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Ju H, Liu Y, Wang Y, Lu R, Yang B, Wang D, Wang J. The cellular response and molecular mechanism of superoxide dismutase interacting with superparamagnetic iron oxide nanoparticles. NANOIMPACT 2024; 35:100515. [PMID: 38857755 DOI: 10.1016/j.impact.2024.100515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/17/2024] [Accepted: 05/31/2024] [Indexed: 06/12/2024]
Abstract
This study explored the response of superoxide dismutase (SOD) under superparamagnetic iron oxide nanoparticles (SPIONs)-induced oxidative stress using combined cellular and molecular methods. Results found that SPIONs induced the inhibition of catalase activity, the U-inverted change of SOD activity and the accumulation of reactive oxygen species (ROS), leading to oxidative damage and cytotoxicity. The change of intracellular SOD activity was resulted from the increase of molecular activity induced by directly interacting with SPIONs and ROS-inhibition of activity. The increase of molecular activity could be attributed to the structural and conformational changes of SOD, which were caused by the direct interaction of SOD with SPIONs. The SOD-SPIONs interaction and its interacting mechanism were explored by multi-spectroscopy, isothermal titration calorimetry and zeta potential assays. SOD binds to SPIONs majorly via hydrophobic forces with the involvement of electrostatic forces. SPIONs approximately adsorb 11 units of SOD molecule with the binding affinity of 2.99 × 106 M-1. The binding sites on SOD were located around Tyr residues, whose hydrophilicity increased upon interacting with SPIONs. The binding to SPIONs loosened the peptide chains, changed the secondary structure and reduced the aggregation state of SOD.
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Affiliation(s)
- Hao Ju
- School of Environmental and Material Engineering, Yantai University, 30# Qingquan Road, Yantai 264005, PR China
| | - Yue Liu
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding 071002, PR China
| | - Yameng Wang
- Chinese Academy for Environmental Planning, Building 1, No. 15, Shixing Street, Shijingshan District, Beijing 100041, PR China
| | - Rui Lu
- Test Experiment Center, Shandong Institute of Space Electronic Technology, 513# Hangtian Road, Yantai 264670, PR China
| | - Bin Yang
- School of Environmental and Material Engineering, Yantai University, 30# Qingquan Road, Yantai 264005, PR China
| | - Deyi Wang
- School of Environmental and Material Engineering, Yantai University, 30# Qingquan Road, Yantai 264005, PR China.
| | - Jing Wang
- School of Environmental and Material Engineering, Yantai University, 30# Qingquan Road, Yantai 264005, PR China.
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Wolkersdorfer AM, Jugovic I, Scheller L, Gutmann M, Hahn L, Diessner J, Lühmann T, Meinel L. PEGylation of Human Vascular Endothelial Growth Factor. ACS Biomater Sci Eng 2024; 10:149-155. [PMID: 37296497 DOI: 10.1021/acsbiomaterials.3c00253] [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] [Indexed: 06/12/2023]
Abstract
Vascular endothelial growth factor A-165 (VEGF-A165) positively modulates neointimal hyperplasia, lumen stenosis, and neovascularization. One challenge for the use of VEGF-A165 for potential therapy is its short serum half-life. Therefore, we are designing VEGF-A165 bioconjugates carrying polyethylene glycol (PEG). The purity of the recombinantly expressed human VEGF-A165 exceeded 90%. The growth factor had a half-maximal effective concentration of 0.9 ng/mL (EC50) and induced tube formation of human umbilical vein endothelial cells. PEGylation was conducted by Schiff base reaction followed by reductive amination. After purification, two species were obtained, with one or two PEG attached per VEGF-A165 dimer. Both resulting bioconjugates had a purity exceeding 90%, wild-type bioactivity, and increased hydrodynamic radii as required for prolonging the half-life.
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Affiliation(s)
- Alena Maria Wolkersdorfer
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Isabelle Jugovic
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Lena Scheller
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Marcus Gutmann
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Lukas Hahn
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Joachim Diessner
- University of Würzburg, Department of Obstetrics and Gynecology, Josef-Schneider-Straße 14, Würzburg DE-97080, Germany
| | - Tessa Lühmann
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
| | - Lorenz Meinel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, University, Am Hubland, Würzburg DE-97074, Germany
- Helmholtz Centre for Infection Research, Helmholtz-Institute for RNA-based Infection Research (HIRI), Josef-Schneider-Strasse 2/D15, Würzburg 97080, Germany
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Raw J, Franco LR, de C. Rodrigues LF, Barbosa LRS. Unveiling the Three-Step Model for the Interaction of Imidazolium-Based Ionic Liquids on Albumin. ACS OMEGA 2023; 8:38101-38110. [PMID: 37867681 PMCID: PMC10586182 DOI: 10.1021/acsomega.3c04188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/08/2023] [Indexed: 10/24/2023]
Abstract
The effect of the ionic liquids (ILs) 1-methyl-3-tetradecylimidazolium chloride ([C14MIM][Cl]), 1-dodecyl-3-methylimidazolium chloride ([C12MIM][Cl]), and 1-decyl-methylimidazolium chloride ([C10MIM][Cl]) on the structure of bovine serum albumin (BSA) was investigated by fluorescence spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, small-angle X-ray scattering (SAXS), and molecular dynamics (MD) simulations. Concerning the fluorescence measurements, we observed a blue shift and a fluorescence quenching as the IL concentration increased in the solution. Such behavior was observed for all three studied imidazolium-based ILs, being larger as the number of methylene groups in the alkyl chain increased. UV-vis absorbance measurements indicate that even at relatively small IL/protein ratios, like 1:1 or 1:2, ([C14MIM][Cl]) is able to change, at least partially, the sample turbidity. SAXS results agree with the spectroscopic techniques and suggest that the proteins underwent partial unfolding, evidenced by an increase in the radius of gyration (Rg) of the scattering particle. In the absence and presence of ([C14MIM][Cl]) = 3 mM BSA Rg increases from 29.1 to 45.1 Å, respectively. Together, these results indicate that the interaction of BSA with ILs is divided into three stages: the first stage is characterized by the protein in its native form. It takes place for protein/IL ≤ 1:2, and the interaction is predominantly due to the electrostatic forces provided by the negative charges on the surface of BSA and the cationic polar head of the ILs. In the second stage, higher IL concentrations induce the unfolding of the protein, most likely inducing the unfolding of domains I and III, in such a way that the protein's secondary structure is kept almost unaltered. In the last stage, IL micelles start to form, and therefore, the interaction with protein reaches a saturation point and free micelles may be formed. We believe that this work provides new information about the interaction of ILs with BSA.
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Affiliation(s)
- Juliana Raw
- Department
of General Physics, University of São
Paulo, Institute of Physics, São Paulo 05508-000, SP, Brazil
| | - Leandro R. Franco
- Department
of Engineering and Physics, Karlstad University, Karlstad 65188, Sweden
| | - Luiz Fernando de C. Rodrigues
- Department
of General Physics, University of São
Paulo, Institute of Physics, São Paulo 05508-000, SP, Brazil
- Brazilian
Synchrotron Light Laboratory (LNLS), Brazilian
Center for Research in Energy and Materials (CNPEM), Campinas 13083-100, SP Brazil
| | - Leandro R. S. Barbosa
- Department
of General Physics, University of São
Paulo, Institute of Physics, São Paulo 05508-000, SP, Brazil
- Brazilian
Synchrotron Light Laboratory (LNLS), Brazilian
Center for Research in Energy and Materials (CNPEM), Campinas 13083-100, SP Brazil
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Dyagala S, Paul M, Aswal VK, Biswas S, Saha SK. Compaction of Calf Thymus DNA by a Potential One-Head-Two-Tail Surfactant: Properties of Nanomaterials and Biological Testing for Gene Delivery. ACS APPLIED BIO MATERIALS 2023; 6:3848-3862. [PMID: 37647161 DOI: 10.1021/acsabm.3c00470] [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] [Indexed: 09/01/2023]
Abstract
A one-head-two-tail cationic surfactant, Dilauryldimethylammonium bromide (DDAB) has shown a great extent of calf thymus DNA (ct-DNA) compaction being adsorbed on the surfaces of negatively charged SiO2 nanoparticles (NPs). DDAB molecules show high adsorption efficiency and induce many positive surface charges per-unit surface area of the SiO2 NPs compared to cationic Gemini (12-6-12) and conventional (DTAB) surfactants in an aqueous medium at pH 7.4, as evident from zeta potential and EDAX data. Transmission electron microscopy and field emission scanning electron microscopy images, along with ethidium bromide exclusion assay and DLS data support the compaction of ct-DNA. Fluorescence microscopic images show that in the presence of SiO2 NPs, DDAB can perform 50% compaction of ct-DNA at a concentration ∼58% and ∼99% lower than that of 12-6-12 and DTAB, respectively. Better ct-DNA compaction by DDAB is evident compared to other Gemini surfactants (12-4-12 and 12-8-12) as well reported before. Time-correlated single photon counting fluorescence intensity decay measurements of a probe DAPI in ct-DNA have revealed the average lifetime value that is decreased by ∼61% at 2.5 μM of DDAB in the presence of SiO2 NPs as compared to a decrease by only ∼29% in its absence, supporting NPs-induced stronger surfactant binding with ct-DNA. Fluorescence lifetime data have also demonstrated the crowding effect of NPs. At 2.5 μM of DDAB, both fast and slow rotational relaxation components of DAPI contribute almost equally to depolarization with the absence of NPs; however, with the presence of NPs, ∼96% weightage of the anisotropy decay is for the fast component. The present DDAB-SiO2 NPs combination has proved to be an excellent gene delivery system based on the cell viability in the mouse mammary gland adenocarcinoma cells (4T1) and human embryonic kidney (HEK) 293 cell lines, and in vitro and in vivo studies.
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Affiliation(s)
- Shalini Dyagala
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Milan Paul
- Department of Pharmacy, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Vinod Kumar Aswal
- Solid State Physics Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, Maharashtra 400085, India
| | - Swati Biswas
- Department of Pharmacy, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Subit Kumar Saha
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
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Halder S, Paul M, Dyagala S, Aggrawal R, Aswal VK, Biswas S, Saha SK. Role of Gemini Surfactants with Variable Spacers and SiO 2 Nanoparticles in ct-DNA Compaction and Applications toward In Vitro/ In Vivo Gene Delivery. ACS APPLIED BIO MATERIALS 2023. [PMID: 37277159 DOI: 10.1021/acsabm.3c00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Compaction of calf thymus DNA (ct-DNA) by two cationic gemini surfactants, 12-4-12 and 12-8-12, in the absence and presence of negatively charged SiO2 nanoparticles (NPs) (∼100 nm) has been explored using various techniques. 12-8-12 having a longer hydrophobic spacer induces a greater extent of ct-DNA compaction than 12-4-12, which becomes more efficient with SiO2 NPs. While 50% ct-DNA compaction in the presence of SiO2 NPs occurs at ∼77 nM of 12-8-12 and ∼130 nM of 12-4-12, but a conventional counterpart surfactant, DTAB, does it at its concentration as high as ∼7 μM. Time-resolved fluorescence anisotropy measurements show changes in the rotational dynamics of a fluorescent probe, DAPI, and helix segments in the condensed DNA. Fluorescence lifetime data and ethidium bromide exclusion assays reveal the binding sites of surfactants to ct-DNA. 12-8-12 with SiO2 NPs has shown the highest cell viability (≥90%) and least cell death in the human embryonic kidney (HEK) 293 cell lines in contrast to the cell viability of ≤80% for DTAB. These results show that 12-8-12 with SiO2 NPs has the highest time and dose-dependent cytotoxicity compared to 12-8-12 and 12-4-12 in the murine breast cancer 4T1 cell line. Fluorescence microscopy and flow cytometry are performed for in vitro cellular uptake of YOYO-1-labeled ct-DNA with surfactants and SiO2 NPs using 4T1 cells after 3 and 6 h incubations. The in vivo tumor accumulation studies are carried out using a real-time in vivo imaging system after intravenous injection of the samples into 4T1 tumor-bearing mice. 12-8-12 with SiO2 has delivered the highest amount of ct-DNA in cells and tumors in a time-dependent manner. Thus, the application of a gemini surfactant with a hydrophobic spacer and SiO2 NPs in compacting and delivering ct-DNA to the tumor is proven, warranting its further exploration in nucleic acid therapy for cancer treatment.
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Affiliation(s)
- Sayantan Halder
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Milan Paul
- Department of Pharmacy, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Shalini Dyagala
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Rishika Aggrawal
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Vinod K Aswal
- Solid State Physics Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, Maharashtra 400085, India
| | - Swati Biswas
- Department of Pharmacy, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Subit K Saha
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
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Rajan D, Rajamanikandan R, Ilanchelian M. Investigating the biophysical interaction of serum albumins-gold nanorods using hybrid spectroscopic and computational approaches with the intent of enhancing cytotoxicity efficiency of targeted drug delivery. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
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Comprehensive Assessment of Biomolecular Interactions of Morpholine-Based Mixed Ligand Cu(II) and Zn(II) Complexes of 2,2'-Bipyridine as Potential Anticancer and SARS-CoV-2 Agents: A Synergistic Experimental and Structure-Based Virtual Screening. Bioinorg Chem Appl 2022; 2022:6987806. [PMID: 36545430 PMCID: PMC9763021 DOI: 10.1155/2022/6987806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 12/14/2022] Open
Abstract
A new class of pharmacologically active mixed-ligand complexes (1a-2a) [MII(L)2 (bpy)], where L = 2-(4-morpholinobenzylideneamino)phenol), bpy = 2,2'-bipyridine, MII = Cu (1a), and Zn (2a), were assigned an octahedral geometry by analytical and spectral measurements. Gel electrophoresis showed that complex (1a) demonstrated the complete DNA cleavage mediated by H2O2. The overall DNA-binding constants observed from UV-vis, fluorometric, hydrodynamic, and electrochemical titrations were in the following sequence: (1a) > (2a) > (HL), which suggests that the complexes might intercalate DNA, a possibility that is further supported by the biothermodynamic characteristics. The binding constant results of BSA by electronic absorption and fluorometric titration demonstrate that complex (1a) exhibits the highest binding effectiveness among others, which means that all compounds could interact with BSA through a static approach, additionally supported by FRET measurements. Density FunctionalTheory (DFT) and molecular docking calculations were relied on to unveil the electronic structure, reactivity, and interacting capability of all substances with DNA, BSA, and SARS-CoV-2 main protease (Mpro). These observed binding energies fell within the following ranges: -7.7 to -8.6, -7.2 to -10.2, and -6.7 to -8.2 kcal/mol, respectively. The higher reactivity of the complexes compared to free ligand is supported by the Frontier MolecularOrbital (FMO) theory. The in vitro antibacterial, cytotoxic, and radical scavenging characteristics revealed that complex (1a) has the best biological efficacy compared to others. This is encouraged because all experimental findings are closely correlated with the theoretical measurements.
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Jin L, Gao Y, Sun Z, Jia Y, Shen B, Li X, Geng Q, Mu X. Study on the Interaction between Chalcone and DNA with Spectroscopy and Molecular Docking Technique. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2022.2133946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Lihong Jin
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Yan Gao
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Zihan Sun
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Yi Jia
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Bingjun Shen
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Xiaosha Li
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Qi Geng
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
| | - Xiaoyu Mu
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, PR China
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Halder S, Aggrawal R, Saha SK. Concentration-dependent β-cyclodextrin-promoted refolding of gold nanoparticles-conjugated bovine serum albumin complexed with gemini surfactants with different spacer groups. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128862] [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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Lan Y, He B, Tan CS, Ming D. Applications of Smartphone-Based Aptasensor for Diverse Targets Detection. BIOSENSORS 2022; 12:bios12070477. [PMID: 35884280 PMCID: PMC9312806 DOI: 10.3390/bios12070477] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 06/27/2022] [Accepted: 06/27/2022] [Indexed: 12/17/2022]
Abstract
Aptamers are a particular class of functional recognition ligands with high specificity and affinity to their targets. As the candidate recognition layer of biosensors, aptamers can be used to sense biomolecules. Aptasensors, aptamer-based biosensors, have been demonstrated to be specific, sensitive, and cost-effective. Furthermore, smartphone-based devices have shown their advantages in binding to aptasensors for point-of-care testing (POCT), which offers an immediate or spontaneous responding time for biological testing. This review describes smartphone-based aptasensors to detect various targets such as metal ions, nucleic acids, proteins, and cells. Additionally, the focus is also on aptasensors-related technologies and configurations.
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Affiliation(s)
- Ying Lan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China; (Y.L.); (B.H.)
| | - Baixun He
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China; (Y.L.); (B.H.)
| | - Cherie S. Tan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China; (Y.L.); (B.H.)
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
- Correspondence: (C.S.T.); (D.M.)
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China; (Y.L.); (B.H.)
- Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
- Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
- Correspondence: (C.S.T.); (D.M.)
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Aggrawal R, Halder S, Dyagala S, Saha SK. Refolding of denatured gold nanoparticles-conjugated bovine serum albumin through formation of catanions between gemini surfactant and sodium dodecyl sulphate. RSC Adv 2022; 12:16014-16028. [PMID: 35733677 PMCID: PMC9136644 DOI: 10.1039/d2ra02618j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 05/20/2022] [Indexed: 11/21/2022] Open
Abstract
The present work elucidates binding interactions of sodium dodecyl sulphate (SDS) with the conjugated gold nanoparticles (AuNPs)-bovine serum albumin (BSA), unfolded by each of two gemini surfactants, 1,4-bis(dodecyl-N,N-dimethylammonium bromide)-butane (12-4-12,2Br−) or 1,8-bis(dodecyl-N,N-dimethylammonium bromide)-octane (12-8-12,2Br−). Initially, at a low concentration of SDS there is a relaxation of bioconjugates from their compressed form due to the formation of catanions between SDS and gemini surfactants. On moving towards higher concentrations of SDS, these relaxed unfolded bioconjugates renature by removal of residual bound gemini surfactants. Mixed assemblies of SDS and gemini surfactants formed during refolding of bioconjugates are characterized by DLS and FESEM measurements. A step-by-step process of refolding observed for these denatured protein bioconjugates is exactly the inverse of their unfolding phenomenon. Parameters concerning nanometal surface energy transfer (NSET) and Förster's resonance energy transfer (FRET) phenomenon were employed to develop a binding isotherm. Moreover, there remains an inverse relationship between α-helix and β-turns of bioconjugates during the refolding process. Significantly, in the presence of 12-8-12,2Br−, SDS induces more refolding as compared to that for 12-4-12,2Br−. Bioconjugation shows an effect on the secondary structures of refolded BSA, which has been explored in detail through various studies such as Fourier transform infrared spectroscopy, fluorescence, and circular dichroism (CD). Therefore, this approach vividly describes the refolding of denatured bioconjugates, exploring structural information regarding various catanions formed during the process that would help in understanding distance-dependent optical biomolecular detection methodologies and physicochemical properties. Demonstration of refolding of conjugated AuNPs-BSA through the formation of various catanions of SDS and gemini surfactants with different spacers in HEPES buffer medium using FRET/NSET methods and material characterization techniques.![]()
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Affiliation(s)
- Rishika Aggrawal
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Sayantan Halder
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Shalini Dyagala
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
| | - Subit K. Saha
- Department of Chemistry, Birla Institute of Technology & Science (BITS) Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India
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