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Li KY, Zhang XR, Huang GQ, Teng J, Guo LP, Li XD, Xiao JX. Complexation between ovalbumin and gum Arabic in high total biopolymer concentrations and the emulsifying ability of the complexes. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128624] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Cai J, Sweeney AM. The Proof Is in the Pidan: Generalizing Proteins as Patchy Particles. ACS CENTRAL SCIENCE 2018; 4:840-853. [PMID: 30062112 PMCID: PMC6062823 DOI: 10.1021/acscentsci.8b00187] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Indexed: 05/07/2023]
Abstract
The Chinese century egg, or pidan, is a traditional preparation of duck eggs that can be stored for months at room temperature without degradation. Raw eggs are soaked in a strong alkaline and salt solution, and the albumin gradually forms a stable, transparent gel. Here, we show that pidan gels belong to the class of materials formed from "patchy particles". We found that the β-sheet structure of ovalbumin, the major protein constituent of egg white, is preserved during gelation, while α-helical regions undergo a degree of unfolding into unstructured random coils that may form attractive patches. Upon dilution in additional strong base, the phase behavior of pidan gels is consistent with patchy-particle thermodynamics. This protein gel is also physically and structurally similar to the protein gels that form the squid lens. Both systems exhibit patchy thermodynamics, and the constituent proteins share physical features including a structured, charged core, and polar, unstructured "arms" that form attractive patches. Our work provides a path toward rational design of proteins for precisely structured, volume-spanning materials.
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Affiliation(s)
- Jing Cai
- Department of Physics and
Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Alison M. Sweeney
- Department of Physics and
Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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3
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Kalapothakis JMD, Morris RJ, Szavits-Nossan J, Eden K, Covill S, Tabor S, Gillam J, Barran PE, Allen RJ, MacPhee CE. A kinetic study of ovalbumin fibril formation: the importance of fragmentation and end-joining. Biophys J 2015; 108:2300-11. [PMID: 25954887 PMCID: PMC4423071 DOI: 10.1016/j.bpj.2015.03.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 03/06/2015] [Accepted: 03/12/2015] [Indexed: 11/18/2022] Open
Abstract
The ability to control the morphologies of biomolecular aggregates is a central objective in the study of self-assembly processes. The development of predictive models offers the surest route for gaining such control. Under the right conditions, proteins will self-assemble into fibers that may rearrange themselves even further to form diverse structures, including the formation of closed loops. In this study, chicken egg white ovalbumin is used as a model for the study of fibril loops. By monitoring the kinetics of self-assembly, we demonstrate that loop formation is a consequence of end-to-end association between protein fibrils. A model of fibril formation kinetics, including end-joining, is developed and solved, showing that end-joining has a distinct effect on the growth of fibrillar mass density (which can be measured experimentally), establishing a link between self-assembly kinetics and the underlying growth mechanism. These results will enable experimentalists to infer fibrillar morphologies from an appropriate analysis of self-assembly kinetic data.
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Affiliation(s)
- Jason M D Kalapothakis
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK; School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Ryan J Morris
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | | | - Kym Eden
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Sam Covill
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Sean Tabor
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Jay Gillam
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Perdita E Barran
- School of Chemistry, The University of Manchester, Manchester, UK
| | - Rosalind J Allen
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Cait E MacPhee
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
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Lara C, Gourdin-Bertin S, Adamcik J, Bolisetty S, Mezzenga R. Self-Assembly of Ovalbumin into Amyloid and Non-Amyloid Fibrils. Biomacromolecules 2012; 13:4213-21. [DOI: 10.1021/bm301481v] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cecile Lara
- Food and Soft Material
Science, Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 9, LFO E 23,
8092 Zürich, Switzerland
| | - Simon Gourdin-Bertin
- Food and Soft Material
Science, Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 9, LFO E 23,
8092 Zürich, Switzerland
| | - Jozef Adamcik
- Food and Soft Material
Science, Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 9, LFO E 23,
8092 Zürich, Switzerland
| | - Sreenath Bolisetty
- Food and Soft Material
Science, Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 9, LFO E 23,
8092 Zürich, Switzerland
| | - Raffaele Mezzenga
- Food and Soft Material
Science, Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 9, LFO E 23,
8092 Zürich, Switzerland
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Marion JD, Van DN, Bell JE, Bell JK. Measuring the effect of ligand binding on the interface stability of multimeric proteins using dynamic light scattering. Anal Biochem 2010; 407:278-80. [PMID: 20732291 DOI: 10.1016/j.ab.2010.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/17/2010] [Accepted: 08/18/2010] [Indexed: 11/28/2022]
Abstract
We have demonstrated that an approach using guanidine hydrochloride at low concentrations to progressively disrupt protein-protein interactions can be quantitated using dynamic light scattering. This approach is sensitive enough to detect ligand-induced changes of subunit-subunit interactions for homo-hexameric glutamate dehydrogenase, allowing ΔΔG of reversible subunit dissociation to be calculated. The use of dynamic light scattering makes this approach generally applicable to soluble proteins to monitor the relative strength of protein-protein interactions with a particular emphasis on assessing the impact of ligand binding on such interfaces.
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Affiliation(s)
- James D Marion
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298, USA
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Cañamares MV, Sevilla P, Sanchez-Cortes S, Garcia-Ramos JV. Surface-enhanced Raman scattering study of the interaction of red dye alizarin with ovalbumin. Biopolymers 2006; 82:405-9. [PMID: 16421915 DOI: 10.1002/bip.20450] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Surface-enhanced Raman spectroscopy and UV-vis absorption spectroscopy were employed to study the interaction between the red dye alizarin and ovalbumin (OA), to check the effect of binding media usually employed when applying this pigment in painting practices based on egg tempera. The protein/alizarin interaction is rather weak and takes place through the alizarin neutral form, which interacts with exposed hydrophobic moieties of OA. This effect is of great interest from an artistic point of view because the dye color can be modified. Furthermore, the interaction with alizarin could induce a change in the protein structure, leading to a denaturation and subsequent aggregation.
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Affiliation(s)
- M V Cañamares
- Instituto de Estructura de la Materia CSIC, Serrano 121, 28006 Madrid, Spain
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Tahtaoui C, Guillier F, Klotz P, Galzi JL, Hibert M, Ilien B. On the Use of Nonfluorescent Dye Labeled Ligands in FRET-Based Receptor Binding Studies. J Med Chem 2005; 48:7847-59. [PMID: 16302823 DOI: 10.1021/jm050459+] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The efficiency of fluorescence resonance energy transfer (FRET) is dependent upon donor-acceptor proximity and spectral overlap, whether the acceptor partner is fluorescent or not. We report here on the design, synthesis, and characterization of two novel pirenzepine derivatives that were coupled to patent blue VF and pinacyanol dyes. These nonfluorescent compounds, when added to cells stably expressing enhanced green fluorescent protein (EGFP)-fused muscarinic M1 receptors, promote EGFP fluorescence extinction in a time-, concentration-, and atropine-dependent manner. They display nanomolar affinity for the muscarinic receptor, determined using either FRET or classical radioligand binding conditions. We provide evidence that these compounds behave as potent acceptors of energy from excited EGFP with quenching efficiencies comparable to those of analogous fluorescent bodipy or rhodamine red pirenzepine derivatives. The advantages they offer over fluorescent ligands are illustrated and discussed in terms of reliability, sensitivity, and wider applicability of FRET-based receptor binding assays.
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Affiliation(s)
- Chouaib Tahtaoui
- Laboratoire de Pharmacochimie de la Communication Cellulaire, Faculté de Pharmacie, UMR CNRS/ULP 7081, 74 route du Rhin, BP 24, 67401 Illkirch, France
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Sabaté R, Gallardo M, Estelrich J. Temperature dependence of the nucleation constant rate in β amyloid fibrillogenesis. Int J Biol Macromol 2005; 35:9-13. [PMID: 15769509 DOI: 10.1016/j.ijbiomac.2004.11.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Beta-amyloid peptide (A beta), in fibrillar form, is the primary constituent of senile plaques, a defining feature of Alzheimer's disease (AD). In solution assays, fibrils form with a lag time, interpreted as a nucleation/condensation-dependent process. The kinetics of fibrillogenesis is controlled by two key parameters: nucleation and elongation rate constants. We report here the study of the temperature dependence of the nucleation rate constant on an A beta monomer concentration of 18.4 microM at pH 7.4 and at temperatures ranging from 302 to 318 K. We found that the nucleation constant varied as in the Arrhenius law, giving an activation energy of 311.2 kJ mol(-1). The corresponding values of enthalpy of activation (deltaH*), entropy of activation (deltaS*) and Gibbs energy of activation (deltaG*) were evaluated by Eyring's equation of absolute reaction rate. A Gibbs energy of activation of approximately 110 kJ mol(-1) was obtained.
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Affiliation(s)
- Raimon Sabaté
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Avda. Joan XXIII s/n 08028-Barcelona, Catalonia, Spain
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Sabaté R, Estelrich J. Pinacyanol as effective probe of fibrillar β-amyloid peptide: Comparative study with Congo Red. Biopolymers 2003; 72:455-63. [PMID: 14587068 DOI: 10.1002/bip.10485] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The binding of pinacyanol (PIN), a cationic cyanine dye, to beta-amyloid fibrils (Abeta), which are associated with Alzheimer disease, was quantified by absorption spectrophotometry to measure the concentration of PIN bound to Abeta as a function of the Abeta concentration or by means of the separation of free PIN from bound PIN by centrifugation and subsequent analysis of the supernatant by visible-absorption spectrophotometry. Both methods gave equivalent results. The stoichiometry of PIN binding to Abeta was 1, and the curve representing the concentration effect of Abeta on the concentration of a dye-Abeta complex showed a biphasic curve instead of the hyperbolic curve that is characteristic of weak ligand-macromolecule interactions [e.g., as shown by Congo Red (CR)]). This and the fact that a Scatchard plot could not be fitted to the experimental data suggested that PIN binds tightly to Abeta. A comparison to the interaction of CR with Abeta led us to conclude that PIN is more sensitive than CR.
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Affiliation(s)
- Raimon Sabaté
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, E 08028 Barcelona, Catalonia, Spain
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Sabaté R, Estelrich J. Disaggregating effects of ethanol at low concentration on beta-poly-L-lysines. Int J Biol Macromol 2003; 32:10-6. [PMID: 12719126 DOI: 10.1016/s0141-8130(03)00019-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein aggregation is involved in a number of disorders, such as Alzheimer's disease, cystic fibrosis, and prion diseases. Such aggregates are formed by peptides in beta-conformation. The study of the processes of aggregation or its inhibition makes it necessary for the peptide to remain in a monomeric state at the beginning of aggregation assays. Using three poly-L-lysine as a model of beta-peptide, we measured the spectral changes occurring in the visible spectrum of Congo Red (CR), a diazo dye, in two solvent media, namely, an aqueous solution of ethanol 10% (v/v), and an aqueous solution of dimethyl sulfoxide (DMSO) 5% (v/v). Aggregation constants show that the presence of ethanol at low concentration produces a disaggregating effect, regardless of the degree of polymerisation of the peptide. This effect is considered to be due to the direct binding of ethanol molecules to the peptide. This binding undergoes an enhancement of the electrostatic repulsion among charged lysine chains.
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Affiliation(s)
- Raimon Sabaté
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona. Avda. Joan XXIII s/n, Catalonia, Spain
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