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Mateos H, Mallardi A, Camero M, Lanave G, Catella C, Buonavoglia A, De Giglio O, Buonavoglia C, Palazzo G. Mechanism of surfactant interactions with feline coronavirus: A physical chemistry perspective. J Colloid Interface Sci 2024; 662:535-544. [PMID: 38364478 DOI: 10.1016/j.jcis.2024.02.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/01/2024] [Accepted: 02/10/2024] [Indexed: 02/18/2024]
Abstract
HYPOTHESIS Surfactants are inexpensive chemicals with promising applications in virus inactivation, particularly for enveloped viruses. Yet, the detailed mechanisms by which surfactants deactivate coronaviruses remain underexplored. This study delves into the virucidal mechanisms of various surfactants on Feline Coronavirus (FCoV) and their potential applications against more pathogenic coronaviruses. EXPERIMENTS By integrating virucidal activity assays with fluorescence spectroscopy, dynamic light scattering and laser Doppler electrophoresis, alongside liposome permeability experiments, we have analyzed the effects of non-ionic and ionic surfactants on viral activity. FINDINGS The non-ionic surfactant octaethylene glycol monodecyl ether (C10EO8) inactivates the virus by disrupting the lipid envelope, whereas ionic surfactants like Sodium Dodecyl Sulfate and Cetylpyridinium Chloride predominantly affect the spike proteins, with their impact on the viral membrane being hampered by kinetic and thermodynamic constraints. FCoV served as a safe model for studying virucidal activity, offering a faster alternative to traditional virucidal assays. The study demonstrates that physicochemical techniques can expedite the screening of virucidal compounds, contributing to the design of effective disinfectant formulations. Our results not only highlight the critical role of surfactant-virus interactions but also contribute to strategic advancements in public health measures for future pandemic containment and the ongoing challenge of antimicrobial resistance.
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Affiliation(s)
- Helena Mateos
- Department of Chemistry and CSGI (Centre for Colloid and Surface Science), University of Bari "A. Moro", via Orabona 4, 70125 Bari, Italy.
| | - Antonia Mallardi
- Institute for Physical and Chemical Processes, Bari Division, National Council of Research (CNR), c/o Chemistry Department, Via Orabona 4, 70125 Bari, Italy.
| | - Michele Camero
- Department of Veterinary Medicine, University of Bari "A. Moro", Strada Provinciale per Casamassima km. 3, 70010 Valenzano, Bari, Italy.
| | - Gianvito Lanave
- Department of Veterinary Medicine, University of Bari "A. Moro", Strada Provinciale per Casamassima km. 3, 70010 Valenzano, Bari, Italy.
| | - Cristiana Catella
- Department of Veterinary Medicine, University of Bari "A. Moro", Strada Provinciale per Casamassima km. 3, 70010 Valenzano, Bari, Italy.
| | - Alessio Buonavoglia
- Dental School, Department of Biomedical and Neuromotor Sciences, University of Bologna Alma Mater, Italy.
| | - Osvalda De Giglio
- Interdisciplinary Department of Medicine, Hygiene Section, University of Bari "A. Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
| | - Canio Buonavoglia
- Department of Veterinary Medicine, University of Bari "A. Moro", Strada Provinciale per Casamassima km. 3, 70010 Valenzano, Bari, Italy.
| | - Gerardo Palazzo
- Department of Chemistry and CSGI (Centre for Colloid and Surface Science), University of Bari "A. Moro", via Orabona 4, 70125 Bari, Italy.
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2
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Lemaire SD, Tedesco D, Crozet P, Michelet L, Fermani S, Zaffagnini M, Henri J. Crystal Structure of Chloroplastic Thioredoxin f2 from Chlamydomonas reinhardtii Reveals Distinct Surface Properties. Antioxidants (Basel) 2018; 7:E171. [PMID: 30477165 PMCID: PMC6316601 DOI: 10.3390/antiox7120171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/13/2018] [Accepted: 11/20/2018] [Indexed: 12/14/2022] Open
Abstract
Protein disulfide reduction by thioredoxins (TRXs) controls the conformation of enzyme active sites and their multimeric complex formation. TRXs are small oxidoreductases that are broadly conserved in all living organisms. In photosynthetic eukaryotes, TRXs form a large multigenic family, and they have been classified in different types: f, m, x, y, and z types are chloroplastic, while o and h types are located in mitochondria and cytosol. In the model unicellular alga Chlamydomonas reinhardtii, the TRX family contains seven types, with f- and h-types represented by two isozymes. Type-f TRXs interact specifically with targets in the chloroplast, controlling photosynthetic carbon fixation by the Calvin⁻Benson cycle. We solved the crystal structures of TRX f2 and TRX h1 from C. reinhardtii. The systematic comparison of their atomic features revealed a specific conserved electropositive crown around the active site of TRX f, complementary to the electronegative surface of their targets. We postulate that this surface provides specificity to each type of TRX.
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Affiliation(s)
- Stéphane D Lemaire
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226 CNRS Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Daniele Tedesco
- Bio-Pharmaceutical Analysis Section (Bio-PhASe), Department of Pharmacy and Biotechnology, University of Bologna, via Belmeloro 6, 40126 Bologna, Italy.
| | - Pierre Crozet
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226 CNRS Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Laure Michelet
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226 CNRS Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Simona Fermani
- Department of Chemistry "Giacomo Ciamician", University of Bologna, via Selmi 2, 40126 Bologna, Italy.
| | - Mirko Zaffagnini
- Laboratory of Molecular Plant Physiology, Department of Pharmacy and Biotechnology, University of Bologna, via Irnerio 42, 40126 Bologna, Italy.
| | - Julien Henri
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226 CNRS Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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Izutsu KI. Applications of Freezing and Freeze-Drying in Pharmaceutical Formulations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1081:371-383. [DOI: 10.1007/978-981-13-1244-1_20] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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4
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Romero-Romero ML, Risso VA, Martinez-Rodriguez S, Gaucher EA, Ibarra-Molero B, Sanchez-Ruiz JM. Selection for Protein Kinetic Stability Connects Denaturation Temperatures to Organismal Temperatures and Provides Clues to Archaean Life. PLoS One 2016; 11:e0156657. [PMID: 27253436 PMCID: PMC4890807 DOI: 10.1371/journal.pone.0156657] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/17/2016] [Indexed: 01/24/2023] Open
Abstract
The relationship between the denaturation temperatures of proteins (Tm values) and the living temperatures of their host organisms (environmental temperatures: TENV values) is poorly understood. Since different proteins in the same organism may show widely different Tm’s, no simple universal relationship between Tm and TENV should hold, other than Tm≥TENV. Yet, when analyzing a set of homologous proteins from different hosts, Tm’s are oftentimes found to correlate with TENV’s but this correlation is shifted upward on the Tm axis. Supporting this trend, we recently reported Tm’s for resurrected Precambrian thioredoxins that mirror a proposed environmental cooling over long geological time, while remaining a shocking ~50°C above the proposed ancestral ocean temperatures. Here, we show that natural selection for protein kinetic stability (denaturation rate) can produce a Tm↔TENV correlation with a large upward shift in Tm. A model for protein stability evolution suggests a link between the Tm shift and the in vivo lifetime of a protein and, more specifically, allows us to estimate ancestral environmental temperatures from experimental denaturation rates for resurrected Precambrian thioredoxins. The TENV values thus obtained match the proposed ancestral ocean cooling, support comparatively high Archaean temperatures, and are consistent with a recent proposal for the environmental temperature (above 75°C) that hosted the last universal common ancestor. More generally, this work provides a framework for understanding how features of protein stability reflect the environmental temperatures of the host organisms.
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Affiliation(s)
- M. Luisa Romero-Romero
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
| | - Valeria A. Risso
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
| | | | - Eric A. Gaucher
- Georgia Institute of Technology, School of Biology, School of Chemistry and Biochemistry, and Parker H. Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia, 30332, United States of America
| | - Beatriz Ibarra-Molero
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
| | - Jose M. Sanchez-Ruiz
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
- * E-mail:
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5
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Kotchoni SO, Gachomo EW, Slobodenko K, Shain DH. AMP deaminase suppression increases biomass, cold tolerance and oil content in green algae. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Effect of Temperature on Xylanase II from Trichoderma reesei QM 9414: A Calorimetric, Catalytic, and Conformational Study. Enzyme Res 2014; 2014:708676. [PMID: 25276420 PMCID: PMC4170777 DOI: 10.1155/2014/708676] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 11/17/2022] Open
Abstract
The secondary structure of xylanase II from Trichoderma reesei is lost in an apparent irreversible cooperative process as temperature is increased with a midpoint transition of 58.8 ± 0.1°C. The shift of the spectral centre of mass above 50°C is also apparently cooperative with midpoint transition of 56.3 ± 0.2°C, but the existence of two isofluorescent points in the fluorescence emission spectra suggests a non-two-state process. Further corroboration comes from differential scanning calorimetry experiments. At protein concentrations ≤0.56 mg·mL−1 the calorimetric transition is reversible and the data were fitted to a non-two-state model and deconvoluted into six transitions, whereas at concentrations greater than 0.56 mg·mL−1 the calorimetric transition is irreversible with an exothermic contribution to the thermogram. The apparent Tm increased linearly with the scan rate according to first order inactivation kinetics. The effect of additives on the calorimetric transition of xylanase is dependent on their nature. The addition of sorbitol transforms reversible transitions into irreversible transitions while stabilizing the protein as the apparent Tm increases linearly with sorbitol concentration. d-Glucono-1,5-lactone, a noncompetitive inhibitor in xylanase kinetics, and soluble xylan change irreversible processes into reversible processes at high protein concentration.
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7
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Baez D, Raddatz N, Ferreira G, Gonzalez C, Latorre R. Gating of thermally activated channels. CURRENT TOPICS IN MEMBRANES 2014; 74:51-87. [PMID: 25366233 DOI: 10.1016/b978-0-12-800181-3.00003-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A class of ion channels that belongs to the transient receptor potential (TRP) superfamily and is present in specialized neurons that project to the skin has evolved as temperature detectors. These channels are classified into subfamilies, namely canonical (TRPC), melastatin (TRPM), ankyrin (TRPA), and vanilloid (TRPV). Some of these channels are activated by heat (TRPM2/4/5, TRPV1-4), while others by cold (TRPA1, TRPC5, and TRPM8). The general structure of these channels is closely related to that of the voltage-dependent K(+) channels, with their subunits containing six transmembrane segments that form tetramers. Thermal TRP channels are polymodal receptors. That is, they can be activated by temperature, voltage, pH, lipids, and agonists. The high temperature sensitivity in these thermal TRP channels is due to a large enthalpy change (∼100 kcal/mol), which is about five times the enthalpy change in voltage-dependent gating. The characterization of the macroscopic currents and single-channel analysis demonstrated that gating by temperature is complex and best described by branched or allosteric models containing several closed and open states. The identification of molecular determinants of temperature sensitivity in TRPV1, TRPA1, and TRPV3 strongly suggest that thermal sensitivity arises from a specific protein domain.
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Affiliation(s)
- David Baez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Natalia Raddatz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Centre for Plant Biotechnology and Genomics, Universidad Politécnica de Madrid, Pozuelo de Alarcón (Madrid), Spain
| | - Gonzalo Ferreira
- Laboratorio de Canales Iónicos, Departamento de Biofísica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Carlos Gonzalez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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8
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Ramírez-Sarmiento CA, Baez M, Wilson CAM, Babul J, Komives EA, Guixé V. Observation of solvent penetration during cold denaturation of E. coli phosphofructokinase-2. Biophys J 2013; 104:2254-63. [PMID: 23708365 DOI: 10.1016/j.bpj.2013.04.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/07/2013] [Accepted: 04/12/2013] [Indexed: 11/16/2022] Open
Abstract
Phosphofructokinase-2 is a dimeric enzyme that undergoes cold denaturation following a highly cooperative N2 2I mechanism with dimer dissociation and formation of an expanded monomeric intermediate. Here, we use intrinsic fluorescence of a tryptophan located at the dimer interface to show that dimer dissociation occurs slowly, over several hours. We then use hydrogen-deuterium exchange mass spectrometry experiments, performed by taking time points over the cold denaturation process, to measure amide exchange throughout the protein during approach to the cold denatured state. As expected, a peptide corresponding to the dimer interface became more solvent exposed over time at 3°C; unexpectedly, amide exchange increased throughout the protein over time at 3°C. The rate of increase in amide exchange over time at 3°C was the same for each region and equaled the rate of dimer dissociation measured by tryptophan fluorescence, suggesting that dimer dissociation and formation of the cold denatured intermediate occur without appreciable buildup of folded monomer. The observation that throughout the protein amide exchange increases as phosphofructokinase-2 cold denatures provides experimental evidence for theoretical predictions that cold denaturation primarily occurs by solvent penetration into the hydrophobic core of proteins in a sequence-independent manner.
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9
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Analysis of Arabidopsis thioredoxin-h isotypes identifies discrete domains that confer specific structural and functional properties. Biochem J 2013; 456:13-24. [DOI: 10.1042/bj20130618] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this study, we identified specific domains and amino acids responsible for the structural and functional properties of AtTrx-hs (Arabidopsis h-type thioredoxins). Specific domains and amino acids for the chaperone function of AtTrx-hs played a critical role in heat-shock-resistance in vivo.
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10
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Valledor L, Furuhashi T, Hanak AM, Weckwerth W. Systemic cold stress adaptation of Chlamydomonas reinhardtii. Mol Cell Proteomics 2013; 12:2032-47. [PMID: 23564937 PMCID: PMC3734567 DOI: 10.1074/mcp.m112.026765] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/15/2013] [Indexed: 11/06/2022] Open
Abstract
Chlamydomonas reinhardtii is one of the most important model organisms nowadays phylogenetically situated between higher plants and animals (Merchant et al. 2007). Stress adaptation of this unicellular model algae is in the focus because of its relevance to biomass and biofuel production. Here, we have studied cold stress adaptation of C. reinhardtii hitherto not described for this algae whereas intensively studied in higher plants. Toward this goal, high throughput mass spectrometry was employed to integrate proteome, metabolome, physiological and cell-morphological changes during a time-course from 0 to 120 h. These data were complemented with RT-qPCR for target genes involved in central metabolism, signaling, and lipid biosynthesis. Using this approach dynamics in central metabolism were linked to cold-stress dependent sugar and autophagy pathways as well as novel genes in C. reinhardtii such as CKIN1, CKIN2 and a hitherto functionally not annotated protein named CKIN3. Cold stress affected extensively the physiology and the organization of the cell. Gluconeogenesis and starch biosynthesis pathways are activated leading to a pronounced starch and sugar accumulation. Quantitative lipid profiles indicate a sharp decrease in the lipophilic fraction and an increase in polyunsaturated fatty acids suggesting this as a mechanism of maintaining membrane fluidity. The proteome is completely remodeled during cold stress: specific candidates of the ribosome and the spliceosome indicate altered biosynthesis and degradation of proteins important for adaptation to low temperatures. Specific proteasome degradation may be mediated by the observed cold-specific changes in the ubiquitinylation system. Sparse partial least squares regression analysis was applied for protein correlation network analysis using proteins as predictors and Fv/Fm, FW, total lipids, and starch as responses. We applied also Granger causality analysis and revealed correlations between proteins and metabolites otherwise not detectable. Twenty percent of the proteins responsive to cold are uncharacterized proteins. This presents a considerable resource for new discoveries in cold stress biology in alga and plants.
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Affiliation(s)
- Luis Valledor
- ‡From the Department of Molecular Systems Biology, Faculty of Life Sciences, University of Vienna, Austria, Althanstrasse 14, A-1090, Vienna, Austria
| | - Takeshi Furuhashi
- ‡From the Department of Molecular Systems Biology, Faculty of Life Sciences, University of Vienna, Austria, Althanstrasse 14, A-1090, Vienna, Austria
| | - Anne-Mette Hanak
- ‡From the Department of Molecular Systems Biology, Faculty of Life Sciences, University of Vienna, Austria, Althanstrasse 14, A-1090, Vienna, Austria
| | - Wolfram Weckwerth
- ‡From the Department of Molecular Systems Biology, Faculty of Life Sciences, University of Vienna, Austria, Althanstrasse 14, A-1090, Vienna, Austria
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11
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Expanded monomeric intermediate upon cold and heat unfolding of phosphofructokinase-2 from Escherichia coli. Biophys J 2012. [PMID: 23200052 DOI: 10.1016/j.bpj.2012.09.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Folding studies have been focused mainly on small, single-domain proteins or isolated single domains of larger proteins. However, most of the proteins present in biological systems are composed of multiple domains, and to date, the principles that underlie its folding remain elusive. The unfolding of Pfk-2 induced by GdnHCl has been described by highly cooperative three-state equilibrium (N(2)↔2I↔2U). This is characterized by a strong coupling between the subunits' tertiary structure and the integrity of the dimer interface because "I" represents an unstructured and expanded monomeric intermediate. Here we report that cold and heat unfolding of Pfk-2 resembles the N(2)↔2I step of chemically induced unfolding. Moreover, cold unfolding appears to be as cooperative as that induced chemically and even more so than its heat-unfolding counterpart. Because Pfk-2 is a large homodimer of 66 kDa with a complex topology consisting of well-defined domains, these results are somewhat unexpected considering that cold unfolding has been described as a special kind of perturbation that decouples the cooperative unfolding of several proteins.
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12
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Matsuo K, Sakurada Y, Tate SI, Namatame H, Taniguchi M, Gekko K. Secondary-structure analysis of alcohol-denatured proteins by vacuum-ultraviolet circular dichroism spectroscopy. Proteins 2011; 80:281-93. [DOI: 10.1002/prot.23206] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/07/2011] [Accepted: 09/19/2011] [Indexed: 11/07/2022]
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Romero-Romero ML, Inglés-Prieto A, Ibarra-Molero B, Sanchez-Ruiz JM. Highly anomalous energetics of protein cold denaturation linked to folding-unfolding kinetics. PLoS One 2011; 6:e23050. [PMID: 21829584 PMCID: PMC3146537 DOI: 10.1371/journal.pone.0023050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/05/2011] [Indexed: 11/29/2022] Open
Abstract
Despite several careful experimental analyses, it is not yet clear whether protein cold-denaturation is just a “mirror image” of heat denaturation or whether it shows unique structural and energetic features. Here we report that, for a well-characterized small protein, heat denaturation and cold denaturation show dramatically different experimental energetic patterns. Specifically, while heat denaturation is endothermic, the cold transition (studied in the folding direction) occurs with negligible heat effect, in a manner seemingly akin to a gradual, second-order-like transition. We show that this highly anomalous energetics is actually an apparent effect associated to a large folding/unfolding free energy barrier and that it ultimately reflects kinetic stability, a naturally-selected trait in many protein systems. Kinetics thus emerges as an important factor linked to differential features of cold denaturation. We speculate that kinetic stabilization against cold denaturation may play a role in cold adaptation of psychrophilic organisms. Furthermore, we suggest that folding-unfolding kinetics should be taken into account when analyzing in vitro cold-denaturation experiments, in particular those carried out in the absence of destabilizing conditions.
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Affiliation(s)
- M. Luisa Romero-Romero
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Alvaro Inglés-Prieto
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Beatriz Ibarra-Molero
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Jose M. Sanchez-Ruiz
- Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Granada, Granada, Spain
- * E-mail:
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14
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Aguado-Llera D, Martínez-Gómez AI, Prieto J, Marenchino M, Traverso JA, Gómez J, Chueca A, Neira JL. The conformational stability and biophysical properties of the eukaryotic thioredoxins of Pisum sativum are not family-conserved. PLoS One 2011; 6:e17068. [PMID: 21364950 PMCID: PMC3043092 DOI: 10.1371/journal.pone.0017068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 01/12/2011] [Indexed: 12/22/2022] Open
Abstract
Thioredoxins (TRXs) are ubiquitous proteins involved in redox processes. About forty genes encode TRX or TRX-related proteins in plants, grouped in different families according to their subcellular localization. For instance, the h-type TRXs are located in cytoplasm or mitochondria, whereas f-type TRXs have a plastidial origin, although both types of proteins have an eukaryotic origin as opposed to other TRXs. Herein, we study the conformational and the biophysical features of TRXh1, TRXh2 and TRXf from Pisum sativum. The modelled structures of the three proteins show the well-known TRX fold. While sharing similar pH-denaturations features, the chemical and thermal stabilities are different, being PsTRXh1 (Pisum sativum thioredoxin h1) the most stable isoform; moreover, the three proteins follow a three-state denaturation model, during the chemical-denaturations. These differences in the thermal- and chemical-denaturations result from changes, in a broad sense, of the several ASAs (accessible surface areas) of the proteins. Thus, although a strong relationship can be found between the primary amino acid sequence and the structure among TRXs, that between the residue sequence and the conformational stability and biophysical properties is not. We discuss how these differences in the biophysical properties of TRXs determine their unique functions in pea, and we show how residues involved in the biophysical features described (pH-titrations, dimerizations and chemical-denaturations) belong to regions involved in interaction with other proteins. Our results suggest that the sequence demands of protein-protein function are relatively rigid, with different protein-binding pockets (some in common) for each of the three proteins, but the demands of structure and conformational stability per se (as long as there is a maintained core), are less so.
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Affiliation(s)
- David Aguado-Llera
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche (Alicante), Spain
| | - Ana Isabel Martínez-Gómez
- Departamento de Química-Física, Bioquímica y Química Inorgánica, Universidad de Almería, Almería, Spain
| | - Jesús Prieto
- Departamento de Biología Estructural y Biocomputación, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Marco Marenchino
- Departamento de Biología Estructural y Biocomputación, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - José Angel Traverso
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental Zaidin, Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Javier Gómez
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche (Alicante), Spain
| | - Ana Chueca
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental Zaidin, Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - José L. Neira
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche (Alicante), Spain
- Biocomputation and Complex Systems Physics Institute, Zaragoza, Spain
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15
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Gating of transient receptor potential melastatin 8 (TRPM8) channels activated by cold and chemical agonists in planar lipid bilayers. J Neurosci 2010; 30:12526-34. [PMID: 20844147 DOI: 10.1523/jneurosci.3189-10.2010] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The transient receptor potential melastatin 8 (TRPM8) ion channel is a major sensor of environmental cold temperatures. It is activated by cold and chemical agonists, such as menthol and icilin. The activation of these channels both by cold and cooling agents requires the presence of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)]. The mechanism of TRPM8 activation by physical and chemical factors is unknown, and the involvement of cellular signaling pathways has been considered. Here we have characterized the gating mechanism of the rat TRPM8 reconstituted in planar lipid bilayers and its activation by different stimuli. In this system, the influence of cellular signaling pathways can be excluded. We found that TRPM8 activated by cold exhibits steep temperature dependence [temperature coefficient (Q(10)) of ∼40], and the channel openings are accompanied by large changes in entropy and enthalpy, suggesting a substantial conformation change. TRPM8 channel behavior upon menthol and icilin activation was distinguishable, and the effect of icilin depended on the presence of calcium on the intracellular side of the protein. Here we also demonstrate that PI(4,5)P(2) is the prime factor that impacts the gating of TRPM8 and that other phosphoinositides are less efficient in supporting channel activity. Menthol increases the potency of PI(4,5)P(2) to activate the channels and increases binding of phosphoinositides to the full-length channel protein. Our data demonstrate conclusively that TRPM8 is gated by cold and its chemical agonists directly, and that dependence of its gating on PI(4,5)P(2) is a result of direct specific interactions with the lipid.
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Patel MM, Sgourakis NG, Garcia AE, Makhatadze GI. Experimental Test of the Thermodynamic Model of Protein Cooperativity Using Temperature-Induced Unfolding of a Ubq−UIM Fusion Protein. Biochemistry 2010; 49:8455-67. [DOI: 10.1021/bi101163u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mayank M. Patel
- Center for Biotechnology and Interdisciplinary Studies and Department of Biology
| | | | | | - George I. Makhatadze
- Center for Biotechnology and Interdisciplinary Studies and Department of Biology
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Palazzo G, Lopez F, Mallardi A. Effect of detergent concentration on the thermal stability of a membrane protein: The case study of bacterial reaction center solubilized by N,N-dimethyldodecylamine-N-oxide. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:137-46. [DOI: 10.1016/j.bbapap.2009.09.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/17/2009] [Accepted: 09/21/2009] [Indexed: 11/29/2022]
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18
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Davidovic M, Mattea C, Qvist J, Halle B. Protein Cold Denaturation as Seen From the Solvent. J Am Chem Soc 2008; 131:1025-36. [DOI: 10.1021/ja8056419] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Monika Davidovic
- Department of Biophysical Chemistry, Center for Molecular Protein Science, Lund University, SE-22100 Lund, Sweden
| | - Carlos Mattea
- Department of Biophysical Chemistry, Center for Molecular Protein Science, Lund University, SE-22100 Lund, Sweden
| | - Johan Qvist
- Department of Biophysical Chemistry, Center for Molecular Protein Science, Lund University, SE-22100 Lund, Sweden
| | - Bertil Halle
- Department of Biophysical Chemistry, Center for Molecular Protein Science, Lund University, SE-22100 Lund, Sweden
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Matsuo K, Sakurada Y, Yonehara R, Kataoka M, Gekko K. Secondary-structure analysis of denatured proteins by vacuum-ultraviolet circular dichroism spectroscopy. Biophys J 2007; 92:4088-96. [PMID: 17369421 PMCID: PMC1868981 DOI: 10.1529/biophysj.106.103515] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To elucidate the structure of denatured proteins, we measured the vacuum-ultraviolet circular dichroism (VUVCD) spectra from 260 to 172 nm of three proteins (metmyoglobin, staphylococcal nuclease, and thioredoxin) in the native and the acid-, cold-, and heat-denatured states, using a synchrotron-radiation VUVCD spectrophotometer. The circular dichroism spectra of proteins fully unfolded by guanidine hydrochloride (GdnHCl) were also measured down to 197 nm for comparison. These denatured proteins exhibited characteristic VUVCD spectra that reflected a considerable amount of residual secondary structures. The contents of alpha-helices, beta-strands, turns, poly-L-proline type II (PPII), and unordered structures were estimated for each denatured state of the three proteins using the SELCON3 program with Protein Data Bank data and the VUVCD spectra of 31 reference proteins reported in our previous study. Based on these contents, the characteristics of the four types of denaturation were discussed for each protein. In all types of denaturation, a decrease in alpha-helices was accompanied by increases in beta-strands, PPII, and unordered structures. About 20% beta-strands were present even in the proteins fully unfolded by GdnHCl in which beta-sheets should be broken. From these results, we propose that denatured proteins constitute an ensemble of residual alpha-helices and beta-sheets, partly unfolded (or distorted) alpha-helices and beta-strands, PPII, and unordered structures.
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Affiliation(s)
- Koichi Matsuo
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
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Meersman F, Smeller L, Heremans K. Protein stability and dynamics in the pressure–temperature plane. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:346-54. [PMID: 16414316 DOI: 10.1016/j.bbapap.2005.11.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 11/23/2005] [Accepted: 11/28/2005] [Indexed: 10/25/2022]
Abstract
The pressure-temperature stability diagram of proteins and the underlying assumptions of the elliptical shape of the diagram are discussed. Possible extensions, such as aggregation and fibril formation, are considered. An important experimental observation is the extreme pressure stability of the mature fibrils. Molecular origins of the diagram in terms of models of the partial molar volume of a protein focus on cavities and hydration. Changes in thermal expansivity, compressibility and heat capacity in terms of fluctuations of the enthalpy and volume change of the unfolding should also focus on these parameters. It is argued that the study of water-soluble polymers might further our understanding of the stability diagram. Whereas the role of water in protein behaviour is unquestioned, the role of cavities is less clear.
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Affiliation(s)
- Filip Meersman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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21
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Hill JJ, Shalaev EY, Zografi G. Thermodynamic and dynamic factors involved in the stability of native protein structure in amorphous solids in relation to levels of hydration. J Pharm Sci 2005; 94:1636-67. [PMID: 15965985 DOI: 10.1002/jps.20333] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The internal, dynamical fluctuations of protein molecules exhibit many of the features typical of polymeric and bulk small molecule glass forming systems. The response of a protein's internal molecular mobility to temperature changes is similar to that of other amorphous systems, in that different types of motions freeze out at different temperatures, suggesting they exhibit the alpha-beta-modes of motion typical of polymeric glass formers. These modes of motion are attributed to the dynamic regimes that afford proteins the flexibility for function but that also develop into the large-scale collective motions that lead to unfolding. The protein dynamical transition, T(d), which has the same meaning as the T(g) value of other amorphous systems, is attributed to the temperature where protein activity is lost and the unfolding process is inhibited. This review describes how modulation of T(d) by hydration and lyoprotectants can determine the stability of protein molecules that have been processed as bulk, amorphous materials. It also examines the thermodynamic, dynamic, and molecular factors involved in stabilizing folded proteins, and the effects typical pharmaceutical processes can have on native protein structure in going from the solution state to the solid state.
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Affiliation(s)
- John J Hill
- ICOS Corporation, 22021 20th Avenue SE, Bothell, WA 98021, USA.
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Teles RCL, Calderon LDA, Medrano FJ, Barbosa JARG, Guimarães BG, Santoro MM, de Freitas SM. pH dependence thermal stability of a chymotrypsin inhibitor from Schizolobium parahyba seeds. Biophys J 2005; 88:3509-17. [PMID: 15764660 PMCID: PMC1305497 DOI: 10.1529/biophysj.104.045682] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Accepted: 02/04/2005] [Indexed: 11/18/2022] Open
Abstract
The thermal stability of a Schizolobium parahyba chymotrypsin inhibitor (SPCI) as a function of pH has been investigated using fluorescence, circular dichroism, and differential scanning calorimetry (DSC). The thermodynamic parameters derived from all methods are remarkably similar and strongly suggest the high stability of SPCI under a wide range of pH. The transition temperature (T(m)) values ranging from 57 to 85.3 degrees C at acidic, neutral, and alkaline pH are in good agreement with proteins from mesophilic and thermophilic organisms and corroborate previous data regarding the thermal stability of SPCI. All methods gave transitions curves adequately fitted to a two-state model of the unfolding process as judged by the cooperative ratio between the van't Hoff and the calorimetric enthalpy energies close to unity in all of the pH conditions analyzed, except at pH 3.0. Thermodynamic analysis using all these methods reveals that SPCI is thermally a highly stable protein, over the wide range of pH from 3.0 to 8.8, exhibiting high stability in the pH region of 5.0-7.0. The corresponding maximum stabilities, DeltaG(25), were obtained at pH 7.0 with values of 15.4 kcal mol(-1) (combined fluorescence and circular dichroism data), and 15.1 kcal mol(-1) (DSC), considering a DeltaC(p) of 1.72 +/- 0.24 kcal mol(-1) K(-1). The low histidine content ( approximately 1.7%) and the high acidic residue content ( approximately 22.5%) suggests a flat pH dependence of thermal stability in the region 2.0-8.8 and that the decrease in thermal stability at low pH can be due to the differences in pK values of the acidic groups.
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Affiliation(s)
- Rozeni C L Teles
- Universidade de Brasília, Depto Biologia Celular, Laboratório de Biofísica, Brasilia DF, Brazil, 70910-900
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Meersman F, Smeller L, Heremans K. Extending the Pressure-Temperature State Diagram of Myoglobin. Helv Chim Acta 2005. [DOI: 10.1002/hlca.200590037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wasylewski M. Evaluation of riboflavin binding protein domain interaction using differential scanning calorimetry. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1702:137-43. [PMID: 15488765 DOI: 10.1016/j.bbapap.2004.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Revised: 07/01/2004] [Accepted: 07/20/2004] [Indexed: 10/26/2022]
Abstract
Riboflavin binding (or carrier) protein (RfBP) is a monomeric, two-domain protein, originally purified from hens' egg white. RfBP contains nine disulfide bridges; as a result, the protein forms a compact structure and undergoes reversible three-state thermal denaturation. This was demonstrated using a differential scanning calorimetry (DSC) method [Wasylewski M. (2000) J. Prot. Chem. 19(6), 523-528]. It has been shown that the RfBP complex with riboflavin denaturates in a three-state process which may be attributed to sequential unfolding of the RfBP domains. In case of apo RfBP, the ligand binding domain denaturates at a lower temperature than the C-terminal domain. Ligand binding greatly enhances the thermostability of the N-terminal domain, whereas the C-terminal domain thermostability is only slightly affected and, in case of the examined holo RfBPs, the denaturation peaks of both domains merge or cross over. The magnitude of the changes depends on ligand structure. A detailed study of protein concentration effects carried out in this work allowed to estimate not only the thermostability of both domains but also the strength of domain interactions. The DeltaCp, of denaturation was found for C-terminus and N-terminus of RfBP-riboflavin complex to amount to 2.5 and -1.9 kcal mol(-1), respectively. The calculated domain interaction free energy, DeltaGCN, was estimated to be approximately -1580 cal mol(-1) at 67.0 degrees C. This value indicates that the interdomain interaction is of medium strength.
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Affiliation(s)
- Marcin Wasylewski
- Department of Medicinal Chemistry, Institute of Pharmacology, Polish Academy of Sciences ul. Smetna 12 31-343 Kraków, Poland.
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Brauchi S, Orio P, Latorre R. Clues to understanding cold sensation: thermodynamics and electrophysiological analysis of the cold receptor TRPM8. Proc Natl Acad Sci U S A 2004; 101:15494-9. [PMID: 15492228 PMCID: PMC523461 DOI: 10.1073/pnas.0406773101] [Citation(s) in RCA: 268] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The cold and menthol receptor, TRPM8, also designated CMR1, is a member of the transient receptor potential (TRP) family of excitatory ion channels. TRPM8 is a channel activated by cold temperatures, voltage, and menthol. In this study, we characterize the cold- and voltage-induced activation of TRPM8 channel in an attempt to identify the temperature- and voltage-dependent components involved in channel activation. Under equilibrium conditions, decreasing temperature has two effects. (i) It shifts the normalized conductance vs. voltage curves toward the left, along the voltage axis. This effect indicates that the degree of order is higher when the channel is in the open configuration. (ii) It increases the maximum channel open probability, suggesting that temperature affects both voltage-dependent and -independent pathways. In the temperature range between 18 degrees C and 25 degrees C, large changes in enthalpy (DeltaH=-112 kcal/mol) and entropy (DeltaS=-384 cal/mol K) accompany the activation process. The Q10 calculated in the same temperature range is 24. This thermodynamic analysis strongly suggests that the process of opening involves large conformational changes of the channel-forming protein. Therefore, the highly temperature-dependent transition between open and closed configurations is possible because enthalpy and entropy are both large and compensate each other. Our data also demonstrate that temperature and voltage interact allosterically to enhance channel opening.
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26
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Lee DY, Kim KA, Yu YG, Kim KS. Substitution of aspartic acid with glutamic acid increases the unfolding transition temperature of a protein. Biochem Biophys Res Commun 2004; 320:900-6. [PMID: 15240133 DOI: 10.1016/j.bbrc.2004.06.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Indexed: 11/17/2022]
Abstract
Proteins from thermophiles are more stable than those from mesophiles. Several factors have been suggested as causes for this greater stability, but no general rule has been found. The amino acid composition of thermophile proteins indicates that the content of polar amino acids such as Asn, Gln, Ser, and Thr is lower, and that of charged amino acids such as Arg, Glu, and Lys is higher than in mesophile proteins. Among charged amino acids, however, the content of Asp is even lower in thermophile proteins than in mesophile proteins. To investigate the reasons for the lower occurrence of Asp compared to Glu in thermophile proteins, Glu was substituted with Asp in a hyperthermophile protein, MjTRX, and Asp was substituted with Glu in a mesophile protein, ETRX. Each substitution of Glu with Asp decreased the Tm of MjTRX by about 2 degrees C, while each substitution of Asp with Glu increased the Tm of ETRX by about 1.5 degrees C. The change of Tm destabilizes the MjTRX by 0.55 kcal/mol and stabilizes the ETRX by 0.45 kcal/mol in free energy.
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Affiliation(s)
- Duck Yeon Lee
- Biomedical Research Center, Korea Institute of Science and Technology, Cheongyang Box 131, Seoul 130-650, Republic of Korea
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Lemaire SD, Collin V, Keryer E, Quesada A, Miginiac-Maslow M. Characterization of thioredoxin y, a new type of thioredoxin identified in the genome of Chlamydomonas reinhardtii. FEBS Lett 2003; 543:87-92. [PMID: 12753911 DOI: 10.1016/s0014-5793(03)00416-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The sequencing of the Arabidopsis genome revealed a multiplicity of thioredoxins (TRX), ubiquitous protein disulfide oxido-reductases. We have analyzed the TRX family in the genome of the unicellular green alga Chlamydomonas reinhardtii and identified eight different thioredoxins for which we have cloned and sequenced the corresponding cDNAs. One of these TRXs represents a new type that we named TRX y. This most probably chloroplastic TRX is highly conserved in photosynthetic organisms. The biochemical characterization of the recombinant protein shows that it exhibits a thermal stability profile and specificity toward target enzymes completely different from those of TRXs characterized so far.
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Affiliation(s)
- S D Lemaire
- Institut de Biotechnologie des Plantes, UMR 8618 CNRS, Université Paris-Sud, Bâtiment 630, 91405 Cedex, Orsay, France.
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Rouhier N, Gelhaye E, Jacquot JP. Redox control by dithiol-disulfide exchange in plants: II. The cytosolic and mitochondrial systems. Ann N Y Acad Sci 2002; 973:520-8. [PMID: 12485921 DOI: 10.1111/j.1749-6632.2002.tb04693.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This paper describes the existence of two pathways efficient in the reduction of disulfide bridges on selected proteins and mitochondria of photosynthetic organisms. The first is constituted by NADPH, the flavoenzyme NADPH thioredoxin reductase, and thioredoxin; and the second by NADPH, glutathione reductase, glutathione, and glutaredoxin. Molecular details concerning the proteins participating in these redox regulatory cascades are provided, and their molecular targets and functions are described.
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Affiliation(s)
- Nicolas Rouhier
- Unité Mixte de Recherches 1136 INRA UHP (Interaction Arbres Microorganismes), Université Henri Poincaré BP 239, 54506 Vandoeuvre Cedex, France.
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Chapeaurouge A, Johansson JS, Ferreira ST. Folding of a de novo designed native-like four-helix bundle protein. J Biol Chem 2002; 277:16478-83. [PMID: 11832477 DOI: 10.1074/jbc.m105232200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The folding of a model native-like dimeric four-helix bundle protein, (alpha(2))(2), was investigated using guanidine hydrochloride, hydrostatic pressure, and low temperature. Unfolding by guanidine hydrochloride followed by circular dichroism and intrinsic fluorescence spectroscopy revealed a highly cooperative transition between the native-like and unfolded states, with free energy of unfolding determined from CD data, DeltaG(unf) = 14.3 +/- 0.8 kcal/mol. However, CD and intrinsic fluorescence data were not superimposable, indicating the presence of an intermediate state during the folding transition. To stabilize the folding intermediate, we used hydrostatic pressure and low temperature. In both cases, dissociation of the dimeric native-like (alpha(2))(2) into folded monomers (alpha(2)) was observed. van't Hoff analysis of the low temperature experiments, assuming a two-state dimer 171-monomer transition, yielded a free energy of dissociation of (alpha(2))(2) of DeltaG(diss) = 11.4 +/- 0.4 kcal/mol, in good agreement with the free energy determined from pressure dissociation experiments (DeltaG(diss) = 10.5 +/- 0.1 kcal/mol). Binding of the hydrophobic fluorescent probe 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) to the pressure- and cold-dissociated states of (alpha(2))(2) indicated the existence of molten-globule monomers. In conclusion, we demonstrate that the folding pathway of (alpha(2))(2) can be described by a three-state transition including a monomeric molten globule-like state.
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Affiliation(s)
- Alex Chapeaurouge
- Departamento de Bioquimica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil.
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Meersman F, Smeller L, Heremans K. Comparative Fourier transform infrared spectroscopy study of cold-, pressure-, and heat-induced unfolding and aggregation of myoglobin. Biophys J 2002; 82:2635-44. [PMID: 11964250 PMCID: PMC1302052 DOI: 10.1016/s0006-3495(02)75605-1] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied the cold unfolding of myoglobin with Fourier transform infrared spectroscopy and compared it with pressure and heat unfolding. Because protein aggregation is a phenomenon with medical as well as biotechnological implications, we were interested in both the structural changes as well as the aggregation behavior of the respective unfolded states. The cold- and pressure-induced unfolding both yield a partially unfolded state characterized by a persistent amount of secondary structure, in which a stable core of G and H helices is preserved. In this respect the cold- and pressure-unfolded states show a resemblance with an early folding intermediate of myoglobin. In contrast, the heat unfolding results in the formation of the infrared bands typical of intermolecular antiparallel beta-sheet aggregation. This implies a transformation of alpha-helix into intermolecular beta-sheet. H/2H-exchange data suggest that the helices are first unfolded and then form intermolecular beta-sheets. The pressure and cold unfolded states do not give rise to the intermolecular aggregation bands that are typical for the infrared spectra of many heat-unfolded proteins. This suggests that the pathways of the cold and pressure unfolding are substantially different from that of the heat unfolding. After return to ambient conditions the cold- or pressure-treated proteins adopt a partially refolded conformation. This aggregates at a lower temperature (32 degrees C) than the native state (74 degrees C).
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Affiliation(s)
- Filip Meersman
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
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