1
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Jain A, Judy E, Kishore N. Analytical Aspects of ANSA-BSA Association: A Thermodynamic and Conformational Approach. J Phys Chem B 2024; 128:5344-5362. [PMID: 38773936 DOI: 10.1021/acs.jpcb.4c01751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2024]
Abstract
Many studies have demonstrated the manner in which ANS interacts with bovine serum albumin (BSA), although they are limited by the extremely low solubility of dye. The present study demonstrates the binding of ANSA dye with BSA, and since this dye can easily replace ANS, it not only simplifies research but also improves sensor accuracy for serum albumin. A combination of calorimetry and spectroscopy has been employed to establish the thermodynamic signatures associated with the interaction of ANSA with the protein and the consequent conformational changes in the latter. The results of differential scanning calorimetry reveal that when the concentration of ANSA in solution is increased, the thermal stability of the protein increases substantially. The fluorescence data demonstrated a decrease in the binding affinity of ANSA with the protein when pH increased but was unable to identify a change in the mode of interaction of the ligand. ITC has demonstrated that the mode of interaction between ANSA and the protein varies from a single set of binding sites at pH 5 and 7.4 to a sequential binding site at pH 10, emphasizing the potential relevance of protein conformational changes. TCSPC experiments suggested a dynamic type in the presence of ANSA. Molecular docking studies suggest that ANSA molecules are able to find ionic centers in the hydrophobic pockets of BSA. The findings further imply that given its ease of use in experiments, ANSA may be a useful probe for tracking the presence of serum albumin and partially folded protein states.
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Affiliation(s)
- Anu Jain
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Eva Judy
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Nand Kishore
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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2
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Rohiwal SS, Ellederova Z, Tiwari AP, Alqarni M, Elazab ST, El-Saber Batiha G, Pawar SH, Thorat ND. Self-assembly of bovine serum albumin (BSA)-dextran bio-nanoconjugate: structural, antioxidant and in vitro wound healing studies. RSC Adv 2021; 11:4308-4317. [PMID: 35424397 PMCID: PMC8694369 DOI: 10.1039/d0ra09301g] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 02/08/2021] [Accepted: 12/27/2020] [Indexed: 11/21/2022] Open
Abstract
Glycation of proteins is often considered as a method to improve their functional properties for promising applications in wound healing. Furthermore, a marked increase in percentage of radical scavenging activity of the conjugates makes it an effective antioxidant synthetic strategy. A simple conjugation process was employed to develop bovine serum albumin-dextran conjugates (BSA-dextran) using Maillard reaction. Higher electrophoretic mobility and surface charge in the prepared conjugates was observed in native PAGE electrophoresis and zeta potential. Moreover, the fluorescence, FTIR and Raman analysis of the BSA-dextran conjugates shows significant shift in the fluorescence and wavelength as a consequence of conjugate formation. In vitro wound healing assay showed increased cell proliferation and migration effect. These finding suggests that BSA-dextran conjugate could open up a new practical way for exploration in the area of wound healing.
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Affiliation(s)
- Sonali S Rohiwal
- Centre for Interdisciplinary Research, D. Y. Patil University Kolhapur - 416006 MH India
- The PIGMOD Center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences Libechov Czech Republic
| | - Z Ellederova
- The PIGMOD Center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences Libechov Czech Republic
| | - Arpita P Tiwari
- Department of Stem Cell and Regenerative Medicine, D.Y. Patil Education Society, Deemed to be University Kolhapur India
| | - Mohammed Alqarni
- Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University P.O. Box 11099 Taif 21944 Saudi Arabia
| | - Sara T Elazab
- Department of Pharmacology, Faculty of Veterinary Medicine, Mansoura University Mansoura 35516 Egypt
| | - Gaber El-Saber Batiha
- Department of Pharmacology, Faculty of Veterinary Medicine, Mansoura University Mansoura 35516 Egypt
| | - Shivaji H Pawar
- Centre for Interdisciplinary Research, D. Y. Patil University Kolhapur - 416006 MH India
- Centre for Innovative and Applied Research, Anekant Education Society, T. C. College Campus Baramati MH India
| | - Nanasaheb D Thorat
- Division of Medical Science, Nuffield Department of Women's & Reproductive Health, University of Oxford Oxford UK
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3
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Feasibility of circular dichroism to study protein structure at extreme concentrations. Int J Biol Macromol 2019; 132:1290-1295. [DOI: 10.1016/j.ijbiomac.2019.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 12/17/2022]
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4
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Del Giudice A, Galantini L, Dicko C, Pavel NV. The effect of fatty acid binding in the acid isomerizations of albumin investigated with a continuous acidification method. Colloids Surf B Biointerfaces 2018; 168:109-116. [DOI: 10.1016/j.colsurfb.2018.03.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/21/2018] [Accepted: 03/24/2018] [Indexed: 10/17/2022]
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5
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Del Giudice A, Dicko C, Galantini L, Pavel NV. Time-Dependent pH Scanning of the Acid-Induced Unfolding of Human Serum Albumin Reveals Stabilization of the Native Form by Palmitic Acid Binding. J Phys Chem B 2017; 121:4388-4399. [DOI: 10.1021/acs.jpcb.7b01342] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alessandra Del Giudice
- Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
| | - Cedric Dicko
- Department
of Chemistry, Division for Pure and Applied Biochemistry, Lund University, Naturvetarvägen 14, 2241 Lund, Sweden
| | - Luciano Galantini
- Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
| | - Nicolae V. Pavel
- Department of Chemistry, Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
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6
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Li L, Yi H, Jia M, Chang M, Zhou Z, Zhang S, Pan H, Chen Y, Chen J, Xu J. Time-Resolved Fluorescence of Water-Soluble Pyridinium Salt: Sensitive Detection of the Conformational Changes of Bovine Serum Albumin. APPLIED SPECTROSCOPY 2016; 70:1733-1738. [PMID: 27324423 DOI: 10.1177/0003702816644609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/15/2016] [Indexed: 06/06/2023]
Abstract
In this paper, we report a pyridinium salt "turn-on" fluorescent probe, 4-[2-(4-Dimethylamino-phenyl)-vinyl]-1-methylpyridinium iodide (p-DASPMI), and applied its time-resolved fluorescence (TRF) to monitor the protein conformational changes. Both the fluorescence lifetime and quantum yield (QY) of p-DASPMI were increased about two orders of magnitude after binding to the protein bovine serum albumin (BSA). The free p-DASPMI in solution presents an ultrashort fluorescence lifetime (12.4 ps), thus it does not interfere the detection of bound p-DASPMI which has nanosecond fluorescence lifetime. Decay-associated spectra (DAS) show that p-DASPMI molecules bind to subdomains IIA and IIIA of BSA. The TRF decay profiles of p-DASPMI can be described by multi-exponential decay function ([Formula: see text]), and the obtained parameters, such as lifetimes ([Formula: see text]), fractional amplitudes ([Formula: see text]), and fractional intensities ([Formula: see text]), may be used to deduce the conformational changes of BSA. The pH and Cu2+ induced conformational changes of BSA were investigated through the TRF of p-DASPMI. The results show that the p-DASPMI is a candidate fluorescent probe in studying the conformational changes of proteins through TRF spectroscopy and microscopy in the visible range.
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Affiliation(s)
- Lei Li
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Hua Yi
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Menghui Jia
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Mengfang Chang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Zhongneng Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China Collaborative Innovation Centre of Extreme Optics, Shanxi University, Taiyuan, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Yan Chen
- Tongji Hospital Affiliated to Tongji University, Shanghai, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China Collaborative Innovation Centre of Extreme Optics, Shanxi University, Taiyuan, China
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7
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Wang Q, Lim M, Liu X, Wang Z, Chen KL. Influence of Solution Chemistry and Soft Protein Coronas on the Interactions of Silver Nanoparticles with Model Biological Membranes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2301-2309. [PMID: 26812241 DOI: 10.1021/acs.est.5b04694] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The influence of solution chemistry and soft protein coronas on the interactions between citrate-coated silver nanoparticles (AgNPs) and model biological membranes was investigated by assembling supported lipid bilayers (SLBs) composed of zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) on silica crystal sensors in a quartz crystal microbalance with dissipation monitoring (QCM-D). Our results show that the deposition rates of AgNPs on unmodified silica surfaces increased with increasing electrolyte concentrations under neutral pH conditions. Similar trends were observed when AgNPs were deposited on SLBs, hence indicating that the deposition of AgNPs on model cell membranes was controlled by electrostatic interactions. In the presence of human serum albumin (HSA) proteins at both pH 7 and pH 2, the colloidal stability of AgNPs was considerably enhanced due to the formation of HSA soft coronas surrounding the nanoparticles. At pH 7, the deposition of AgNPs on SLBs was suppressed in the presence of HSA due to steric repulsion between HSA-modified AgNPs and SLBs. In contrast, pronounced deposition of HSA-modified AgNPs on SLBs was observed at pH 2. This observation was attributed to the reduction of electrostatic repulsion as well as conformation changes of adsorbed HSA under low pH conditions, resulting in the decrease of steric repulsion between AgNPs and SLBs.
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Affiliation(s)
- Qiaoying Wang
- School of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , 1239 Siping Road, Shanghai 200092, PR China
- Department of Geography and Environmental Engineering, Johns Hopkins University , Baltimore, Maryland 21218-2686, United States
| | - Myunghee Lim
- Department of Geography and Environmental Engineering, Johns Hopkins University , Baltimore, Maryland 21218-2686, United States
| | - Xitong Liu
- Department of Geography and Environmental Engineering, Johns Hopkins University , Baltimore, Maryland 21218-2686, United States
| | - Zhiwei Wang
- School of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , 1239 Siping Road, Shanghai 200092, PR China
| | - Kai Loon Chen
- Department of Geography and Environmental Engineering, Johns Hopkins University , Baltimore, Maryland 21218-2686, United States
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8
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Acharya N, Mishra P, Jha SK. Evidence for Dry Molten Globule-Like Domains in the pH-Induced Equilibrium Folding Intermediate of a Multidomain Protein. J Phys Chem Lett 2016; 7:173-179. [PMID: 26700266 DOI: 10.1021/acs.jpclett.5b02545] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The role of van der Waals (vdW) packing interactions compared to the hydrophobic effect in stabilizing the functional structure of proteins is poorly understood. Here we show, using fluorescence resonance energy transfer, dynamic fluorescence quenching, red-edge excitation shift, and near- and far-UV circular dichroism, that the pH-induced structural perturbation of a multidomain protein leads to the formation of a state in which two out of the three domains have characteristics of dry molten globules, that is, the domains are expanded compared to the native protein with disrupted packing interactions but have dry cores. We quantitatively estimate the energetic contribution of vdW interactions and show that they play an important role in the stability of the native state and cooperativity of its structural transition, in addition to the hydrophobic effect. Our results also indicate that during the pH-induced unfolding, side-chain unlocking and hydrophobic solvation occur in two distinct steps and not in a concerted manner, as commonly believed.
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Affiliation(s)
- Nirbhik Acharya
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
| | - Prajna Mishra
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
| | - Santosh Kumar Jha
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
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9
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Chubarov AS, Zakharova OD, Koval OA, Romaschenko AV, Akulov AE, Zavjalov EL, Razumov IA, Koptyug IV, Knorre DG, Godovikova TS. Design of protein homocystamides with enhanced tumor uptake properties for (19)F magnetic resonance imaging. Bioorg Med Chem 2015; 23:6943-54. [PMID: 26462051 DOI: 10.1016/j.bmc.2015.09.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/27/2015] [Accepted: 09/26/2015] [Indexed: 02/06/2023]
Abstract
Straightforward and reliable tools for in vivo imaging of tumors can benefit the studies of cancer development, as well as contribute to successful diagnosis and treatment of cancer. (19)F NMR offers an exceptional quantitative way of in vivo imaging of the infused agents because of the lack of (19)F signals from the endogenous molecules in the body. The purpose of this study is to develop molecular probes with appropriate NMR characteristics and the biocompatibility for in vivo applications using (19)F MRI. We have studied the reaction between perfluorotoluene and homocysteine thiolactone resulting in the formation of N-substituted homocysteine thiolactone derivative. It has been shown that the reaction occurs selectively at the para position. This fluorine-labeled homocysteine thiolactone has been employed for the introduction of a perfluorotoluene group as a (19)F-containing tag into human serum albumin. The modified protein has been studied in terms of its ability to aggregate and promote the formation of free radicals. By comparing the properties of N-perfluorotoluene-homocystamide of albumin with N-homocysteinylated albumin, it has been revealed that blocking of the alpha-amino group of the homocysteine residue in the fluorinated albumin conjugate inhibits the dangerous aggregation process, as well as free radical formation. A dual-labeled albumin-based molecular probe for (19)F MRI and fluorescence microscopy has been obtained by functionalizing the protein with both maleimide of a fluorescent dye and a fluorinated thiolactone derivative. The incubation of cells with this conjugate did not reveal any significant reduction in cell viability with respect to the parent albumin. The perfluorotoluene-labeled albumin has been demonstrated to act as a promising agent for in vivo (19)F MRI.
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Affiliation(s)
- Alexey S Chubarov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 630090 Novosibirsk, Russia; Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Olga D Zakharova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 630090 Novosibirsk, Russia
| | - Olga A Koval
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 630090 Novosibirsk, Russia
| | | | - Andrey E Akulov
- Institute of Cytology and Genetics, SB RAS, 630090 Novosibirsk, Russia
| | | | - Ivan A Razumov
- Institute of Cytology and Genetics, SB RAS, 630090 Novosibirsk, Russia
| | - Igor V Koptyug
- International Tomography Center, SB RAS, 630090 Novosibirsk, Russia
| | - Dmitry G Knorre
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 630090 Novosibirsk, Russia
| | - Tatyana S Godovikova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, 630090 Novosibirsk, Russia; Novosibirsk State University, 630090 Novosibirsk, Russia.
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10
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Thermal induced unfolding of human serum albumin isomers: Assigning residual α helices to domain II. Int J Biol Macromol 2015; 75:447-52. [DOI: 10.1016/j.ijbiomac.2015.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/02/2015] [Accepted: 02/04/2015] [Indexed: 11/23/2022]
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11
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Cao C, Lei J, Huang T, Du FP. Impact of ionic liquid-type imidazolium surfactant addition on dynamic properties of BSA adsorption layers at different pH. SOFT MATTER 2014; 10:8896-8904. [PMID: 25278154 DOI: 10.1039/c4sm01666a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The dynamic interfacial properties of mixed solutions of bovine serum albumin (BSA) and the ionic liquid-type imidazolium surfactant ([C16mim]Br) were measured as a function of the interface age, surfactant concentration and solution pH. Three BSA conformers were investigated: the normal N form as well as the fast F and aged A forms, corresponding to the different solution pH, respectively. The interfacial tension and the interfacial dilational elasticity isotherms for the mixed adsorption layers indicate that the addition of [C16mim]Br to the different structures of BSA isomers influences the properties of the adsorption layer at the decane/water interface. The addition of [C16mim]Br does not influence the structure of the protein at pH below the isoelectric point of BSA, but at higher solution pH, the addition of surfactants significantly influences the dynamic interfacial properties of BSA solutions due to the electrostatic interaction between the components.
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Affiliation(s)
- Chong Cao
- Department of Applied Chemistry, College of Science, China Agriculture University, Beijing, 100193, China.
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12
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Comparative studies on the heterogeneity of plasma-derived and recombinant human albumins in laboratory use. Int J Biol Macromol 2014; 69:79-87. [DOI: 10.1016/j.ijbiomac.2014.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/01/2014] [Accepted: 05/05/2014] [Indexed: 12/13/2022]
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13
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Masuda T, Chinen H, Fukada K. Effects of Protein Concentration and pH on Oil Droplet Size in O/W Emulsions Stabilized by Bovine Serum Albumin. CHEM LETT 2014. [DOI: 10.1246/cl.131176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Takeshi Masuda
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University
| | - Hitomi Chinen
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University
| | - Kazuhiro Fukada
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University
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14
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Ghosh D, Mondal S, Ghosh S, Saha A. Protein conformation driven biomimetic synthesis of semiconductor nanoparticles. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c1jm13730a] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Liu Y, Zhang L, Liu R, Zhang P. Spectroscopic Identification of Interactions of Pb2+ with Bovine Serum Albumin. J Fluoresc 2011; 22:239-45. [DOI: 10.1007/s10895-011-0950-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 08/07/2011] [Indexed: 10/17/2022]
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16
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Tsai DH, DelRio FW, Keene AM, Tyner KM, MacCuspie RI, Cho TJ, Zachariah MR, Hackley VA. Adsorption and conformation of serum albumin protein on gold nanoparticles investigated using dimensional measurements and in situ spectroscopic methods. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2464-77. [PMID: 21341776 DOI: 10.1021/la104124d] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The adsorption and conformation of bovine serum albumin (BSA) on gold nanoparticles (AuNPs) were interrogated both qualitatively and quantitatively via complementary physicochemical characterization methods. Dynamic light scattering (DLS), asymmetric-flow field flow fractionation (AFFF), fluorescence spectrometry, and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy were combined to characterize BSA-AuNP conjugates under fluid conditions, while conjugates in the aerosol state were characterized by electrospray-differential mobility analysis (ES-DMA). The presence of unbound BSA molecules interferes with DLS analysis of the conjugates, particularly as the AuNP size decreases (i.e., below 30 nm in diameter). Under conditions where the γ value is high, where γ is defined as the ratio of scattering intensity by AuNPs to the scattering intensity by unbound BSA, DLS size results are consistent with results obtained after fractionation by AFFF. Additionally, the AuNP hydrodynamic size exhibits a greater proportional increase due to BSA conjugation at pH values below 2.5 compared with less acidic pH values (3.4-7.3), corresponding with the reversibly denatured (E or F form) conformation of BSA below pH 2.5. Over the pH range from 3.4 to 7.3, the hydrodynamic size of the conjugate is nearly constant, suggesting conformational stability over this range. Because of the difference in the measurement environment, a larger increase of AuNP size is observed following BSA conjugation when measured in the wet state (i.e., by DLS and AFFF) compared to the dry state (by ES-DMA). Molecular surface density for BSA is estimated based on ES-DMA and fluorescence measurements. Results from the two techniques are consistent and similar, but slightly higher for ES-DMA, with an average adsorbate density of 0.015 nm(-2). Moreover, from the change of particle size, we determine the extent of adsorption for BSA on AuNPs using DLS and ES-DMA at 21 °C, which show that increasing the concentration of BSA increases the measured change in AuNP size. Using ES-DMA, we observe that the BSA surface density reaches 90% of saturation at a solution phase concentration between 10 and 30 μmol/L, which is roughly consistent with fluorescence and ATR-FTIR results. The equilibrium binding constant for BSA on AuNPs is calculated by applying the Langmuir equation, with resulting values ranging from 0.51 × 10(6) to 1.65 × 10(6) L/mol, suggesting a strong affinity due to bonding between the single free exterior thiol on N-form BSA (associated with a cysteine residue) and the AuNP surface. Moreover, the adsorption interaction induces a conformational change in BSA secondary structure, resulting in less α-helix content and more open structures (β-sheet, random, or expanded).
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Affiliation(s)
- De-Hao Tsai
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899-8520, United States
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17
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Bhattacharya M, Jain N, Bhasne K, Kumari V, Mukhopadhyay S. pH-Induced conformational isomerization of bovine serum albumin studied by extrinsic and intrinsic protein fluorescence. J Fluoresc 2010; 21:1083-90. [PMID: 21128099 DOI: 10.1007/s10895-010-0781-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 11/25/2010] [Indexed: 11/30/2022]
Abstract
Serum albumins are multi-domain all α-helical proteins that are present in the circulatory system and aid in the transport of a variety of metabolites, endogenous ligands, drugs etc. Earlier observations have indicated that serum albumins adopt a range of reversible conformational isomers depending on the pH of the solution. Herein, we report the concurrent changes in the protein conformation and size that are inherent to the pH-induced conformational isomers of bovine serum albumin (BSA). We have investigated the fluorescence properties of both intrinsic (tryptophan) and extrinsic (ANS, pyrene) fluorophores to shed light into the structural features of the pH-dependent conformers. We have been able to identify a number of conformational isomers using multiple fluorescence observables as a function of pH titration. Our results indicate that at pH 3, a partially-folded, 'molten-globule-like' state is populated. Moreover, equilibrium unfolding studies indicated that the 'molten-globule-like' state unfolds in a non-cooperative fashion and is thermodynamically less stable than the native state. The fluorescence-based approach described in the present work has implications in the study of pH-induced conformational plasticity of other physiologically relevant proteins.
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Affiliation(s)
- Mily Bhattacharya
- Indian Institute of Science Education and Research (IISER), Mohali, Sector 81, S.A.S Nagar, Mohali 160062 Punjab, India
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18
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Characterization of human serum albumin forms with pH. Fluorescence lifetime studies. J Pharm Biomed Anal 2010; 51:1097-102. [DOI: 10.1016/j.jpba.2009.11.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 11/08/2009] [Accepted: 11/09/2009] [Indexed: 11/21/2022]
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19
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Era S, Sogami M, Kuwata K. Comparative 1H NMR studies on the structural looseness of the aged (A) and non-aged (N) bovine mercaptalbumin in the alkaline region. Int J Biol Macromol 2009; 44:37-42. [DOI: 10.1016/j.ijbiomac.2008.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 09/22/2008] [Accepted: 09/26/2008] [Indexed: 10/21/2022]
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20
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Khan SN, Islam B, Yennamalli R, Sultan A, Subbarao N, Khan AU. Interaction of mitoxantrone with human serum albumin: Spectroscopic and molecular modeling studies. Eur J Pharm Sci 2008; 35:371-82. [DOI: 10.1016/j.ejps.2008.07.010] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2008] [Revised: 07/19/2008] [Accepted: 07/22/2008] [Indexed: 10/21/2022]
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21
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Bito R, Shikano T, Kawabata H. Isolation and characterization of denatured serum albumin from rats with endotoxicosis. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1646:100-11. [PMID: 12637016 DOI: 10.1016/s1570-9639(03)00002-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Due to its rapid breakdown in the body, denatured serum albumin has not been identified in biological samples. In this study we attempted to determine whether denatured albumin could be identified in rats with endotoxicosis. Male Wistar rats were injected with lipopolysaccharide (LPS; 5 mg/kg body weight). Plasma albumin concentration decreased to one-third the normal level at 2 days after the injection. By using the purified IgG against the specific epitope of chemically denatured albumin, two immunoreactive plasma proteins (bands D2 and D3) were identified by native PAGE followed by Western blot analysis. The plasma concentration of these two proteins increased significantly at 1 and 1.5 days after LPS injection. Peptide mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI/TOF-MS) identified these two proteins as serum albumin. In order to characterize their conformational nature, ion-exchange chromatography was used to isolate D2 and D3 albumins from rats injected with LPS. Far- and near-UV circular dichroism (CD), tryptophan and 1-anilino-8-naphthalenesulfonate (ANS) fluorescence, and proteolytic susceptibility showed conformational alterations in the D2 and D3 albumins as compared with native albumin. These data indicate the presence of denatured albumin in circulating rat plasma, and this fact may contribute to a further understanding of the molecular mechanisms of albumin breakdown in physiological and pathophysiological conditions.
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Affiliation(s)
- Ryuji Bito
- Laboratory for Nutritional Biochemistry, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki City, Kanagawa 214-8571, Japan
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22
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Murayama K, Wu Y, Czarnik-Matusewicz B, Ozaki Y. Two-Dimensional/Attenuated Total Reflection Infrared Correlation Spectroscopy Studies on Secondary Structural Changes in Human Serum Albumin in Aqueous Solutions: pH-Dependent Structural Changes in the Secondary Structures and in the Hydrogen Bondings of Side Chains. J Phys Chem B 2001. [DOI: 10.1021/jp004537a] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Koichi Murayama
- Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662-8501, Japan, Department of Environment Information and Bio-production Engineering, Faculty of Agriculture, Kobe University, Nada-ku, Kobe 657-8501, Japan
| | - Yuqing Wu
- Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662-8501, Japan, Department of Environment Information and Bio-production Engineering, Faculty of Agriculture, Kobe University, Nada-ku, Kobe 657-8501, Japan
| | - Bogusława Czarnik-Matusewicz
- Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662-8501, Japan, Department of Environment Information and Bio-production Engineering, Faculty of Agriculture, Kobe University, Nada-ku, Kobe 657-8501, Japan
| | - Yukihiro Ozaki
- Department of Chemistry, School of Science, Kwansei-Gakuin University, Uegahara, Nishinomiya 662-8501, Japan, Department of Environment Information and Bio-production Engineering, Faculty of Agriculture, Kobe University, Nada-ku, Kobe 657-8501, Japan
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23
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Arai M, Kuwajima K. Role of the molten globule state in protein folding. ADVANCES IN PROTEIN CHEMISTRY 2000; 53:209-82. [PMID: 10751946 DOI: 10.1016/s0065-3233(00)53005-8] [Citation(s) in RCA: 355] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- M Arai
- Department of Physics, School of Science, University of Tokyo, Japan
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Dockal M, Carter DC, Rüker F. Conformational transitions of the three recombinant domains of human serum albumin depending on pH. J Biol Chem 2000; 275:3042-50. [PMID: 10652284 DOI: 10.1074/jbc.275.5.3042] [Citation(s) in RCA: 357] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Human serum albumin (HSA) is a protein of 66.5 kDa that is composed of three homologous domains, each of which displays specific structural and functional characteristics. HSA is known to undergo different pH-dependent structural transitions, the N-F and F-E transitions in the acid pH region and the N-B transition at slightly alkaline pH. In order to elucidate the structural behavior of the recombinant HSA domains as stand-alone proteins and to investigate the molecular and structural origins of the pH-induced conformational changes of the intact molecule, we have employed fluorescence and circular dichroic methods. Here we provide evidence that the loosening of the HSA structure in the N-F transition takes place primarily in HSA-DOM III and that HSA-DOM I undergoes a structural rearrangement with only minor changes in secondary structure, whereas HSA-DOM II transforms to a molten globule-like state as the pH is reduced. In the pH region of the N-B transition of HSA, HSA-DOM I and HSA-DOM II experience a tertiary structural isomerization, whereas with HSA-DOM III no alterations in tertiary structure are observed, as judged from near-UV CD and fluorescence measurements.
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Affiliation(s)
- M Dockal
- Institute of Applied Microbiology, University of Agricultural Sciences, Muthgasse 18, A-1190 Vienna, Austria
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