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Ivanov IT, Paarvanova BK. Radiofrequency dielectric spectroscopy study: Effects of pH, hydrogen bond donors and acceptors on the attachment of spectrin skeleton to the lipid membrane of erythrocytes. Bioelectromagnetics 2024; 45:58-69. [PMID: 38013630 DOI: 10.1002/bem.22491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/07/2023] [Accepted: 11/02/2023] [Indexed: 11/29/2023]
Abstract
Band 3 protein and glycophorin C are the two major integral proteins of the lipid membrane of human red blood cells (RBCs). They are attached from below to a network of elastic filamentous spectrin, the third major RBC membrane protein. The binding properties of the attachments to spectrin affect the shape and deformability of RBCs. We addressed band 3 and glycophorin C attachments to spectrin by measuring the strength of two recently discovered radiofrequency dielectric relaxations, βsp (1.4 MHz) and γ1sp (9 MHz), that are observable as changes in the complex admittance of RBCs in medium. In medium at pH 5.2, and also in media with protic substances (formamide, methylformamide, or urea), the βsp relaxation became inhibited that is attributable to detachment of glycophorin C from spectrin. In medium at pH 9.2, we observed inhibition of γ1sp relaxation attributable to detachment of band 3 from spectrin, as also was seen in media with aprotic substances difluoropyridine, dimethylsolfoxide, dimethylformamide, acetone, sodium tetrakis(4-fluorophenyl)borate), chlorpromazine, thioridazine and trifluopiperazine. The viscogenic cosolvents (glycerol, ethylene glycol, or i-erythritol) inhibited both the βsp and γ1sp relaxations and significantly lowered their characteristic frequencies. Our observations indicate that the glycophorin C attachment to spectrin has nucleophilic centers whose saturation disconnects this attachment and inhibits the βsp relaxation, whereas at band 3-spectrin attachment site, it is the saturation of electrophilic centers that weakens this attachment and inhibits the γ1sp relaxation.
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Affiliation(s)
- Ivan T Ivanov
- Department of Physics, Biophysics, Roentgenology and Radiology, Medical Faculty, Thracian University, Stara Zagora, Bulgaria
| | - Boyana K Paarvanova
- Department of Physics, Biophysics, Roentgenology and Radiology, Medical Faculty, Thracian University, Stara Zagora, Bulgaria
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2
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Antosiewicz JM. On the possibility of the existence of orienting hydrodynamic steering effects in the kinetics of receptor-ligand association. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:559-568. [PMID: 37173574 PMCID: PMC10618320 DOI: 10.1007/s00249-023-01653-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/10/2023] [Accepted: 04/11/2023] [Indexed: 05/15/2023]
Abstract
In the vast majority of biologically relevant cases of receptor-ligand complex formation, the binding site of the receptor is a small part of its surface, and moreover, formation of a biologically active complex often requires a specific orientation of the ligand relative to the binding site. Before the formation of the initial form of the complex, only long-range, electrostatic and hydrodynamic interactions can act between the ligand approaching the binding site and the receptor. In this context, the question arises whether as a result of these interactions, there is a pre-orientation of the ligand towards the binding site, which to some extent would accelerate the formation of the complex. The role of electrostatic interactions in the orientation of the ligand relative to the binding site of the receptor is well documented. The analogous role of hydrodynamic interactions, although assessed as very significant by Brune and Kim (PNAS 91, 2930-2934, (1994)), is still debatable. In this article, I present the current state of knowledge on this subject and consider the possibilities of demonstrating the orienting effect of hydrodynamic interactions in the processes of receptor-ligand association, in an experimental way supported by computer simulations.
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Affiliation(s)
- Jan M Antosiewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
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3
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Wang Y, He H, Liu L, Gao C, Xu S, Zhao P, Xia Q. Inactivation and unfolding of protein tyrosine phosphatase from Thermus thermophilus HB27 during urea and guanidine hydrochloride denaturation. PLoS One 2014; 9:e107932. [PMID: 25255086 PMCID: PMC4177882 DOI: 10.1371/journal.pone.0107932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/18/2014] [Indexed: 11/19/2022] Open
Abstract
The effects of urea and guanidine hydrochloride (GdnHCl) on the activity, conformation and unfolding process of protein tyrosine phosphatase (PTPase), a thermostable low molecular weight protein from Thermus thermophilus HB27, have been studied. Enzymatic activity assays showed both urea and GdnHCl resulted in the inactivation of PTPase in a concentration and time-dependent manner. Inactivation kinetics analysis suggested that the inactivation of PTPase induced by urea and GdnHCl were both monophasic and reversible processes, and the effects of urea and GdnHCl on PTPase were similar to that of mixed-type reversible inhibitors. Far-ultraviolet (UV) circular dichroism (CD), Tryptophan and 1-anilinonaphthalene -8-sulfonic acid (ANS) fluorescence spectral analyses indicated the existence of a partially active and an inactive molten globule-like intermediate during the unfolding processes induced by urea and GdnHCl, respectively. Based on the sequence alignment and the homolog Tt1001 protein structure, we discussed the possible conformational transitions of PTPase induced by urea and GdnHCl and compared the conformations of these unfolding intermediates with the transient states in bovine PTPase and its complex structures in detail. Our results may be able to provide some valuable clues to reveal the relationship between the structure and enzymatic activity, and the unfolding pathway and mechanism of PTPase.
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Affiliation(s)
- Yejing Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
- College of Biotechnology, Southwest University, Beibei, Chongqing, China
| | - Huawei He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
- College of Biotechnology, Southwest University, Beibei, Chongqing, China
- * E-mail: (QX); (HH)
| | - Lina Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
| | - Chunyan Gao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
| | - Shui Xu
- College of Biotechnology, Southwest University, Beibei, Chongqing, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing, China
- * E-mail: (QX); (HH)
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Cametti C, Marchetti S, Gambi C, Onori G. Dielectric Relaxation Spectroscopy of Lysozyme Aqueous Solutions: Analysis of the δ-Dispersion and the Contribution of the Hydration Water. J Phys Chem B 2011; 115:7144-53. [DOI: 10.1021/jp2019389] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Cametti
- Department of Physics and INFM CRS-SOFT, “La Sapienza” University of Rome, Piazzale A. Moro 5, I-00185, Rome, Italy
| | - S. Marchetti
- Department of Physics, University of Florence and CNISM, Via G. Sansone 1, 50019 Sesto Fiorentino, Florence, Italy
| | - C.M.C. Gambi
- Department of Physics, University of Florence and CNISM, Via G. Sansone 1, 50019 Sesto Fiorentino, Florence, Italy
| | - G. Onori
- Department of Physics and INFM CRS-SOFT, University of Perugia, Via G. Pascoli, Perugia, Italy
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Mellor BL, Cruz Cortés E, Busath DD, Mazzeo BA. Method for Estimating the Internal Permittivity of Proteins Using Dielectric Spectroscopy. J Phys Chem B 2011; 115:2205-13. [DOI: 10.1021/jp1111873] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brett L. Mellor
- Department of Electrical and Computer Engineering and ‡Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, United States
| | - Efrén Cruz Cortés
- Department of Electrical and Computer Engineering and ‡Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, United States
| | - David D. Busath
- Department of Electrical and Computer Engineering and ‡Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, United States
| | - Brian A. Mazzeo
- Department of Electrical and Computer Engineering and ‡Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, United States
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A comparison of the activation energy of viscous flow for hen egg-white lysozyme obtained on the basis of different models of viscosity for glass-forming liquids. ACTA ACUST UNITED AC 2011. [DOI: 10.2478/v10214-011-0001-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A comparison of the activation energy of viscous flow for hen egg-white lysozyme obtained on the basis of different models of viscosity for glass-forming liquids
The paper presents the results of viscosity determinations on aqueous solutions of hen egg-white lysozyme at a wide range of concentrations and at temperatures ranging from 5°C to 55°C. On the basis of these measurements and different models of viscosity for glass-forming liquids, the activation energy of viscous flow for solutions and the studied protein, at different temperatures, was calculated. The analysis of the results obtained shows that the activation energy monotonically decreases with increasing temperature both for solutions and the studied protein. The numerical values of the activation energy for lysozyme, calculated on the basis of discussed models, are very similar in the range of temperatures from 5°C to 35°C.
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Interactions between single-walled carbon nanotubes and lysozyme. J Colloid Interface Sci 2010; 355:342-7. [PMID: 21215413 DOI: 10.1016/j.jcis.2010.12.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 12/02/2010] [Accepted: 12/08/2010] [Indexed: 11/20/2022]
Abstract
Dispersions of single-walled and non-associated carbon nanotubes in aqueous lysozyme solution were investigated by analyzing the stabilizing effect of both protein concentration and pH. It was inferred that the medium pH, which significantly modifies the protein net charge and (presumably) conformation, modulates the mutual interactions with carbon nanotubes. At fixed pH, in addition, the formation of protein/nanotube complexes scales with increasing lysozyme concentration. Electrophoretic mobility, dielectric relaxation and circular dichroism were used to determine the above features. According to circular dichroism, lysozyme adsorbed onto nanotubes could essentially retain its native conformation, but the significant amount of free protein does not allow drawing definitive conclusions on this regard. The state of charge and charge distribution around nanotubes was inferred by combining electrophoretic mobility and dielectric relaxation methods. The former gives information on changes in the surface charge density of the complexes, the latter on modifications in the electrical double layer thickness around them. Such results are complementary each other and univocally indicate that some LYS molecules take part to binding. Above a critical protein/nanotube mass ratio, depletion phenomena were observed. They counteract the stabilization mechanism, with subsequent nanotube/nanotube aggregation and phase separation. Protein-based depletion phenomena are similar to formerly reported effects, observed in aqueous surfactant systems containing carbon nanotubes.
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Mazzeo BA, Chandra S, Mellor BL, Arellano J. Temperature-stable parallel-plate dielectric cell for broadband liquid impedance measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:125103. [PMID: 21198047 DOI: 10.1063/1.3509388] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A liquid impedance cell for broadband impedance measurements up to 110 MHz is presented. The design incorporates temperature control and minimizes parasitic capacitance and inductance. The cell is simple to fabricate and uses chemically resistant materials, stainless steel, and Teflon. This dielectric cell can be used in a variety of liquid measurements, particularly those related to impedance measurements of biological objects in solution. Temperature control is illustrated in measurements of the permittivity of deionized water from 5 to 55 °C. Numerical fitting procedures employed on the relaxation curves indicate good agreement with previous studies on beta-lactoglobulin and hen lysozyme. Titration capability is demonstrated through dielectric titration of hen lysozyme and beta-lactoglobulin.
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Affiliation(s)
- Brian A Mazzeo
- Department of Electrical and Computer Engineering, Brigham Young University, Clyde Building, Provo, Utah 84602, USA.
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Letizia C, Andreozzi P, Scipioni A, La Mesa C, Bonincontro A, Spigone E. Protein binding onto surfactant-based synthetic vesicles. J Phys Chem B 2007; 111:898-908. [PMID: 17249834 DOI: 10.1021/jp0646067] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synthetic vesicles were prepared by mixing anionic and cationic surfactants, aqueous sodium dodecylsulfate with didodecyltrimethylammonium or cetyltrimethylammonium bromide. The overall surfactant content and the (anionic/cationic) mole ratios allow one to obtain negatively charged vesicles. In the phase diagram, the vesicular region is located between a solution phase, a lamellar liquid crystalline dispersion, and a precipitate area. Characterization of the vesicles was performed by electrophoretic mobility, NMR, TEM, and DLS and we determined their uni-lamellar character, size, stability, and charge density. Negatively charged vesicular dispersions, made of sodium dodecylsulfate/didodecyltrimethylammonium bromide or sodium dodecylsulfate/cetyltrimethylammonium bromide, were mixed with lysozyme, to form lipoplexes. Depending on the protein/vesicle charge ratio, binding, surface saturation, and lipoplexes flocculation, or precipitation, occurs. The free protein in excess remains in solution, after binding saturation. The systems were investigated by thermodynamic (surface tension and solution calorimetry), DLS, CD, TEM, 1H NMR, transport properties, electrophoretic mobility, and dielectric relaxation. The latter two methods give information on the vesicle charge neutralization by adsorbed protein. Binding is concomitant to modifications in the double layer thickness of vesicles and in the surface charge density of the resulting lipoplexes. This is also confirmed by developing the electrophoretic mobility results in terms of a Langmuir-like adsorption isotherm. Charges in excess with respect to the amount required to neutralize the vesicle surface promote lipoplexes clustering and/or flocculation. Protein-vesicle interactions were observed by DLS, indicating changes in particle size (and in their distribution functions) upon addition of LYSO. According to CD, the bound protein retains its native conformation, at least in the SDS/CTAB vesicular system. In fact, changes in the alpha-helix and beta-sheet conformations are moderate, if any. Calorimetric methods indicate that the maximum heat effect for LYSO binding occurs at charge neutralization. They also indicate that enthalpic are by far the dominant contributions to the system stability. Accordingly, energy effects associated with charge neutralization and double-layer contributions are much higher than counterion exchange and dehydration terms.
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Affiliation(s)
- Caterina Letizia
- Department of Chemistry, SOFT-INFM-CNR Research Centre, La Sapienza University, P. le A. Moro 5, I-00185 Rome, Italy
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Bonincontro A, Spigone E, Ruiz Peña M, Letizia C, La Mesa C. Lysozyme binding onto cat-anionic vesicles. J Colloid Interface Sci 2006; 304:342-7. [PMID: 17034808 DOI: 10.1016/j.jcis.2006.09.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Revised: 09/12/2006] [Accepted: 09/12/2006] [Indexed: 11/15/2022]
Abstract
Mixing aqueous sodium dodecylsulfate with cetyltrimethylammonium bromide solutions in mole ratios close to (1.7/1.0) allows the formation of cat-anionic vesicles with an excess of negative charges on the outer surface. The vesicular dispersions are mixed with lysozyme, and interact electrostatically with the positive charges on the protein, forming lipo-plexes. Dielectric relaxation, zeta-potential, and light scattering indicate the occurrence of interactions between vesicles and the protein. According to CD, the vesicle-adsorbed protein retains its native conformation. Binding and surface saturation, inferred by dielectric relaxation and zeta-potential, fulfil a charge neutralisation stoichiometry. Adsorbed lysozyme promotes the vesicle clustering and is concomitant with the lipo-plexes flocculation. Above the charge neutralisation threshold, lysozyme in excess remains dispersed in molecular form. Attempts were made to determine in what conditions protein release from the vesicles occurs. Accordingly, the full neutralisation of sodium dodecylsulfate in excess by cetyltrimethylammonium bromide ensures the lipo-plexes break-up, the precipitation of the mixed surfactants and the protein release in native form.
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Affiliation(s)
- A Bonincontro
- CNISM-Department of Physics, University of Rome La Sapienza, P. le A. Moro 5, I-00185 Roma, Italy
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Mijović J, Bian Y, Gross RA, Chen B. Dynamics of Proteins in Hydrated State and in Solution As Studied by Dielectric Relaxation Spectroscopy. Macromolecules 2005. [DOI: 10.1021/ma051854c] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jovan Mijović
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Yu Bian
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Richard A. Gross
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Bo Chen
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
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12
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Investigation by dielectric spectroscopy of domain motions in lysozyme: effect of solvent and binding of inhibitors. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.09.065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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