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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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Ivanov IT, Paarvanova BK. Role of Plasma Membrane at Dielectric Relaxations and Intermembrane Interaction in Human Erythrocytes. MEMBRANES 2023; 13:658. [PMID: 37505024 PMCID: PMC10386205 DOI: 10.3390/membranes13070658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/29/2023]
Abstract
Dielectric relaxations at 1.4 MHz (βsp) and 9 MHz (γ1sp) on the erythrocyte spectrin network were studied by dielectric spectroscopy using dense suspensions of erythrocytes and erythrocyte ghost membranes, subjected to extraction with up to 0.2% volume Triton-X-100. The step-wise extraction of up to 60% of membrane lipids preserved γ1sp and gradually removed βsp-relaxation. On increasing the concentration up to 100 mM of NaCl at either side of erythrocyte plasma membranes, the βsp-relaxation was linearly enhanced, while the strength of γ1sp-relaxation remained unchanged. In media with NaCl between 100 and 150 mM βsp-relaxation became slightly inhibited, while γ1sp-relaxation almost disappeared, possibly due to the decreased electrostatic repulsion allowing erythrocytes to come into closer contact. When these media contained, at concentrations 10-30 mg/mL dextran (MW 7 kDa), polyethylene glycol or polyvinylpyrrolidone (40 kDa), or albumin or homologous plasma with equivalent concentration of albumin, the γ1sp-relaxation was about tenfold enhanced, while βsp-relaxation was strengthened or preserved. The results suggest the Maxwell-Vagner accumulation of ions on the lipid bilayer as an energy source for βsp-relaxation. While βsp-relaxation appears sensitive to erythrocyte membrane deformability, γ1sp-relaxation could be a sensitive marker for the inter-membrane interactions between erythrocytes.
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Affiliation(s)
- Ivan T Ivanov
- Department of Physics, Biophysics, Roentgenology and Radiology, Medical Faculty, Thracian University, 6000 Stara Zagora, Bulgaria
| | - Boyana K Paarvanova
- Department of Physics, Biophysics, Roentgenology and Radiology, Medical Faculty, Thracian University, 6000 Stara Zagora, Bulgaria
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Kayal C, Tamayo-Elizalde M, Adam C, Ye H, Jerusalem A. Voltage-Driven Alterations to Neuron Viscoelasticity. Bioelectricity 2022. [DOI: 10.1089/bioe.2021.0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Celine Kayal
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Miren Tamayo-Elizalde
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Casey Adam
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Hua Ye
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Antoine Jerusalem
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
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Pal S, Bose D, Chakrabarti A, Chattopadhyay A. Comparative Analysis of Tryptophan Dynamics in Spectrin and Its Constituent Domains: Insights from Fluorescence. J Phys Chem B 2021; 126:1045-1053. [PMID: 34845910 DOI: 10.1021/acs.jpcb.1c08600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spectrin is a cytoskeletal protein ubiquitous in metazoan cells that acts as a liaison between the plasma membrane and the cellular interior and imparts mechanical stability to the plasma membrane. Spectrin is known to be highly dynamic, with an appreciable degree of torsional and segmental mobility. In this context, we have earlier utilized the red edge excitation shift (REES) approach to report the retention of restricted solvation dynamics and local structure in the vicinity of spectrin tryptophans on urea denaturation and loss of spectrin secondary structure. As a natural progression of our earlier work, in this work, we carried out a biophysical dissection of tryptophan solvation and rotational dynamics in spectrin and its constituent domains, in order to trace the origin of local structure retention observed in denatured spectrin. Our results show that the ankyrin binding domain (and, to a lesser extent, the β-tetramerization domain) is capable of retention of local structure, similar to that observed for intact spectrin. However, all α-chain domains studied exhibit negligible retention of local structure on urea denaturation. Such a stark chain-specific retention of local structure could originate from the fact that the β-chain domains possess specialized functions, where conservation of local (structural) integrity may be a prerequisite for optimum cellular function. To the best of our knowledge, these observations represent one of the first systematic biophysical dissections of spectrin dynamics in terms of its constituent domains and add to emerging literature on comprehensive domain-based analysis of spectrin organization, dynamics, and function.
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Affiliation(s)
- Sreetama Pal
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Dipayan Bose
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
| | - Abhijit Chakrabarti
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
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Ivanov IT, Paarvanova BK. Differential dielectroscopic data on the relation of erythrocyte membrane skeleton to erythrocyte deformability and flicker. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:69-86. [PMID: 33442752 DOI: 10.1007/s00249-020-01491-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/13/2020] [Accepted: 12/20/2020] [Indexed: 10/22/2022]
Abstract
Two dielectric relaxations, βsp (1.5 MHz) and γ1sp (7 MHz), have been detected on spectrin-based membrane skeleton (MS) of red blood cells (RBCs) using the plot of admittance changes at the spectrin denaturation temperature (Ivanov and Paarvanova in Bioelectrochemistry 110: 59-68, 2016, Electrochim Acta 317: 289-300, 2019a). In this study, we treated RBCs and RBC ghost membranes with agents that make membranes rigid and suppress membrane flicker, and studied the effect on βsp and γ1sp relaxations. Diamide (diazene dicarboxylic acid bis-(N,N-dimethylamide)) (up to 0.85 mM), taurine mustard (tris(2-chloroethyl)amine) (up to 2 mM), known to specifically cross-link and stiffen spectrin, and glutaraldehyde (up to 0.044%) all inhibited the relaxations in RBC ghost membranes. Similar inhibition was obtained resealing RBC ghost membranes with 2,3-diphosphoglicerate (up to 15 mM), binding WGA (wheat germ agglutinin) (up to 0.025 mg/ml) to exofacial aspect of RBCs, incubating RBCs in hypotonic (200 mOsm) and hypertonic (600-900 mOsm) media and depleting RBCs of ATP. By contrast, concanavalin A (1 mg/ml) and DIDS (4,4'-diiso-thiocyanato stilbene-2,2'-disulfonic acid) (75 μM, pH 8.2), both known to bind specifically band 3 integral protein of RBCs without effect on RBC membrane rigidity, did not affect the relaxations. We conclude there might be a relation between the strength of dielectric relaxations on MS spectrin and the deformability and flicker of RBC membrane.
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Affiliation(s)
- Ivan T Ivanov
- Department of Physics and Biophysics, Roentgenology and Radiology, Medical Faculty of Thracian University, 6000, Stara Zagora, Bulgaria.
| | - Boyana K Paarvanova
- Department of Physics and Biophysics, Roentgenology and Radiology, Medical Faculty of Thracian University, 6000, Stara Zagora, Bulgaria
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Ivanov I, Paarvanova B. Thermal dielectroscopy study on the vertical and horizontal interactions in erythrocyte sub-membrane skeleton. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.05.159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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