID: PMC5177992 DOI: 10.1002/cphc.201600629] [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: 06/13/2016] [Indexed: 11/10/2022]
Abstract
The formation and the effects of laser irradiation of the complex formed by protoporphyrin IX (PPIX) and tubulin was investigated. We have used tubulin as a model protein to investigate whether docked photoactive ligands can affect the structure and function of polypeptides upon exposure to visible light. We observed that laser irradiation in the Soret band prompts bleaching of the PPIX, which is accompanied by a sharp decrease in the intensity and average fluorescence lifetime of the protein (dominated by the four tryptophan residues of the tubulin monomer). The kinetics indicate non-trivial effects and suggest that the photosensitization of the PPIX bound to tubulin prompts structural alterations of the protein. These modifications were also observed through changes in the energy transfer between Trp residues and PPIX. The results suggest that laser irradiation produces localized partial unfolding of tubulin and that the changes prompt modification of the formation of microtubules in vitro. Measurements of singlet oxygen formation were inconclusive in determining whether the changes are prompted by reactive oxygen species or other excited state mechanisms.
Collapse
Affiliation(s)
- Alicia Vall-Sagarra
- Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
| | - Brady McMicken
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
| | - Santi Nonell
- Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain
| | - Lorenzo Brancaleon
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA.
| |
Collapse
|
9
|
Hall D, Zhao R, So M, Adachi M, Rivas G, Carver JA, Goto Y. Recognizing and analyzing variability in amyloid formation kinetics: Simulation and statistical methods. Anal Biochem 2016; 510:56-71. [PMID: 27430932 DOI: 10.1016/j.ab.2016.07.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/11/2016] [Accepted: 07/13/2016] [Indexed: 12/24/2022]
Abstract
We examine the phenomenon of variability in the kinetics of amyloid formation and detail methods for its simulation, identification and analysis. Simulated data, reflecting intrinsic variability, were produced using rate constants, randomly sampled from a pre-defined distribution, as parameters in an irreversible nucleation-growth kinetic model. Simulated kinetic traces were reduced in complexity through description in terms of three characteristic parameters. Practical methods for assessing convergence of the reduced parameter distributions were introduced and a bootstrap procedure was applied to determine convergence for different levels of intrinsic variation. Statistical methods for assessing the significance of shifts in parameter distributions, relating to either change in parameter mean or distribution shape, were tested. Robust methods for analyzing and interpreting kinetic data possessing significant intrinsic variance will allow greater scrutiny of the effects of anti-amyloid compounds in drug trials.
Collapse
Affiliation(s)
- Damien Hall
- Research School of Chemistry, Australian National University, Acton ACT 2601, Australia; Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka 565-0871 Japan.
| | - Ran Zhao
- Research School of Chemistry, Australian National University, Acton ACT 2601, Australia
| | - Masatomo So
- Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka 565-0871 Japan
| | - Masayuki Adachi
- Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka 565-0871 Japan
| | - Germán Rivas
- Centro de Investigaciones Biológicas, CSIC, 28006 Madrid, Spain
| | - John A Carver
- Research School of Chemistry, Australian National University, Acton ACT 2601, Australia
| | - Yuji Goto
- Institute for Protein Research, Osaka University, 3-1- Yamada-oka, Suita, Osaka 565-0871 Japan
| |
Collapse
|
10
|
McMicken B, Thomas RJ, Brancaleon L. Partial Unfolding of Tubulin Heterodimers Induced by Two-Photon Excitation of Bound meso-Tetrakis(sulfonatophenyl)porphyrin. J Phys Chem B 2016; 120:3653-65. [PMID: 27035156 DOI: 10.1021/acs.jpcb.6b02055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The water-soluble porphyrin meso-tetrakis(p-sulfonatophenyl)porphyrin (TSPP) can be noncovalently bound to tubulin and used as a photosensitizer, which upon irradiation triggers photochemical reactions that lead to conformational changes of the protein. These conformational changes in turn inhibit tubulin's primary function of polymerizing into microtubules. We explored the possibility of using two-photon excitation of the bound porphyrin to induce photosensitized protein unfolding. Although TSPP has a relatively low cross section (∼30 GM) our results did find that two-photon excitation of the ligand causes partial unfolding of the tubulin host and the inhibition of the in vitro formation of microtubules. Conversely, irradiating tubulin alone caused no such effects despite the large irradiance per pulse (97-190 GW/cm(2)). The conformational changes were characterized using spectroscopic studies and provide a promising protocol for the future application of non-native photosensitization of proteins.
Collapse
Affiliation(s)
- Brady McMicken
- The University of Texas at San Antonio , Department of Physics and Astronomy, One UTSA Circle, San Antonio, Texas 78249, United States.,Human Effectiveness Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, 711th Human Performance Wing, Joint Base San Antonio , JBSA Fort Sam Houston, Texas 78234, United States
| | - Robert J Thomas
- Human Effectiveness Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, 711th Human Performance Wing, Joint Base San Antonio , JBSA Fort Sam Houston, Texas 78234, United States
| | - Lorenzo Brancaleon
- The University of Texas at San Antonio , Department of Physics and Astronomy, One UTSA Circle, San Antonio, Texas 78249, United States
| |
Collapse
|
11
|
Hall D, Zhao R, Dehlsen I, Mannix EJ, Williams SR, Arisaka F, Goto Y, Carver JA. Protein aggregate turbidity: Simulation of turbidity profiles for mixed-aggregation reactions. Anal Biochem 2016; 498:78-94. [PMID: 26763936 DOI: 10.1016/j.ab.2015.11.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 11/27/2015] [Accepted: 11/30/2015] [Indexed: 12/11/2022]
Abstract
Due to their colloidal nature, all protein aggregates scatter light in the visible wavelength region when formed in aqueous solution. This phenomenon makes solution turbidity, a quantity proportional to the relative loss in forward intensity of scattered light, a convenient method for monitoring protein aggregation in biochemical assays. Although turbidity is often taken to be a linear descriptor of the progress of aggregation reactions, this assumption is usually made without performing the necessary checks to provide it with a firm underlying basis. In this article, we outline utilitarian methods for simulating the turbidity generated by homogeneous and mixed-protein aggregation reactions containing fibrous, amorphous, and crystalline structures. The approach is based on a combination of Rayleigh-Gans-Debye theory and approximate forms of the Mie scattering equations.
Collapse
Affiliation(s)
- Damien Hall
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia; Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Ran Zhao
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia
| | - Ian Dehlsen
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia
| | - Evelyn Jane Mannix
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia
| | - Steven R Williams
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia
| | - Fumio Arisaka
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8501, Japan; Advanced Materials Science Center, College of Bioresource Sciences, Nihon University, Chiyoda-ku, Tokyo 102-8275, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - John A Carver
- Research School of Chemistry, Australian National University, Acton, ACT 2601, Australia
| |
Collapse
|
12
|
Kilner J, Corfe BM, McAuley MT, Wilkinson SJ. A deterministic oscillatory model of microtubule growth and shrinkage for differential actions of short chain fatty acids. MOLECULAR BIOSYSTEMS 2016; 12:93-101. [DOI: 10.1039/c5mb00211g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Short-chain fatty acids have distinct effects on cytoskeletal proteins at the level of expression and organisation. We report a new oscillatory, deterministic model which accounts for different actions and predicts response according to fatty acid chain length.
Collapse
Affiliation(s)
- Josephine Kilner
- Biological and Systems Engineering Group
- ChELSI Institute
- Department of Chemical and Biological Engineering
- University of Sheffield S1 3JD
- UK
| | - Bernard M. Corfe
- Molecular Gastroenterology Research Group
- Academic Unit of Surgical Oncology
- Department of Oncology
- University of Sheffield
- The Medical School
| | | | - Stephen J. Wilkinson
- Biological and Systems Engineering Group
- ChELSI Institute
- Department of Chemical and Biological Engineering
- University of Sheffield S1 3JD
- UK
| |
Collapse
|
13
|
Hall D, Edskes H. Computational modeling of the relationship between amyloid and disease. Biophys Rev 2012; 4:205-222. [PMID: 23495357 PMCID: PMC3595053 DOI: 10.1007/s12551-012-0091-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 06/21/2012] [Indexed: 01/29/2023] Open
Abstract
Amyloid is a title conferred upon a special type of linear protein aggregate that exhibits a common set of structural features and dye binding capabilities. The formation of amyloid is associated with over twenty-seven distinct human diseases which are collectively referred to as the amyloidoses. Although there is great diversity amongst the amyloidoses with regard to the polypeptide monomeric precursor, targeted tissues and the nature and time course of disease development, the common underlying link of a structurally similar amyloid aggregate has prompted the search for a unified theory of disease progression in which amyloid production is the central element. Computational modeling has allowed the formulation and testing of scientific hypotheses for exploring this relationship. However, the majority of computational studies on amyloid aggregation are pitched at the atomistic level of description, in simple ideal solution environments, with simulation time scales of the order of microseconds and system sizes limited to a hundred monomers (or less). The experimental reality is that disease related amyloid aggregation processes occur in extremely complex reaction environments (i.e. the human body), over time-scales of months to years with monitoring of the reaction achieved using extremely coarse or indirect experimental markers that yield little or no atomistic insight. Clearly a substantial gap exists between computational and experimental communities with a deficit of 'useful' computational methodology that can be directly related to available markers of disease progression. This Review will place its focus on the development of these latter types of computational models and discuss them in relation to disease onset and progression.
Collapse
Affiliation(s)
- Damien Hall
- Institute of Basic Medical Science, University of Tsukuba, Lab 225-B, Building D. 1-1-1 Tennodai, Tsukuba-shi, Ibaraki-ken 305-8577 Japan
| | - Herman Edskes
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830 USA
| |
Collapse
|
14
|
Hall D. Semi-automated methods for simulation and measurement of amyloid fiber distributions obtained from transmission electron microscopy experiments. Anal Biochem 2012; 421:262-77. [DOI: 10.1016/j.ab.2011.10.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 10/04/2011] [Accepted: 10/04/2011] [Indexed: 11/27/2022]
|
15
|
Kilner J, Corfe BM, Wilkinson SJ. Modelling the microtubule: towards a better understanding of short-chain fatty acid molecular pharmacology. MOLECULAR BIOSYSTEMS 2011; 7:975-83. [DOI: 10.1039/c0mb00281j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
16
|
Valdez R, Johnson EM, Belcher JA, Fuini JF, Brancaleon L. Porphyrins affect the self-assembly of tubulin in solution. Biophys Chem 2009; 145:98-104. [PMID: 19819610 DOI: 10.1016/j.bpc.2009.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 09/16/2009] [Accepted: 09/16/2009] [Indexed: 10/20/2022]
Abstract
Self-assembly of tubulin heterodimers in solution has been studied in the past to predict the effects that ligands and/or conformational changes have on the formation of tubulin filaments. Self-assembly of tubulin in solution has produced formations similar to cellular microtubules (MTs). The present study reports on the effects that two porphyrins (protoporphyrin IX, PPIX and tetrakis(4-sulfonatophenyl)porphyrin, TPPS) produce on the self-assembly of tubulin alpha,beta-heterodimers in buffer solution. The study shows that, when incubated simultaneously with MT-stabilizing ligands (i.e., paclitaxel and guanosine triphosphate, GTP), porphyrins do not affect the ability of tubulin to form MT. However, if paclitaxel and GTP are added after tubulin has been allowed to self-assemble in the presence of either porphyrin, the ability to form MT-like structures is reduced or suppressed. We suggest that this effect is due to the formation of porphyrin-mediated aggregates that cannot be broken or elongated by the addition of GTP or paclitaxel.
Collapse
Affiliation(s)
- Rolando Valdez
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | | | | | | | | |
Collapse
|
17
|
Hall D, Hirota N. Multi-scale modelling of amyloid formation from unfolded proteins using a set of theory derived rate constants. Biophys Chem 2009; 140:122-8. [DOI: 10.1016/j.bpc.2008.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 11/17/2008] [Accepted: 11/17/2008] [Indexed: 01/05/2023]
|
18
|
Jeong S, Hollingsworth JA. Polymerization of nanocrystal quantum dot-tubulin bioconjugates. IEEE Trans Nanobioscience 2006; 5:239-45. [PMID: 17181022 DOI: 10.1109/tnb.2006.886561] [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] [Indexed: 11/08/2022]
Abstract
Nanocrystal quantum dot (NQD)-tubulin bioconjugates were prepared using a two-step crosslinking procedure. NQD-decorated microtubules were successfully polymerized directly from the NQD-tubulin conjugates to form nonaggregated, full-length (several micrometers) biopolymers. However, polymerization kinetics were slowed in comparison with unmodified tubulin and tubulin modified with small-molecule dyes or biotin. Association with the relatively large nanocrystals, therefore, interferes to some extent with tubulin's ability to polymerize. These results suggest that before NQDs are used extensively as fluorescent labels in studies of biomolecular activity, the impact of NQD bioconjugation must be well understood.
Collapse
Affiliation(s)
- Sohee Jeong
- Los Alamos National Laboratory Chemistry Division, Los Alamos, NM 87545, USA.
| | | |
Collapse
|
19
|
Bonfils C, Bec N, Lacroix B, Harricane MC, Larroque C. Kinetic analysis of tubulin assembly in the presence of the microtubule-associated protein TOGp. J Biol Chem 2006; 282:5570-81. [PMID: 17178729 PMCID: PMC2238798 DOI: 10.1074/jbc.m605641200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The microtubule-associated protein TOGp, which belongs to a widely distributed protein family from yeasts to humans, is highly expressed in human tumors and brain tissue. From purified components we have determined the effect of TOGp on thermally induced tubulin association in vitro in the presence of 1 mm GTP and 3.4 m glycerol. Physicochemical parameters describing the mechanism of tubulin polymerization were deduced from the kinetic curves by application of the classical theoretical models of tubulin assembly. We have calculated from the polymerization time curves a range of parameters characteristic of nucleation, elongation, or steady state phase. In addition, the tubulin subunits turnover at microtubule ends was deduced from tubulin GTPase activity. For comparison, parallel experiments were conducted with colchicine and taxol, two drugs active on microtubules and with tau, a structural microtubule-associated protein from brain tissue. TOGp, which decreases the nucleus size and the tenth time of the reaction (the time required to produce 10% of the final amount of polymer), shortens the nucleation phase of microtubule assembly. In addition, TOGp favors microtubule formation by increasing the apparent first order rate constant of elongation. Moreover, TOGp increases the total amount of polymer by decreasing the tubulin critical concentration and by inhibiting depolymerization during the steady state of the reaction.
Collapse
Affiliation(s)
- Claude Bonfils
- INSERM, EMI 229, CRLC Val d'Aurelle, 34298 Montpellier, France.
| | | | | | | | | |
Collapse
|
20
|
Boal AK, Tellez H, Rivera SB, Miller NE, Bachand GD, Bunker BC. The stability and functionality of chemically crosslinked microtubules. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2006; 2:793-803. [PMID: 17193124 DOI: 10.1002/smll.200500381] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A variety of bifunctional crosslinking agents have been explored for stabilizing microtubule shuttles used for the active transport of nanomaterials in artificial environments. Crosslinking agents that target amine residues form intertubulin crosslinks that produce crosslinked microtubules (CLMTs) with structural and functional lifetimes that can be up to four times as long as those achieved with taxol stabilization. Such CLMTs are stable at temperatures down to -10 degrees C, are resistant to depolymerization induced by metal ions such as Ca2+, and yet continue to be adsorbed and transported by self-assembled monolayers containing the motor protein kinesin. However, crosslinkers that target cysteine residues depolymerize the MTs, probably by interfering with the guanosine triphosphate binding site. The impact of crosslink attributes, including terminal group chemistry, chain length, crosslink density, and specific location on the tubulin surface, on microtubule stability and functionality are discussed.
Collapse
Affiliation(s)
- Andrew K Boal
- Sandia National Laboratory, MS 1413, PO Box 5800, Albuquerque, NM 87185, USA
| | | | | | | | | | | |
Collapse
|
21
|
Hall D, Minton AP. Turbidity as a probe of tubulin polymerization kinetics: A theoretical and experimental re-examination. Anal Biochem 2005; 345:198-213. [PMID: 16129407 DOI: 10.1016/j.ab.2005.07.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 07/07/2005] [Accepted: 07/12/2005] [Indexed: 10/25/2022]
Abstract
We report here an examination of the validity of the experimental practice of using solution turbidity to study the polymerization kinetics of microtubule formation. The investigative approach proceeds via numerical solution of model rate equations to yield the time dependence of each microtubule species, followed by the calculation of the time- and wavelength-dependent turbidity generated by the calculated distribution of rod lengths. The wavelength dependence of the turbidity along the time course is analyzed to search for generalized kinetic regimes that satisfy a constant proportionality relationship between the observed turbidity and the weight concentration of polymerized tubulin. An empirical analysis, which permits valid interpretation of turbidity data for distributions of microtubules that are not long relative to the wavelength of incident light, is proposed. The basic correctness of the simulation work is shown by the analysis of the experimental time dependence of the turbidity wavelength exponent for microtubule formation in taxol-supplemented 0.1 M Pipes buffer (1 mM GTP, 1 mM EGTA, 1 mM MgSO4, pH 6.4). We believe that the general findings and principles outlined here are applicable to studies of other fibril-forming systems that use turbidity as a marker of polymerization progress.
Collapse
Affiliation(s)
- Damien Hall
- Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK.
| | | |
Collapse
|
22
|
Hall D, Hirota N, Dobson CM. A toy model for predicting the rate of amyloid formation from unfolded protein. J Mol Biol 2005; 351:195-205. [PMID: 15993421 DOI: 10.1016/j.jmb.2005.05.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 04/05/2005] [Accepted: 05/03/2005] [Indexed: 11/26/2022]
Abstract
We develop a toy model for predicting the rate of amyloid formation from an unfolded polypeptide. The model assumes irreversible amyloid growth, employs a collision encounter scheme and uses a Gaussian chain approximation to describe the polypeptide sequence. A principal feature of the model is its dependence on a number of key sequence residues whose correct placement, geometric arrangement and orientation in relation to their interacting partners define the success, or otherwise, of the amyloid formation reaction. Although not realistic at the molecular level, the model captures some essential features of the system and is therefore useful from a heuristic standpoint. For the case of amyloid formation from an unstructured state, the model suggests that the major determinants of the rate of fibril formation are the length of the sequence separating the critical amino acids promoting amyloid formation and the positional placement of the critical residues within the sequence. Our findings suggest also that the sequence distance between the key interacting amino acid residues may play a role in defining the maximum width of a fibril and that the addition of non-interacting segments of long structure-less polypeptide chain to an amyloidogenic peptide may act to inhibit fibril formation. We discuss these findings with reference to the placement of critical sequence residues within the polypeptide chain, the design of polypeptides with lower amyloid formation propensities and the development of aggregation inhibitors as potential therapeutics for protein depositional disorders.
Collapse
Affiliation(s)
- Damien Hall
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB21EW, UK.
| | | | | |
Collapse
|
23
|
Necula M, Kuret J. Site-specific pseudophosphorylation modulates the rate of tau filament dissociation. FEBS Lett 2005; 579:1453-7. [PMID: 15733856 DOI: 10.1016/j.febslet.2005.01.047] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 01/10/2005] [Accepted: 01/25/2005] [Indexed: 01/22/2023]
Abstract
Hyperphosphorylation of tau is of fundamental importance for neurofibrillary lesion development in Alzheimer's disease, but the mechanisms through which it acts are not clear. Experiments with pseudophosphorylation mutants of full-length tau protein indicate that incorporation of negative charge into specific sites can modulate the aggregation reaction, and that this occurs by altering the critical concentration of assembly. Here, the kinetic origin of this effect was determined using quantitative electron microscopy methods and pseudophosphorylation mutant T212E in a full-length four-repeat tau background. On the basis of disaggregation rates, decreases in critical concentration resulted primarily from decreases in the dissociation rate constant. The results suggest a mechanism through which site-specific posttranslational modifications can modulate filament accumulation at low free intracellular tau concentrations.
Collapse
Affiliation(s)
- Mihaela Necula
- Biophysics Program, The Ohio State University College of Medicine and Public Health, Columbus, OH 43210, USA
| | | |
Collapse
|
24
|
Hall D, Edskes H. Silent Prions Lying in Wait: A Two-hit Model of Prion/Amyloid Formation and Infection. J Mol Biol 2004; 336:775-86. [PMID: 15095987 DOI: 10.1016/j.jmb.2003.12.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2003] [Revised: 11/24/2003] [Accepted: 12/02/2003] [Indexed: 11/28/2022]
Abstract
Diseases such as type 2 diabetes, Alzheimer's and Parkinson's are associated with the formation of amyloid. The transmissible spongiform encephalopathies, such as variant Creutzfeldt-Jakob disease, are believed to result from infectious forms of amyloid proteins termed prions. The ability of amyloid to initiate spontaneously and in the case of prions, to transfer successfully from one host to another, has been hard to fully rationalize. In this paper we use a mathematical model to explore the idea that it might be a combination of the presence of the prion/amyloid form and a change in the state of the host that allows the amyloid/prion to successfully initiate and propagate itself. We raise the intriguing possibility that potentially infectious amyloid may lie dormant in an apparently healthy individual awaiting a change in the state of the host or transmittal to a new more susceptible host. On this basis we make an analogy between prion/amyloid disease development and the two-hit model of cancer progression. We additionally raise the possibility that infectious amyloid strains may be characterized by a size distribution of length or radius.
Collapse
Affiliation(s)
- Damien Hall
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health Bethesda, MD 20892-0830, USA.
| | | |
Collapse
|