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Bisaria I, Chauhan C, Muthu SA, Parvez S, Ahmad B. The effect of chrysin binding on the conformational dynamics and unfolding pathway of human serum albumin. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 316:124332. [PMID: 38676982 DOI: 10.1016/j.saa.2024.124332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/20/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Studies on the interactions between ligands and proteins provide insights into how a possible medication alters the structures and activities of the target or carrier proteins. The natural flavonoid aglycone Chrysin (CHR) has demonstrated anti-inflammatory, antioxidant, antiapoptotic, neuroprotective, and antineoplastic effects, both in vitro and in vivo. In this work, we investigated the impact of CHR binding on the as-yet-unexplored conformation, dynamics, and unfolding mechanism of human serum albumin (HSA). We determined CHR binding to HSA domain-II with the association constant (Ka) of 2.70 ± 0.21 × 105 M-1. The urea-induced sequential unfolding mechanism of HSA was used to elucidate the debatable binding location of CHR. CHR binding induced both secondary and tertiary structural alterations in the protein as studied by far-UV circular dichroism and intrinsic fluorescence spectroscopy. Red edge excitation shift (REES) indicated a decrease in conformational dynamics of the protein on the complex formation. This suggested an ordered compact and spatial arrangement of the CHR-boundmolecule. The binding of CHR was found to significantly modulate the urea-induced unfolding pathway of HSA. Urea-induced unfolding pathway of HSA became a two-state process (N-U) from a three-state process (N-I-U). The interaction of CHR is found to increase the thermal stability of the protein by ∼4 °C. This study focuses on the fundamental sciences and demonstrates how prospective medication compounds can alter the dynamics and stability of protein structure.
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Affiliation(s)
- Ishita Bisaria
- Protein Assembly Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Chanchal Chauhan
- Protein Assembly Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India; Department of Molecular Medicine, School of Interdisciplinary Studies, Jamia Hamdard, New Delhi 110062, India
| | - Shivani A Muthu
- Protein Assembly Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India; Department of Molecular Medicine, School of Interdisciplinary Studies, Jamia Hamdard, New Delhi 110062, India
| | - Suhel Parvez
- Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Basir Ahmad
- Protein Assembly Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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Zargar S, Wani TA, Alsaif NA, Khayyat AIA. A Comprehensive Investigation of Interactions between Antipsychotic Drug Quetiapine and Human Serum Albumin Using Multi-Spectroscopic, Biochemical, and Molecular Modeling Approaches. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27082589. [PMID: 35458787 PMCID: PMC9029314 DOI: 10.3390/molecules27082589] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/06/2022] [Accepted: 04/13/2022] [Indexed: 12/28/2022]
Abstract
Quetiapine (QTP) is a short-acting atypical antipsychotic drug that treats schizophrenia or manic episodes of bipolar disorder. Human serum albumin (HSA) is an essential transport protein that transports hormones and various other ligands to their intended site of action. The interactions of QTP with HSA and their binding mechanism in the HSA-QTP system was studied using spectroscopic and molecular docking techniques. The UV-Vis absorption study shows hyperchromicity in the spectra of HSA on the addition of QTP, suggesting the complex formation and interactions between QTP and HSA. The results of intrinsic fluorescence indicate that QTP quenched the fluorescence of HSA and confirmed the complex formation between HSA and QTP, and this quenching mechanism was a static one. Thermodynamic analysis of the HSA-QTP system confirms the involvement of hydrophobic forces, and this complex formation is spontaneous. The competitive displacement and molecular docking experiments demonstrated that QTP is preferentially bound to HSA subdomain IB. Furthermore, the CD experiment results showed conformational changes in the HSA-QTP system. Besides this, the addition of QTP does not affect the esterase-like activity of HSA. This study will help further understand the credible mechanism of transport and delivery of QTP via HSA and design new QTP-based derivatives with greater efficacy.
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Affiliation(s)
- Seema Zargar
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 22452, Riyadh 11451, Saudi Arabia; (S.Z.); (A.I.A.K.)
| | - Tanveer A. Wani
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia;
- Correspondence:
| | - Nawaf A. Alsaif
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia;
| | - Arwa Ishaq A. Khayyat
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 22452, Riyadh 11451, Saudi Arabia; (S.Z.); (A.I.A.K.)
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Quantification of Structural Integrity and Stability Using Nanograms of Protein by Flow-Induced Dispersion Analysis. Molecules 2022; 27:molecules27082506. [PMID: 35458703 PMCID: PMC9027858 DOI: 10.3390/molecules27082506] [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: 02/23/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 12/04/2022] Open
Abstract
In the development of therapeutic proteins, analytical assessment of structural stability and integrity constitutes an important activity, as protein stability and integrity influence drug efficacy, and ultimately patient safety. Existing analytical methodologies solely rely on relative changes in optical properties such as fluorescence or scattering upon thermal or chemical perturbation. Here, we present an absolute analytical method for assessing protein stability, structure, and unfolding utilizing Taylor dispersion analysis (TDA) and LED-UV fluorescence detection. The developed TDA method measures the change in size (hydrodynamic radius) and intrinsic fluorescence of a protein during in-line denaturation with guanidinium hydrochloride (GuHCl). The conformational stability of the therapeutic antibody adalimumab and human serum albumin were characterized as a function of pH. The simple workflow and low sample consumption (40 ng protein per data point) of the methodology make it ideal for assessing protein characteristics related to stability in early drug development or when having a scarce amount of sample available.
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Mukherjee M, Saha Sardar P, Basu Roy M, Mukherjee P, Ghosh R, Ghosh S. Tracking Zone-wise perturbation during unfolding of some globular proteins using Eu(III) complex of Tetracycline as a probe exhibiting Stark splitting. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 264:120231. [PMID: 34365134 DOI: 10.1016/j.saa.2021.120231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/14/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
Enhanced 'Antenna effect' of a suitably designed ternary complex of Eu(III), Tetracycline hydrochloride (TC) and globular proteins viz bovine serum albumin (BSA), human serum albumin (HSA) and β-lactoglobulin A (BLGA) in aqueous medium is employed to characterize the different partially unfolded states along with investigation of the micro- heterogeneous environment of the proteins during their stepwise unfolding. The zone-wise perturbation for the proteins upon denaturation by Urea and Guanidine hydrochloride (Gdn. HCl) is followed by the emission of Eu(III) through 'Antenna Effect' and that of the tryptophan (Trp) residues of the proteins as a function of denaturants both by steady state and time resolved emission study. With Gdn. HCl as denaturant, both BSA and BLGA show quenching of Eu(III) emission compared to pure protein while HSA exhibits an enhancement of antenna effect during unfolding as compared to that in its absence. In the presence of Urea, HSA and BSA show enhancement of antenna effect accompanied by Stark splitting of the 5D0→7F2 transition of Eu(III) although BLGA follows the similar pattern of quenching of Eu(III) emission as observed with Gdn. HCl without any Stark splitting. The proteins exhibit a two state transition with ΔGD values of ~ 2-3 kcal mol-1. Thus the use of Eu(III) emission as an efficient probe is advocating here to rationalize the microenvironment of the proteins during their stepwise unfolding.
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Affiliation(s)
- Moumita Mukherjee
- Present Address: Sri Aurobindo Vidyamandir, Chandannagar, Hoogly, West Bengal, India
| | - Pinki Saha Sardar
- Department of Chemistry, The Bhawanipur Education Society College, Kolkata-700020, West Bengal, India
| | - Maitrayee Basu Roy
- Department of Chemistry, Vidyasagar College for Women, Kolkata-700006, West Bengal, India
| | - Priyanka Mukherjee
- Department of Chemistry and Biochemistry, Asutosh College, Kolkata-700026, India
| | - Rina Ghosh
- Department of Chemistry, St. Xavier's College, Kolkata-700013, India
| | - Sanjib Ghosh
- Department of Chemistry, Adamas University, Barasat, West Bengal, India.
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Mohan V, Sengupta B, Das N, Banerjee I, Sen P. Domain-Specific Stabilization of Structural and Dynamic Responses of Human Serum Albumin by Sucrose. Protein Pept Lett 2019; 26:287-300. [DOI: 10.2174/0929866526666190122115702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/03/2019] [Accepted: 01/12/2019] [Indexed: 11/22/2022]
Abstract
Background:Human Serum Albumin (HSA) is the most abundant protein present in human blood plasma. It is a large multi-domain protein with 585 amino acid residues. Due to its importance in human body, studies on the interaction of HSA with different external agent is of vital interest. The denaturation and renaturation of HSA in presence of external agents are of particular interest as they affect the biological activity of the protein.Objective:The objective of this work is to study the domain-specific and overall structural and dynamical changes occurring to HSA in the presence of a denaturing agent, urea and a renaturing agent, sucrose.Methods:In order to carry out the domain-specific studies, HSA has been tagged using N-(7- dimethylamino-4-methylcoumarin-3-yl) iodoacetamide (DACIA) at Cys-34 of domain-I and pnitrophenyl coumarin ester (NPCE) at Tyr-411 site in domain-III, separately. Steady-state absorption, emission and solvation dynamic measurements have been carried out in order to monitor the domain-specific alteration of HSA caused by the external agents. The overall structural change of HSA have been monitored using circular dichroism spectroscopy.Results:The α-helicity of HSA was found to decrease from 65% to 11% in presence of urea and was found to further increase to 25% when sucrose is added, manifesting the denaturing and renaturing effects of urea and sucrose, respectively. The steady state studies show that domain-III is more labile towards denaturation as compared to domain-I. The presence of an intermediate state is observed during the denaturation process. The stabilization of this intermediate state in presence of sucrose is attributed as the reason for the stabilization of HSA by sucrose. From solvation dynamics studies, it could be seen that the solvation time of DACIA inside domain-I of HSA decreases and increases regularly with increasing concentrations of urea and sucrose, respectively, while in the case of NPCE-tagged domain-III, the effect of sucrose on solvation time is evident only at high concentrations of urea.Conclusion:The denaturing and renaturing effects of urea and sucrose could be clearly seen from the steady state studies and circular dichroism spectroscopy measurements. A regular change in solvation time could only be observed in the case of domain-I and not in domain-III. The results indicate that the renaturing effect of sucrose on domain-III is not very evident when protein is in its native state, but is evident in when the protein is denatured.</P>
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Affiliation(s)
- Vaisakh Mohan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur - 208 016, UP, India
| | - Bhaswati Sengupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur - 208 016, UP, India
| | - Nilimesh Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur - 208 016, UP, India
| | - Indrani Banerjee
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur - 208 016, UP, India
| | - Pratik Sen
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur - 208 016, UP, India
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Pedersen ME, Gad SI, Østergaard J, Jensen H. Protein Characterization in 3D: Size, Folding, and Functional Assessment in a Unified Approach. Anal Chem 2019; 91:4975-4979. [DOI: 10.1021/acs.analchem.9b00537] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Morten E. Pedersen
- FIDA-Tech ApS, Universitetsparken 2 (C/O University of Copenhagen), 2100 Copenhagen, Denmark
| | - Sarah I. Gad
- FIDA-Tech ApS, Universitetsparken 2 (C/O University of Copenhagen), 2100 Copenhagen, Denmark
| | - Jesper Østergaard
- FIDA-Tech ApS, Universitetsparken 2 (C/O University of Copenhagen), 2100 Copenhagen, Denmark
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Henrik Jensen
- FIDA-Tech ApS, Universitetsparken 2 (C/O University of Copenhagen), 2100 Copenhagen, Denmark
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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7
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Nosrati H, Abbasi R, Charmi J, Rakhshbahar A, Aliakbarzadeh F, Danafar H, Davaran S. Folic acid conjugated bovine serum albumin: An efficient smart and tumor targeted biomacromolecule for inhibition folate receptor positive cancer cells. Int J Biol Macromol 2018; 117:1125-1132. [DOI: 10.1016/j.ijbiomac.2018.06.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/03/2018] [Accepted: 06/06/2018] [Indexed: 01/18/2023]
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8
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Zhang H, Wang Y, Zhu H, Fei Z, Cao J. Binding mechanism of triclocarban with human serum albumin: Effect on the conformation and activity of the model transport protein. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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9
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Wu Y, Zhang H, Wang Y. Conformational and functional changes of bovine serum albumin induced by TiO2 nanoparticles binding. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.07.116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Mitra AK, Sau A, Pal U, Saha C, Basu S. Constrained Photophysics of 5,7-dimethoxy-2,3,4,9-tetrahydro-1H-carbazol-1-one in the Bioenvironment of Serum Albumins: A Spectroscopic Endeavour Supported by Molecular Docking Analysis. J Fluoresc 2017; 27:1547-1558. [PMID: 28434063 DOI: 10.1007/s10895-017-2094-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/04/2017] [Indexed: 11/27/2022]
Abstract
This paper vividly indicates that steady state as well as time-resolved fluorescence techniques can serve as highly sensitive monitors to explore the interactions of 5,7-dimethoxy-2,3,4,9-tetrahydro-1H-carbazol-1-one with model transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA). Besides these, we have used fluorescence anisotropy study to assess the degree of restrictions imparted by the micro-environments of serum albumins. Again, to speculate the triplet excited state interaction between such fluorophore and albumin proteins (BSA& HSA), laser flash-photolysis experiments have been carried out. Molecular docking experiments have also been performed to support the conclusions obtained from steady state experiments.
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Affiliation(s)
- Amrit Krishna Mitra
- Department of Chemistry, Government General Degree College, Singur, Hooghly, West Bengal, Pin:712409, India
| | - Abhishek Sau
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India
| | - Uttam Pal
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India
| | - Chandan Saha
- Department of Clinical and Experimental Pharmacology, School of Tropical Medicine, Kolkata, 700073, India
| | - Samita Basu
- Chemical Sciences Division, Saha Institute of Nuclear Physics, Kolkata, 700064, India.
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11
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Ishtikhar M, Khan A, Chang CK, Lin LTW, Wang SSS, Khan RH. Effect of guanidine hydrochloride and urea on the interaction of 6-thioguanine with human serum albumin: a spectroscopic and molecular dynamics based study. J Biomol Struct Dyn 2016. [DOI: 10.1080/07391102.2015.1054433] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Mohd Ishtikhar
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Anam Khan
- Faculty of Engineering, Department of Bioengineering, Integral University, Lucknow 226026, India
| | - Chih-Kai Chang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Lilian Tsai-Wei Lin
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Steven S.-S. Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
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12
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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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13
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Wang YQ, Zhang HM, Cao J. Exploring the interactions of decabrominateddiphenyl ether and tetrabromobisphenol A with human serum albumin. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 38:595-606. [PMID: 25194328 DOI: 10.1016/j.etap.2014.08.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 06/03/2023]
Abstract
Decabrominateddiphenyl ether (deca-BDE) and tetrabromobisphenol A (TBBPA) are known as brominated flame-retardants, which are commonly found in the environment. The binding mechanisms of deca-BDE and TBBPA with human serum albumin (HSA) are still unknown. In this report, the interactions of deca-BDE and TBBPA with HSA were investigated using different spectroscopic methods and molecular modeling. The experimental results indicated the formation of complexes between deca-BDE/TBBPA and HSA with different affinity. These interactions affected the secondary structure of HSA. Thermodynamic investigations revealed that hydrophobic forces mainly drove the binding interactions of deca-BDE/TBBPA with HSA. For TBBPA, hydrogen-bonding interactions were also involved in the binding process of TBBPA with HSA. According to the analysis of experimental and theoretical data, we concluded that the binding site of deca-BDE to HSA located in the subdomain IB, while TBBPA was near to subdomain IIA and Trp-214. The binding interactions of deca-BDE and TBBPA with the most prominent carrier protein in the human circulatory system could influence mechanisms of their biochemical processes. Thus, these binding interactions can play central roles in studying the distribution and toxicity mechanisms of brominated flame-retardants.
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Affiliation(s)
- Yan-Qing Wang
- Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
| | - Hong-Mei Zhang
- Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China
| | - Jian Cao
- Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China
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Antidepressant Fluoxetine Modulates the In Vitro Inhibitory Activity of Buffalo Brain Cystatin: A Thermodynamic Study Using UV and Fluorescence Techniques. BIOTECHNOLOGY RESEARCH INTERNATIONAL 2014; 2014:319397. [PMID: 25170426 PMCID: PMC4131466 DOI: 10.1155/2014/319397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 04/29/2014] [Accepted: 05/06/2014] [Indexed: 11/18/2022]
Abstract
Cystatins constitute a superfamily of homologous proteins. The major role of cystatins is to regulate the unwanted proteolysis and to protect the organism against endogenous proteases released from lysosomes, invading microorganisms and parasites that use cysteine proteases to enter the body. Imbalance in regulation of proteolytic activity may lead to a wide range of human diseases. An enormous progress has been made in understanding of protein degradation process under normal and pathological conditions; infact proteases are now clearly viewed as important drug targets. Fluoxetine a selective serotonin reuptake inhibitor (SSRI) is an antidepressant. It is used to treat major depressive disorders. In the present study binding of fluoxetine to cystatin was studied by UV and fluorescence quenching technique. Intrinsic fluorescence of fluoxetine complexed with purified buffalo brain cystatin (BC) was measured by selectively exciting the tryptophan residues. Gradual quenching was observed on complex formation. When cystatin was added to fluoxetine solutions at a molar ratio of 1 : 0.5, it not only quenched more than half of its fluorescence but also reduced the activity of cystatin. Stern-Volmer plots obtained from experiments carried out at 25(°)C showed the quenching of fluorescence to be a collisional phenomenon. Our results suggest the prime binding site for fluoxetine on BC to be at or near tryptophan residues. Fluoxetine quenched the fluorescence by a static process, which specifically indicates the formation of a complex.
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15
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Del Giudice A, Leggio C, Balasco N, Galantini L, Pavel NV. Ibuprofen and Propofol Cobinding Effect on Human Serum Albumin Unfolding in Urea. J Phys Chem B 2014; 118:10043-51. [DOI: 10.1021/jp504280n] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Alessandra Del Giudice
- Dipartimento
di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy
| | - Claudia Leggio
- Dipartimento
di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy
| | - Nicole Balasco
- Dipartimento
di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy
| | - Luciano Galantini
- Dipartimento
di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy
| | - Nicolae V. Pavel
- Dipartimento
di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy
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16
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Jiang N, Yang C, Dong X, Sun X, Zhang D, Liu C. An ESIPT fluorescent probe sensitive to protein α-helix structures. Org Biomol Chem 2014; 12:5250-9. [DOI: 10.1039/c4ob00405a] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A benzazole derivative,1, was observed to undergo the excited-state intramolecular proton transfer (ESIPT) process with α-helical proteins. The cell images showed a difference in the staining of normal and cancerous prostate cells by1, which might be due to the different membrane protein levels.
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Affiliation(s)
- Nan Jiang
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
| | - Chanli Yang
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
| | - Xiongwei Dong
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
| | - Xianglang Sun
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
| | - Dan Zhang
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
| | - Changlin Liu
- Key Laboratory of Pesticide & Chemical Biology
- Ministry of Education
- School of Chemistry
- Central China Normal University
- Chemistry Building
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17
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Singha Roy A, Dinda AK, Chaudhury S, Dasgupta S. Binding of antioxidant flavonol morin to the native state of bovine serum albumin: Effects of urea and metal ions on the binding. JOURNAL OF LUMINESCENCE 2014; 145:741-751. [DOI: 10.1016/j.jlumin.2013.08.054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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18
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Chaudhary A, Gupta A, Khan S, Nandi CK. Morphological effect of gold nanoparticles on the adsorption of bovine serum albumin. Phys Chem Chem Phys 2014; 16:20471-82. [DOI: 10.1039/c4cp01515k] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of morphology and surface chemistry of gold nanoparticles in the adsorption of bovine serum albumin.
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Affiliation(s)
- Abhishek Chaudhary
- School of Basic Sciences
- Indian Institute of Technology Mandi
- Himachal Pradesh, India-175001
| | - Abhishek Gupta
- School of Basic Sciences
- Indian Institute of Technology Mandi
- Himachal Pradesh, India-175001
| | - Syamantak Khan
- School of Basic Sciences
- Indian Institute of Technology Mandi
- Himachal Pradesh, India-175001
| | - Chayan Kanti Nandi
- School of Basic Sciences
- Indian Institute of Technology Mandi
- Himachal Pradesh, India-175001
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Nag M, Bera K, Chakraborty S, Basak S. Sensing of hydrophobic cavity of serum albumin by an adenosine analogue: Fluorescence correlation and ensemble spectroscopic studies. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2013; 127:202-11. [DOI: 10.1016/j.jphotobiol.2013.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 08/14/2013] [Accepted: 08/19/2013] [Indexed: 01/09/2023]
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20
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Majumdar T, Bhowmik D, Kundu A, Dasmandal S, Mahapatra A. The effect of serum albumin, surfactant and their mixture on the reduction of a cobalt(III) complex by ascorbic acid. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Sen P, Khan MM, Equbal A, Ahmad E, Khan RH. At very low concentrations known chaotropes act as kosmotropes for the N and B isoforms of human serum albumin. Biochem Cell Biol 2013; 91:72-8. [DOI: 10.1139/bcb-2012-0035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Very few studies have been done to understand the effect of millimolar concentrations of chaotropes on protein structure. In our previous study we observed that the secondary and tertiary structure of human serum albumin (HSA) increases in the presence of 5 mmol/L urea. Micelle formation in amphoteric detergents increases in the presence of equivalent concentrations of urea. Here, we observed a significant increase in the secondary and tertiary structure of HSA. Interestingly, guanidine hydrochloride, another chaotropic agent, also shows a similar effect. Our results show electrostatic interaction may play a role in neutral to basic transition in HSA. This study further supports the claim that at millimolar concentrations the chaotropes may act as kosmotropes for proteins.
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Affiliation(s)
- Priyankar Sen
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
- P.G. Department of Biotechnology, Utkal University, Bhubaneswar 751004, India
| | - Mohd Moin Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Asif Equbal
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Ejaz Ahmad
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
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Fluorescence modulation and associative behavior of lumazine in hydrophobic domain of micelles and bovine serum albumin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2013; 121:37-45. [DOI: 10.1016/j.jphotobiol.2013.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/13/2013] [Accepted: 02/13/2013] [Indexed: 11/21/2022]
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Kamtekar N, Pandey A, Agrawal N, Pissurlenkar RRS, Borana M, Ahmad B. Interaction of multimicrobial synthetic inhibitor 1,2-bis(2-benzimidazolyl)-1,2-ethanediol with serum albumin: spectroscopic and computational studies. PLoS One 2013; 8:e53499. [PMID: 23308237 PMCID: PMC3537617 DOI: 10.1371/journal.pone.0053499] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 11/30/2012] [Indexed: 02/02/2023] Open
Abstract
The molecule, 1,2-Bis(2-benzimidazolyl)-1,2-ethanediol (BBE) is known to act as a selective inhibitor of poliovirus, rhinovirus, Candida albicans, several bacterial species, and is easily synthesized by Phillips reaction. The interaction of BBE with BSA and the effects of its binding on the conformation and unfolding/refolding pathways of the protein were investigated using multispectroscopic techniques and molecular modeling. The binding studies indicate that BSA has one high affinity BBE binding site with association constant 6.02±0.05×10(4) M(-1) at 298 K. By measuring binding at different temperatures, we determined the changes in enthalpy (ΔH = -15.13±2.15 kJ mol(-1)), entropy (ΔS = 40.87±7.25 J mol(-1) K(-1)) and free energy (ΔG( = )26.78±1.02) of interaction, which indicate that the binding was spontaneous and both enthalpically and entropically driven. Based on molecular modeling and thermodynamic parameters, we proposed that the complex formation involved mainly hydrophilic interaction such as hydrogen bonding between hydroxyl groups of ethane-1,2-diol fragment with Tyr410 and benzimidazole sp(2) nitrogen atom with Ser488 and hydrophobic interaction between phenyl ring of one benzimidazole of the ligand and hydrophobic residues namely, Ile387, Cys391, Phe402, Val432 and Cys437. The sequential unfolding mechanism of BSA, site-specific marker displacement experiments and molecular modeling showed that the molecule preferably binds in subdomain IIIA. The BBE binding to BSA was found to cause both secondary and tertiary structural alterations in the protein as studied by intrinsic fluorescence, near-UV and far-UV circular dichroism results. The unfolding/refolding study showed that BBE stabilized native to intermediate states (N⇌I) transition of the protein by ∼2 kJ mol(-1) without affecting the intermediate to unfolded states (I⇌U) transition and general mechanism of unfolding of BSA.
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Affiliation(s)
- Nayana Kamtekar
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai, India
| | - Anita Pandey
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai, India
| | - Neeraj Agrawal
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai, India
| | | | - Mohanish Borana
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai, India
| | - Basir Ahmad
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai, India
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Singha Roy A, Pandey NK, Dasgupta S. Preferential binding of fisetin to the native state of bovine serum albumin: spectroscopic and docking studies. Mol Biol Rep 2013; 40:3239-53. [PMID: 23277393 DOI: 10.1007/s11033-012-2399-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 12/17/2012] [Indexed: 11/25/2022]
Abstract
We have investigated the binding of the biologically important flavonoid fisetin with the carrier protein bovine serum albumin using multi-spectroscopic and molecular docking methods. The binding constants were found to be in the order of 10(4) M(-1) and the number of binding sites was determined as one. MALDI-TOF analyses showed that one fisetin molecule binds to a single bovine serum albumin (BSA) molecule which is also supported by fluorescence quenching studies. The negative Gibbs free energy change (∆G°) values point to a spontaneous binding process which occurs through the presence of electrostatic forces with hydrophobic association that results in a positive entropy change (+51.69 ± 1.18 J mol(-1) K(-1)). The unfolding and refolding of BSA in urea have been studied in absence and presence of fisetin using steady-state fluorescence and lifetime measurements. Urea denaturation studies indicate that fisetin is gradually released from its binding site on the protein. In the absence of urea, an increase in temperature that causes denaturation of the protein results in the release of fisetin from its bound state indicating that fisetin binds only to the native state of the protein. The circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopic studies showed an increase in % α-helix content of BSA after binding with fisetin. Site marker displacement studies in accordance with the molecular docking results suggested that fisetin binds in close proximity of the hydrophobic cavity in site 1 (subdomain IIA) of the protein. The PEARLS (Program of Energetic Analysis of Receptor Ligand System) has been used to estimate the interaction energy of fisetin with BSA and the results are in good correlation with the experimental findings.
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Affiliation(s)
- Atanu Singha Roy
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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25
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Mandal HK, Kundu A, Balti S, Mahapatra A. Kinetic investigation on the oxidation of tris(1,10-phenanthroline)iron(II) by oxone: The effect of BSA–SDS interaction. J Colloid Interface Sci 2012; 378:110-7. [DOI: 10.1016/j.jcis.2012.04.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 04/05/2012] [Accepted: 04/07/2012] [Indexed: 10/28/2022]
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26
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Norberto DR, Vieira JM, de Souza AR, Bispo JAC, Bonafe CFS. Pressure- and Urea-Induced Denaturation of Bovine Serum Albumin: Considerations about Protein Heterogeneity. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojbiphy.2012.21002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Investigations on the interactions of aurintricarboxylic acid with bovine serum albumin: Steady state/time resolved spectroscopic and docking studies. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 102:11-9. [PMID: 20863713 DOI: 10.1016/j.jphotobiol.2010.08.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 07/26/2010] [Accepted: 08/30/2010] [Indexed: 11/21/2022]
Abstract
In this paper, the nature of the interactions between bovine serum albumin (BSA) and aurintricarboxylic acid (ATA) has been investigated by measuring steady state and time-resolved fluorescence, circular dichroism (CD), FT-IR and fluorescence anisotropy in protein environment under physiological conditions. From the analysis of the steady state and time-resolved fluorescence quenching of BSA in aqueous solution in presence of ATA it has been inferred that the nature of the quenching originates from the combined effect of static and dynamic modes. From the determination of the thermodynamic parameters obtained from temperature-dependent changes in K(b) (binding constant) it was apparent that the combined effect of hydrophobic association and electrostatic attraction is responsible for the interaction of ATA with BSA. The effect of ATA on the conformation of BSA has been examined by analyzing CD spectrum. Though the observed results demonstrate some conformational changes in BSA in presence of ATA but the secondary structure of BSA, predominantly of α-helix, is found to retain its identity. Molecular docking of ATA with BSA also indicates that ATA docks through hydrophobic interaction.
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28
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Photophysics of norharmane in solution phase: From homogeneous to microheterogeneous environments. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2010. [DOI: 10.1016/j.jphotochemrev.2010.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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29
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Paul BK, Samanta A, Guchhait N. Exploring Hydrophobic Subdomain IIA of the Protein Bovine Serum Albumin in the Native, Intermediate, Unfolded, and Refolded States by a Small Fluorescence Molecular Reporter. J Phys Chem B 2010; 114:6183-96. [DOI: 10.1021/jp100004t] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Bijan Kumar Paul
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Calcutta 700009, India
| | - Anuva Samanta
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Calcutta 700009, India
| | - Nikhil Guchhait
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Calcutta 700009, India
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Sen P, Iqbal MA, Fatima S, Khan RH. Methyl cyanide induces α to β transition and aggregation at high concentrations in E-state of human serum albumin. BIOCHEMISTRY (MOSCOW) 2010; 75:367-74. [DOI: 10.1134/s0006297910030132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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31
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Varshney A, Sen P, Ahmad E, Rehan M, Subbarao N, Khan RH. Ligand binding strategies of human serum albumin: how can the cargo be utilized? Chirality 2010; 22:77-87. [PMID: 19319989 DOI: 10.1002/chir.20709] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human serum albumin (HSA), being the most abundant carrier protein in blood and a modern day clinical tool for drug delivery, attracts high attention among biologists. Hence, its unfolding/refolding strategies and exogenous/endogenous ligand binding preference are of immense use in therapeutics and clinical biochemistry. Among its fellow proteins albumin is known to carry almost every small molecule. Thus, it is a potential contender for being a molecular cargo/or nanovehicle for clinical, biophysical and industrial purposes. Nonetheless, its structure and function are largely regulated by various chemical and physical factors to accommodate HSA to its functional purpose. This multifunctional protein also possesses enzymatic properties which may be used to convert prodrugs to active therapeutics. This review aims to highlight current overview on the binding strategies of protein to various ligands that may be expected to lead to significant clinical applications.
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Affiliation(s)
- Ankita Varshney
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
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32
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Sen P, Fatima S, Ahmad B, Khan RH. Interactions of thioflavin T with serum albumins: spectroscopic analyses. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:94-9. [PMID: 19502106 DOI: 10.1016/j.saa.2009.05.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 04/23/2009] [Accepted: 05/13/2009] [Indexed: 05/22/2023]
Abstract
The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant (K) for HSA was found to be 9.9 x 10(4)M(-1), 4.3 x 10(4)M(-1) for RSA, 1.07 x 10(4)M(-1) for PSA and 0.3 x 10(4)M(-1) for BSA and the number of binding sites (n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. DeltaG(binding), DeltaH and DeltaS were calculated to be -28.46 kJ mol(-1), -3.50 kJ mol(-1) and 81.04 JK(-1)mol(-1), respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.
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Affiliation(s)
- Priyankar Sen
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
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33
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Leggio C, Galantini L, Konarev PV, Pavel NV. Urea-Induced Denaturation Process on Defatted Human Serum Albumin and in the Presence of Palmitic Acid. J Phys Chem B 2009; 113:12590-602. [DOI: 10.1021/jp904330v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Claudia Leggio
- Dipartimento di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy, INFM CRS-SOFT, c/o Sapienza Università di Roma, Roma, Italy, and Hamburg Outstation, European Molecular Biology Laboratory, D-22603 Hamburg, Germany
| | - Luciano Galantini
- Dipartimento di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy, INFM CRS-SOFT, c/o Sapienza Università di Roma, Roma, Italy, and Hamburg Outstation, European Molecular Biology Laboratory, D-22603 Hamburg, Germany
| | - Peter V. Konarev
- Dipartimento di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy, INFM CRS-SOFT, c/o Sapienza Università di Roma, Roma, Italy, and Hamburg Outstation, European Molecular Biology Laboratory, D-22603 Hamburg, Germany
| | - Nicolae V. Pavel
- Dipartimento di Chimica, Sapienza Università di Roma, P.O. Box 34-Roma 62, Piazzale A. Moro 5, I-00185 Roma, Italy, INFM CRS-SOFT, c/o Sapienza Università di Roma, Roma, Italy, and Hamburg Outstation, European Molecular Biology Laboratory, D-22603 Hamburg, Germany
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34
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Ghosh S, Guchhait N. Chemically Induced Unfolding of Bovine Serum Albumin by Urea and Sodium Dodecyl Sulfate: A Spectral Study with the Polarity-Sensitive Charge-Transfer Fluorescent Probe (E)-3-(4-Methylaminophenyl)acrylic Acid Methyl Ester. Chemphyschem 2009; 10:1664-71. [DOI: 10.1002/cphc.200900161] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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35
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Zhang YZ, Xiang X, Mei P, Dai J, Zhang LL, Liu Y. Spectroscopic studies on the interaction of Congo Red with bovine serum albumin. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 72:907-914. [PMID: 19155189 DOI: 10.1016/j.saa.2008.12.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 12/04/2008] [Accepted: 12/09/2008] [Indexed: 05/27/2023]
Abstract
The binding interaction of Congo Red (CGR) with bovine serum albumin (BSA) was investigated by spectroscopic techniques including fluorescence spectroscopy, UV-vis absorption, and circular dichroism (CD) spectroscopy under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by CGR was the result of the formation of a BSA-CGR complex, and the corresponding binding constants (K(a)) at the four different temperatures (292, 298, 304, and 310K) were obtained according to the modified Stern-Volmer equation. The thermodynamic parameters DeltaH and DeltaS were calculated to be -12.67kJmol(-1) and 58.60Jmol(-1)K(-1), respectively, which suggested that both hydrophobic force and hydrogen bond played major roles in stabilizing the BSA-CGR complex. Site marker competitive experiments showed that the binding of CGR to BSA primarily took place in site I of BSA. The distance r between CGR (acceptor) and tryptophan residues of BSA (donor) was calculated to be 3.89nm based on Förster's non-radioactive energy transfer theory. The conformational investigation showed that the presence of CGR resulted in the change of BSA secondary structure and induced the slight unfolding of the polypeptides of protein, which confirmed some micro-environmental and conformational changes of BSA molecules.
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Affiliation(s)
- Ye-Zhong Zhang
- Department of Chemistry, Yangtze University, Jingzhou, Hubei, PR China
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Juárez J, Taboada P, Mosquera V. Existence of different structural intermediates on the fibrillation pathway of human serum albumin. Biophys J 2009; 96:2353-70. [PMID: 19289061 PMCID: PMC2907680 DOI: 10.1016/j.bpj.2008.12.3901] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 11/18/2008] [Accepted: 12/01/2008] [Indexed: 10/21/2022] Open
Abstract
The fibrillation propensity of the multidomain protein human serum albumin (HSA) was analyzed under different solution conditions. The aggregation kinetics, protein conformational changes upon self-assembly, and structure of the different intermediates on the fibrillation pathway were determined by means of thioflavin T (ThT) fluorescence and Congo Red absorbance; far- and near-ultraviolet circular dichroism; tryptophan fluorescence; Fourier transform infrared spectroscopy; x-ray diffraction; and transmission electron, scanning electron, atomic force, and microscopies. HSA fibrillation extends over several days of incubation without the presence of a lag phase, except for HSA samples incubated at acidic pH and room temperature in the absence of electrolyte. The absence of a lag phase occurs if the initial aggregation is a downhill process that does not require a highly organized and unstable nucleus. The fibrillation process is accompanied by a progressive increase in the beta-sheet (up to 26%) and unordered conformation at the expense of alpha-helical conformation, as revealed by ThT fluorescence and circular dichroism and Fourier transform infrared spectroscopies, but changes in the secondary structure contents depend on solution conditions. These changes also involve the presence of different structural intermediates in the aggregation pathway, such as oligomeric clusters (globules), bead-like structures, and ring-shaped aggregates. We suggest that fibril formation may take place through the role of association-competent oligomeric intermediates, resulting in a kinetic pathway via clustering of these oligomeric species to yield protofibrils and then fibrils. The resultant fibrils are elongated but curly, and differ in length depending on solution conditions. Under acidic conditions, circular fibrils are commonly observed if the fibrils are sufficiently flexible and long enough for the ends to find themselves regularly in close proximity to each other. These fibrils can be formed by an antiparallel arrangement of beta-strands forming the beta-sheet structure of the HSA fibrils as the most probable configuration. Very long incubation times lead to a more complex morphological variability of amyloid mature fibrils (i.e., long straight fibrils, flat-ribbon structures, laterally connected fibers, etc.). We also observed that mature straight fibrils can also grow by protein oligomers tending to align within the immediate vicinity of the fibers. This filament + monomers/oligomers scenario is an alternative pathway to the otherwise dominant filament + filament manner of the protein fibril's lateral growth. Conformational preferences for a certain pathway to become active may exist, and the influence of environmental conditions such as pH, temperature, and salt must be considered.
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Affiliation(s)
| | - Pablo Taboada
- Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
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Singh RB, Mahanta S, Bagchi A, Guchhait N. Interaction of human serum albumin with charge transfer probe ethyl ester of N,N-dimethylamino naphthyl acrylic acid: An extrinsic fluorescence probe for studying protein micro-environment. Photochem Photobiol Sci 2009; 8:101-10. [DOI: 10.1039/b814050b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Santos JLR, Aparicio R, Joekes I, Silva JL, Bispo JAC, Bonafe CFS. Different urea stoichiometries between the dissociation and denaturation of tobacco mosaic virus as probed by hydrostatic pressure. Biophys Chem 2008; 134:214-24. [PMID: 18367310 DOI: 10.1016/j.bpc.2008.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 02/14/2008] [Accepted: 02/17/2008] [Indexed: 10/22/2022]
Abstract
Viruses are very efficient self-assembly structures, but little is understood about the thermodynamics governing their directed assembly. At higher levels of pressure or when pressure is combined with urea, denaturation occurs. For a better understanding of such processes, we investigated the apparent thermodynamic parameters of dissociation and denaturation by assuming a steady-state condition. These processes can be measured considering the decrease of light scattering of a viral solution due to the dissociation process, and the red shift of the fluorescence emission spectra, that occurs with the denaturation process. We determined the apparent urea stoichiometry considering the equilibrium reaction of TMV dissociation and subunit denaturation, which furnished, respectively, 1.53 and 11.1 mol of urea/mol of TMV subunit. The denaturation and dissociation conditions were arrived in a near reversible pathway, allowing the determination of thermodynamic parameters. Gel filtration HPLC, electron microscopy and circular dichroism confirmed the dissociation and denaturation processes. Based on spectroscopic results from earlier papers, the calculation of the apparent urea stoichiometry of dissociation and denaturation of several other viruses resulted in similar values, suggesting a similar virus-urea interaction among these systems.
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Affiliation(s)
- Jose L R Santos
- Laboratório de Termodinâmica de Proteínas, Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, CP 6109, Brazil
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Greige-Gerges H, Diab Y, Farah J, Magdalou J, Haddad C, Ouaini N. Ferutinin stability in human plasma and interaction with human serum albumin. Biopharm Drug Dispos 2008; 29:83-9. [DOI: 10.1002/bdd.589] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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40
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Leggio C, Galantini L, Pavel NV. About the albumin structure in solution: cigar Expanded form versus heart Normal shape. Phys Chem Chem Phys 2008; 10:6741-50. [DOI: 10.1039/b808938h] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Effect of solvation on the structure conformation of human serum albumin in aqueous–alcohol mixed solvents. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.07.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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42
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Mallick A, Haldar B, Chattopadhyay N. Spectroscopic investigation on the interaction of ICT probe 3-acetyl-4-oxo-6,7-dihydro-12H Indolo-[2,3-a] quinolizine with serum albumins. J Phys Chem B 2007; 109:14683-90. [PMID: 16852853 DOI: 10.1021/jp051367z] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interaction of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ), a biologically active molecule, with model transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA) have been studied using steady state and picosecond time-resolved fluorescence and fluorescence anisotropy. The polarity dependent intramolecular charge transfer (ICT) process is responsible for the remarkable sensitivity of this biological fluorophore to the protein environments. The CT fluorescence exhibits appreciable hypsochromic shift along with an enhancement in the fluorescence yield, fluorescence anisotropy (r) and fluorescence lifetime upon binding with the proteins. The reduction in the rate of ICT within the hydrophobic interior of albumins leads to an increase in the fluorescence yield and lifetime. Marked increase in the fluorescence anisotropy indicates that the probe molecule is located in a motionally constrained environment within the proteins. Micropolarities in the two proteinous environments have been determined following the polarity sensitivity of the CT emission. Addition of urea to the protein-bound systems leads to a reduction in the fluorescence anisotropy indicating the denaturation of the proteins. Polarity measurements and fluorescence resonance energy transfer (FRET) studies throw light in assessing the location of the fluorophore within the two proteinous media.
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Affiliation(s)
- Arabinda Mallick
- Department of Chemistry, Jadavpur University, Calcutta-700 032, India
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Cheema MA, Taboada P, Barbosa S, Castro E, Siddiq M, Mosquera V. Energetics and Conformational Changes upon Complexation of a Phenothiazine Drug with Human Serum Albumin. Biomacromolecules 2007; 8:2576-85. [PMID: 17592874 DOI: 10.1021/bm070354j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interactions and complexation process of the amphiphilic phenothiazine fluphenazine hydrochloride with human serum albumin in aqueous buffered solutions of pH 3.0 and 7.4 have been examined by zeta-potential, isothermal titration calorimetry (ITC), UV-vis spectroscopy, and dynamic light scattering (DLS) techniques with the aim of analyzing the effect of hydrophobic and electrostatic forces on the complexation process and the alteration of protein conformation upon binding. Thus, the energetics and stoichiometry of the binding process were derived from ITC data. The enthalpies of binding obtained are small and exothermic, so the Gibbs energies of binding are dominated by large increases in entropy, consistent with hydrophobic interactions at a acidic pH. However, at physiological pH, binding to the first class of binding sites is dominated by an enthalpic contribution due to the existence of electrostatic interactions and probably some hydrogen bonding. Binding isotherms were obtained from microcalorimetric data by using a theoretical model based on the Langmuir isotherm. zeta-Potential data showed a reversal in the sign of the protein charge at pH 7.4, as a consequence of the binding of the drug to the protein. Gibbs energies of drug binding per mole of drug were also derived from zeta-potential data. On the other hand, binding of the phenothiazine that causes a conformational transition on the protein structure was followed as a function of drug concentration using UV-vis spectroscopy, and the data were analyzed to obtain the Gibbs energy of the transition in water (deltaG(degree)w) and in a hydrophobic environment (deltaG(degree)hc). Finally, the population distribution of the different species in solution and the size of the complexes were analyzed through dynamic light scattering. The existence of an aggregation process of drug/protein complexes, as a consequence of the expanded structure of the protein induced by the drug and subsequent further binding, is in agreement with ITC data. In addition, detection of drug aggregates at concentrations below the drug critical micelle concentration was also detected by this technique.
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Affiliation(s)
- Mohammad Arif Cheema
- Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, E-15782, Santiago de Compostela, Spain
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Chakrabarty A, Mallick A, Haldar B, Das P, Chattopadhyay N. Binding Interaction of a Biological Photosensitizer with Serum Albumins: A Biophysical Study. Biomacromolecules 2007; 8:920-7. [PMID: 17315924 DOI: 10.1021/bm061084s] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A photophysical study on the binding interaction of an efficient cancer cell photosensitizer, norharmane (NHM), with model transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA), has been performed using a combination of steady-state and time-resolved fluorescence techniques. The emission profile undergoes a remarkable change upon addition of the proteins to the buffered aqueous solution of the photosensitizer. The polarity-dependent prototropic transformation is responsible for the remarkable sensitivity of this biological fluorophore to the protein environments. A marked increase in the fluorescence anisotropy in the proteinous environments indicates that the albumin proteins introduce motional restriction on the drug molecule. Light has been thrown on the denaturing action of urea on the probe-bound protein. The probable binding site of the drug in proteins has also been assessed from the combination of denaturation study, micropolarity measurement, and fluorescence resonance energy transfer (FRET) study. The present study suggests that the stability of serum albumins is enhanced upon binding with the drug.
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Affiliation(s)
- Alok Chakrabarty
- Department of Chemistry, Jadavpur University, Calcutta-700 032, India
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Greige-Gerges H, Abou Khalil R, Chahine R, Haddad C, Harb W, Ouaini N. Effect of cucurbitacins on bilirubin-albumin binding in human plasma. Life Sci 2006; 80:579-85. [PMID: 17097690 DOI: 10.1016/j.lfs.2006.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Revised: 10/03/2006] [Accepted: 10/10/2006] [Indexed: 11/18/2022]
Abstract
The aim of this study is to investigate the effect of three cucurbitacins (Cuc) E, D and I on the bilirubin-albumin binding, both in human serum albumin (HSA) and in plasma. Bilirubin-HSA solution and plasma free of cucurbitacins were prepared as well as others containing serial concentrations of cucurbitacins. The concentration of unbound bilirubin was determined in bilirubin-HSA solution and the direct and total bilirubin concentrations were measured in plasma (with normal or elevated bilirubinemia) by Jendrassik and Grof method. In the conditions we adopted Cuc E and D (to a lesser extent), decreased the levels of unbound bilirubin in bilirubin-HSA solution and decreased direct bilirubin concentration and total bilirubin concentration in plasma in a dose-dependent manner while Cuc I had no effect. The effect of Cuc is related to the presence of native HSA. Thus, when albumin was absent or has been denatured by heating or by urea, Cuc E did not modify bilirubin levels, suggesting that the native structure of albumin is essential for such activity. The interaction of HSA with Cuc E was investigated by fluorescence spectroscopy. Cuc E increased the intrinsic fluorescence of the protein and the magnitude of fluorescence intensity of bilirubin-albumin complex. We concluded that Cuc E and D produced a rearrangement in the structure of albumin, particularly in the domain-II, resulting in an increase in the binding of bilirubin to albumin regardless to whether it's conjugated to glucuronic acid or unconjugated.
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Affiliation(s)
- H Greige-Gerges
- Biochemistry Department, Holy Spirit University of Kaslik, B.P. 446 Jounieh, Lebanon.
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Ahmad B, Parveen S, Khan RH. Effect of Albumin Conformation on the Binding of Ciprofloxacin to Human Serum Albumin: A Novel Approach Directly Assigning Binding Site. Biomacromolecules 2006; 7:1350-6. [PMID: 16602760 DOI: 10.1021/bm050996b] [Citation(s) in RCA: 260] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human serum albumin (HSA) is known to exist as N (pH approximately 7), B (pH approximately 9), and F (pH approximately 3.5) isomeric forms and an equilibrium intermediate state (I) accumulate in the urea induced unfolding pathway of HSA around 4.8-5.2 M urea concentrations. These states displayed characteristic structure and functions. To elucidate the ciprofloxacin (CFX) binding behavior of HSA, the binding of ciprofloxacin with these conformational states of human serum albumin (HSA) has been investigated by fluorescence spectroscopy. The binding constant (K) for N, B, F, and I conformation of HSA were 6.92 x 10(5), 3.87 x 10(5), 4.06 x 10(5), and 2.7 x 10(5) M(-1) and the number of binding sites (n) were 1.26,1.21, 1.16, and 1.19, respectively. The standard free energy changes (DeltaGbinding(0)) of interaction were found to be -33.3 (N isomer), -31.8 (B isomer), -32 (F isomer), and -30.0 kJ mol(-1) respectively. By using unfolding pathway of HSA, domain II of HSA has been assigned to possess binding site of ciprofloxacin. Plausible correlation between stability of CFX-N and CFX-B complexes and drug distribution have been discussed. At plasma concentration of HSA fraction of free CFX, which contributes potential to its rate of transport across cell membrane, was found to be approximately 80% more for B isomers compared to N isomers of HSA. The conformational changes in two physiologically important isomers of HSA (N and B isomers) upon ciprofloxacin binding were evaluated by measuring far, near-UV CD, and fluorescence properties of the CFX-HSA complex.
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Affiliation(s)
- Basir Ahmad
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh U.P., India 202002
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Ahmad B, Ahmed MZ, Haq SK, Khan RH. Guanidine hydrochloride denaturation of human serum albumin originates by local unfolding of some stable loops in domain III. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1750:93-102. [PMID: 15890566 DOI: 10.1016/j.bbapap.2005.04.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 04/01/2005] [Accepted: 04/04/2005] [Indexed: 11/15/2022]
Abstract
The effect of guanidine hydrochloride (GnHCl) on the global stability of human serum albumin (HSA) has been studied by fluorescence and circular dichroism spectroscopic measurements. The differential stability of native conformation of three HSA domains were explored by using domain-specific ligands, hemin (domain I), chloroform (domain II), bilirubin (at domain I/domain II interface) and diazepam (domain III). GnHCl induced unfolding transition curves as monitored by probes for secondary and tertiary structures were cooperative but noncoincidental. A strong ANS binding to the protein was observed around 1.8 M GnHCl, suggesting existence of intermediate states in the unfolding pathway of HSA. A gradual decrease (in the GnHCl concentration range 0.0-1.8 M) in the binding of diazepam indicates that domain III is the most labile to GnHCl denaturation. A significant increase in the binding of bilirubin up to 1.4 M GnHCl and decrease thereafter leading to complete abolishment of bilirubin binding at around 2.0 M GnHCl suggest favorable rearrangement and separation of domains I and II at 1.4 and 2.0 M GnHCl concentration, respectively. Above 1.6 M GnHCl, decrease of the binding of hemin, a ligand for domain I, chloroform, which binds in domain II and lone tryptophanyl fluorescence (Trp-214 located in domain II) indicate that at higher concentration of GnHCl domains I and II start unfolding simultaneously but the stability of domain I (7.4 Kcal/mol) is much more than domain II (4.3 Kcal/mol). A pictorial model for the unfolding of HSA domains, consistent with all these results, has been formulated, suggesting that domain III is the most labile followed by domain II while domain I is the most stable. A molten globule like state of domain III around 1.8 M GnHCl has also been identified and characterized.
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Affiliation(s)
- Basir Ahmad
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh-202002, India
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Ahmad B, Khan RH. Urea induced unfolding of F isomer of human serum albumin: A case study using multiple probes. Arch Biochem Biophys 2005; 437:159-67. [PMID: 15929204 DOI: 10.1016/j.abb.2005.03.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The human serum albumin is known to undergo N <==> F (neutral to fast moving) isomerization between pH 7 and 3.5. The N < ==> F isomerization involves unfolding and separation of domain III from rest of the molecule. The urea denaturation of N isomer of HSA shows two step three state transition with accumulation of an intermediate state around 4.8-5.2 M urea concentration. While urea induced unfolding transition of F isomer of HSA does not show the intermediate state observed during unfolding of N isomer. Therefore, it provides direct evidence that the formation of intermediate in the unfolding transition of HSA involves unfolding of domain III. Although urea induced unfolding of F isomer of HSA appears to be an one step process, but no coincidence between the equilibrium transitions monitored by tryptophanyl fluorescence, tyrosyl fluorescence, far-UV CD and near-UV CD spectroscopic techniques provides decisive evidence that unfolding of F isomer of HSA is not a two state process. An intermediate state that retained significant amount of secondary structure but no tertiary structure has been identified (around 4.4 M urea) in the unfolding pathway of F isomer. The emission of Trp-214 (located in domain II) and its mode of quenching by acrylamide and binding of chloroform indicate that unfolding of F isomer start from domain II (from 0.4 M urea). But at higher urea concentration (above 1.6 M) both the domain unfold simultaneously and the protein acquire random coil structure around 8.0 M urea. Further much higher KSV of NATA (17.2) than completely denatured F isomer (5.45) of HSA (8.0 M urea) suggests the existence of residual tertiary contacts within local regions in random coil conformation (probably around lone Trp-214).
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Affiliation(s)
- Basir Ahmad
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
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