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Park HK, Park JH, Lee H, Hong S. Material-Selective Polydopamine Coating in Dimethyl Sulfoxide. ACS APPLIED MATERIALS & INTERFACES 2020; 12:49146-49154. [PMID: 32985875 DOI: 10.1021/acsami.0c11440] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Polydopamine coating is known to be performed in a material-independent manner and has become a popular tool when designing a surface-functionalization strategy of a given material. Studies to improve polydopamine coatings have been reported, aiming to reduce the coating time (by transition metals, oxidants, applied voltages, or microwave irradiation), control surface roughness using catechol derivatives, and vary the ad-layer molecules formed on an underlying polydopamine layer. However, none of the techniques have changed the most important intrinsic property of polydopamine, the surface-independent coating. Currently, no method has been reported to modify this property to create a material-selective 'smart' polydopamine coating. Herein, we report a method with polydopamine to differentiate the chemistry of surfaces. We found that the polydopamine coating was largely inhibited on silicon-containing surfaces such as Si wafers and quartz crystals in a dimethyl sulfoxide (DMSO)/phosphate-buffered saline (PBS) cosolvent, while the coating properties on other materials remained mostly unchanged. Among the various interface bonding mechanisms of coordination, namely, cation-π, π-π stacking, and hydrogen-bonding interactions, the DMSO/PBS cosolvent effectively inhibits hydrogen-bond formation between catechol and SiO2, resulting in surface-selective 'smart' polydopamine coatings. The new polydopamine coating is useful for functionalizing patterned surfaces such as Au patterns on SiO2 substrates. Considering that Si wafer is the most widely used substrate, the surface-selective polydopamine coating technique described herein opens up a new direction in surface functionalization and interface chemistry.
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Affiliation(s)
- Hong K Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji Hun Park
- Department of Science Education, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Haeshin Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Seonki Hong
- Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
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2
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Tom J, Jakubec PJ, Andreas HA. Mechanisms of Enhanced Hemoglobin Electroactivity on Carbon Electrodes upon Exposure to a Water-Miscible Primary Alcohol. Anal Chem 2018; 90:5764-5772. [PMID: 29659245 DOI: 10.1021/acs.analchem.8b00117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Exposing a carbon electrode to hemoglobin (Hb) and alcoholic solvents, such as methanol, ethanol or 1-propanol, drastically changes Hb electroactivity, but until this work, the important underlying mechanisms were unclear. For the first time, we show that these alcohols impact Hb electroactivity via three mechanisms: modification of the carbon surface oxides on the glassy carbon (GC) electrode, Hb film formation, and structural changes to Hb. C1s X-ray photoelectron spectroscopy provided evidence for significant alcohol-induced modification of the carbon surface oxides, and differential pulse voltammetry showed links between these modifications and Hb electroactivity. Spectroscopic ellipsometry showed that Hb films formed during exposure to Hb- and alcohol-containing electrolytes increased in thickness with increasing alcohol content, although film thickness played only a minor role in Hb electroactivity. Alcohol-induced structural changes in Hb are confirmed with UV-visible absorption and fluorescence data, showing that Hb denaturation also was a significant factor in increasing Hb electroactivity. Carbon-surface-oxide modification and Hb denaturation worked in tandem to maximally increase the Hb electroactivity in 60% methanol. While in ethanol and 1-propanol, the significant increases in Hb electroactivity caused by Hb denaturation were offset by an increase in Hb-inhibiting carbon surface oxides. Knowledge of these mechanisms shows the impact of alcohols on both Hb and carbon electrodes, allows for thoughtful design of the Hb-sensing system, is vital for proper analysis of Hb electroactivity in the presence of these alcohols (e.g., when used as binder solvents for immobilizing Hb into films), and provides fundamental understanding of the Hb-carbon interactions.
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Affiliation(s)
- Justin Tom
- Department of Chemistry , Dalhousie University , Halifax , Nova Scotia , Canada B3H 4R2
| | - Philip J Jakubec
- Department of Chemistry , Dalhousie University , Halifax , Nova Scotia , Canada B3H 4R2
| | - Heather A Andreas
- Department of Chemistry , Dalhousie University , Halifax , Nova Scotia , Canada B3H 4R2
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3
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To reveal the nature of interactions of human hemoglobin with gold nanoparticles having two different morphologies (sphere and star-shaped) by using various spectroscopic techniques. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 178:355-366. [DOI: 10.1016/j.jphotobiol.2017.11.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/06/2017] [Accepted: 11/20/2017] [Indexed: 11/19/2022]
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4
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Guo L, Ma X, Yan J, Xu K, Wang Q, Li H. Interaction Behavior Between Niclosamide and Pepsin Determined by Spectroscopic and Docking Methods. J Fluoresc 2015; 25:1681-93. [PMID: 26410777 PMCID: PMC7087788 DOI: 10.1007/s10895-015-1655-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/09/2015] [Indexed: 12/20/2022]
Abstract
The interaction between niclosamide (NIC) and pepsin was investigated using multispectroscopic and molecular docking methods. Binding constant, number of binding sites, and thermodynamic parameters at different temperatures were measured. Results of fluorescence quenching and synchronous fluorescence spectroscopy in combination with three-dimensional fluorescence spectroscopy showed that changes occurred in the microenvironment of tryptophan residues and the molecular conformation of pepsin. Molecular interaction distance and energy-transfer efficiency between pepsin and NIC were determined based on Förster nonradiative energy-transfer mechanism. Furthermore, the binding of NIC inhibited pepsin activity in vitro. All these results indicated that NIC bound to pepsin mainly through hydrophobic interactions and hydrogen bonds at a single binding site. In conclusion, this study provided substantial molecular-level evidence that NIC could induce changes in pepsin structure and conformation.
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Affiliation(s)
- Liuqi Guo
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China
| | - Xiaoli Ma
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China
| | - Jin Yan
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China
| | - Kailin Xu
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China
| | - Qing Wang
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China
| | - Hui Li
- College of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, People's Republic of China.
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5
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Zhan T, Yang Q, Zhang Y, Wang X, Xu J, Hou W. Structural characterization and electrocatalytic application of hemoglobin immobilized in layered double hydroxides modified with hydroxyl functionalized ionic liquid. J Colloid Interface Sci 2014; 433:49-57. [DOI: 10.1016/j.jcis.2014.07.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Tianrong Zhan
- State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
| | - Qi Yang
- State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Yumei Zhang
- State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Xinjun Wang
- State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Jie Xu
- State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Wanguo Hou
- Key Laboratory of Colloid & Interface Chemistry (Ministry of Education), Shandong University, Jinan 250100, China.
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da Silva JAB, Moreira FGB, dos Santos VML, Longo RL. Topological analyses and small-world patterns of hydrogen bond networks in water + t-butanol, water + n-butanol and water + ammonia mixtures. Phys Chem Chem Phys 2014; 16:19479-91. [DOI: 10.1039/c4cp02130d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
H-bond networks in aqueous mixtures obtained by Monte Carlo simulations and analyzed by statistical mechanics based tools revealed small-word patterns.
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Affiliation(s)
- Juliana Angeiras Batista da Silva
- Núcleo de Formação Docente
- Centro Acadêmico do Agreste
- Universidade Federal de Pernambuco
- Caruaru, Brazil
- Departamento de Química Fundamental
| | | | | | - Ricardo Luiz Longo
- Departamento de Química Fundamental
- Universidade Federal de Pernambuco
- Recife, Brazil
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7
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Hicks T, Verbeek CJR, Lay MC, Bier JM. Effect of oxidative treatment on the secondary structure of decoloured bloodmeal. RSC Adv 2014. [DOI: 10.1039/c4ra03890h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Synchrotron-based Fourier-transform infrared (FTIR) spectroscopy was used to assess the effect of peracetic acid decolouring on the spatial distribution of secondary structures within particles of bloodmeal.
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Affiliation(s)
- Talia Hicks
- School of Engineering
- Faculty of Science and Engineering
- University of Waikato
- Hamilton 3240, New Zealand
| | - Casparus J. R. Verbeek
- School of Engineering
- Faculty of Science and Engineering
- University of Waikato
- Hamilton 3240, New Zealand
| | - Mark C. Lay
- School of Engineering
- Faculty of Science and Engineering
- University of Waikato
- Hamilton 3240, New Zealand
| | - James M. Bier
- School of Engineering
- Faculty of Science and Engineering
- University of Waikato
- Hamilton 3240, New Zealand
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8
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Liu J, Dong Y, Zheng J, He Y, Sheng Q. Investigation on the conformation change of hemoglobin immobilized on MPA-modified electrode by electrochemical method. ANAL SCI 2013; 29:1075-81. [PMID: 24212734 DOI: 10.2116/analsci.29.1075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The conformation change of bovine hemoglobin (Hb) during the unfolding process induced by urea and acid was investigated by an electrochemical method. Hb unfolding induced by urea of different concentrations was realized by bonding Hb onto a 3-mercaptopropionic acid (MPA) modified gold electrode. The difference in unfolding percentage showed that the Hb unfolding induced by urea was a two-step, three-state transition process, while the unfolding induced by acid was a two-state transition process. The results obtained by the electrochemical method coincided closely with those obtained by UV-vis spectroscopy and fluorescence spectroscopy. Some thermodynamic parameters during the conformational change were also calculated to study the intermediate state during the Hb unfolding process. The present work may lead to an easy and effective way to study metalloproteins unfolding, and holds great promise for the design of novel sensitive biosensors.
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Affiliation(s)
- Jianbo Liu
- Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University
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9
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Hicks TM, Verbeek CJR, Lay MC, Manley-Harris M. The Role of Peracetic Acid in Bloodmeal Decoloring. J AM OIL CHEM SOC 2013. [DOI: 10.1007/s11746-013-2304-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Pabbathi A, Patra S, Samanta A. Structural transformation of bovine serum albumin induced by dimethyl sulfoxide and probed by fluorescence correlation spectroscopy and additional methods. Chemphyschem 2013; 14:2441-9. [PMID: 23780704 DOI: 10.1002/cphc.201300313] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/01/2013] [Indexed: 11/10/2022]
Abstract
Determining the structure of a protein and its transformation under different conditions is key to understanding its activity. The structural stability and activity of proteins in aqueous-organic solvent mixtures, which is an intriguing topic of research in biochemistry, is dependent on the nature of the protein and the properties of the medium. Herein, the effect of a commonly used cosolvent, dimethyl sulfoxide (DMSO), on the structure and conformational dynamics of bovine serum albumin (BSA) protein is studied by fluorescence correlation spectroscopy (FCS) measurements on fluorescein isothiocyanate (FITC)-labeled BSA. The FCS study reveals a change of the hydrodynamic radius of BSA from 3.7 nm in the native state to 7.0 nm in the presence of 40% DMSO, which suggests complete unfolding of the protein under these conditions. Fluorescence self-quenching of FITC has been exploited to understand the conformational dynamics of BSA. The time constant of the conformational dynamics of BSA is found to change from 35 μs in its native state to 50 μs as the protein unfolds with increasing DMSO concentration. The FCS results are corroborated by the near-UV circular dichroism spectra of the protein, which suggest a loss of its tertiary structure with increasing concentration of DMSO. The intrinsic fluorescence of BSA and the fluorescence response of 1-anilinonaphthalene-8-sulfonic acid, used as a probe molecule, provide information that is consistent with the FCS measurements, except that aggregation of BSA is observed in the presence of 40% DMSO in the ensemble measurements.
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Affiliation(s)
- Ashok Pabbathi
- School of Chemistry, University of Hyderabad, Gachi Bowli, Hyderabad, India
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11
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Batista ANL, Batista Jr JM, Bolzani VS, Furlan M, Blanch EW. Selective DMSO-induced conformational changes in proteins from Raman optical activity. Phys Chem Chem Phys 2013; 15:20147-52. [DOI: 10.1039/c3cp53525h] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Sandhya B, Hegde AH, Seetharamappa J. Elucidation of binding mechanism and identification of binding site for an anti HIV drug, stavudine on human blood proteins. Mol Biol Rep 2012; 40:3817-27. [DOI: 10.1007/s11033-012-2460-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 12/18/2012] [Indexed: 11/24/2022]
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13
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Chen K, Merkel TJ, Pandya A, Napier ME, Luft JC, Daniel W, Sheiko S, DeSimone JM. Low modulus biomimetic microgel particles with high loading of hemoglobin. Biomacromolecules 2012; 13:2748-59. [PMID: 22852860 DOI: 10.1021/bm3007242] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We synthesized extremely deformable red blood cell-like microgel particles and loaded them with bovine hemoglobin (Hb) to potentiate oxygen transport. With similar shape and size as red blood cells (RBCs), the particles were fabricated using the PRINT (particle replication in nonwetting templates) technique. Low cross-linking of the hydrogel resulted in very low mesh density for these particles, allowing passive diffusion of hemoglobin throughout the particles. Hb was secured in the particles through covalent conjugation of the lysine groups of Hb to carboxyl groups in the particles via EDC/NHS coupling. Confocal microscopy of particles bound to fluorescent dye-labeled Hb confirmed the uniform distribution of Hb throughout the particle interior, as opposed to the surface conjugation only. High loading ratios, up to 5 times the amount of Hb to polymer by weight, were obtained without a significant effect on particle stability and shape, though particle diameter decreased slightly with Hb conjugation. Analysis of the protein by circular dichroism (CD) spectroscopy showed that the secondary structure of Hb was unperturbed by conjugation to the particles. Methemoglobin in the particles could be maintained at a low level and the loaded Hb could still bind oxygen, as studied by UV-vis spectroscopy. Hb-loaded particles with moderate loading ratios demonstrated excellent deformability in microfluidic devices, easily deforming to pass through restricted pores half as wide as the diameter of the particles. The suspension of concentrated particles with a Hb concentration of 5.2 g/dL showed comparable viscosity to that of mouse blood, and the particles remained intact even after being sheared at a constant high rate (1000 1/s) for 10 min. Armed with the ability to control size, shape, deformability, and loading of Hb into RBC mimics, we will discuss the implications for artificial blood.
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Affiliation(s)
- Kai Chen
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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14
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Zhang H, Cao J, Fei Z, Wang Y. Investigation on the interaction behavior between bisphenol A and pepsin by spectral and docking studies. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.04.072] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Study on specific interaction of new ferrocene-substituted carborane conjugates with hemoglobin protein. Sci China Chem 2012. [DOI: 10.1007/s11426-011-4490-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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16
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Relationship between digestibility and secondary structure of raw and thermally treated legume proteins: a Fourier transform infrared (FT-IR) spectroscopic study. Amino Acids 2011; 43:911-21. [PMID: 22102054 DOI: 10.1007/s00726-011-1151-4] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 11/05/2011] [Indexed: 10/15/2022]
Abstract
The secondary structure of proteins in legumes, cereals, milk products and chicken meat was studied by diffuse reflectance infrared spectroscopy in the region of the amide I band. Major secondary structure components ( β-sheets, random coil, α-helix, turns), together with the low- and high-frequency side contributions, were resolved and related to the in vitro digestibility behaviour of the different foods. A strong inverse correlation between the relative spectral weights of the β-sheet structures and in vitro protein digestibility values was measured. Structural modifications in legume proteins induced by autoclaving were monitored by the changes in the amide I spectra. The results indicate that the β-sheet structures of raw legume proteins and the intermolecular β-sheet aggregates, arising upon heating, are primary factors in adversely affecting the digestibility.
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17
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Cheng H, Liu H, Bao W, Zou G. Studies on the interaction between docetaxel and human hemoglobin by spectroscopic analysis and molecular docking. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 105:126-32. [PMID: 21924621 DOI: 10.1016/j.jphotobiol.2011.07.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 06/15/2011] [Accepted: 07/11/2011] [Indexed: 11/30/2022]
Abstract
The binding reaction between docetaxel (DTX) and human hemoglobin (HHb) was investigated systematically with various spectroscopic methods including fluorescence quenching technique, ultraviolet (UV)-vis absorption, synchronous fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Analysis of fluorescence data showed that the quenching mechanism was the dynamic quenching and each protein had only one binding site for the drug. Two thermodynamic parameters, the enthalpy change and the entropy change were calculated to be 9.18 kJ mol(-1) and 116J mol(-1) K(-1), respectively, which suggested that hydrophobic interaction played a major role in the binding reaction. The results from different spectroscopic methods also showed that DTX could induce conformational changes of HHb. The molecular docking simulation demonstrated that DTX was located in the central cavity of HHb.
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Affiliation(s)
- Hongxia Cheng
- State Key Laboratory of Virology, College of Life Sciences, Center of Nanoscience and Nanotechnology, Wuhan University, Wuhan 430072, China
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18
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Fang R, Jing H, Chai Z, Zhao G, Stoll S, Ren F, Liu F, Leng X. Study of the physicochemical properties of the BSA: flavonoid nanoparticle. Eur Food Res Technol 2011. [DOI: 10.1007/s00217-011-1522-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Direct probing of the folding/unfolding event of bovine hemoglobin at montmorillonite clay modified electrode by adsorptive-transfer voltammetry. Talanta 2011; 84:148-54. [DOI: 10.1016/j.talanta.2010.12.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Revised: 12/16/2010] [Accepted: 12/21/2010] [Indexed: 11/22/2022]
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20
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Fan J, Zhou J, Sun T, Lü S, Tang J, Lü J. Multi-spectroscopic Study on the Interaction between CdTe Quantum Dots and Bovine Serum Albumin. CHINESE J CHEM 2011. [DOI: 10.1002/cjoc.201190003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Wu C, Xu B, Zhao J, Jiang Q, Wei F, Jiang H, Wang X, Yan H. Ferrocene-Substituted Dithio-o-Carborane Isomers: Influence on the Native Conformation of Myoglobin Protein. Chemistry 2010; 16:8914-22. [DOI: 10.1002/chem.201000605] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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Mai Z, Zhao X, Dai Z, Zou X. Contributions of Components in Guanidine Hydrochloride to Hemoglobin Unfolding Investigated by Protein Film Electrochemistry. J Phys Chem B 2010; 114:7090-7. [DOI: 10.1021/jp101082d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Zhibin Mai
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China, and College of Light Industry and Food Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China
| | - Xiaojuan Zhao
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China, and College of Light Industry and Food Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China
| | - Zong Dai
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China, and College of Light Industry and Food Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China
| | - Xiaoyong Zou
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China, and College of Light Industry and Food Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China
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Mandal P, Bardhan M, Ganguly T. A detailed spectroscopic study on the interaction of Rhodamine 6G with human hemoglobin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 99:78-86. [DOI: 10.1016/j.jphotobiol.2010.02.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 01/29/2010] [Accepted: 02/23/2010] [Indexed: 10/19/2022]
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24
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Mandal P, Ganguly T. Fluorescence Spectroscopic Characterization of the Interaction of Human Adult Hemoglobin and Two Isatins, 1-Methylisatin and 1-Phenylisatin: A Comparative Study. J Phys Chem B 2009; 113:14904-13. [DOI: 10.1021/jp9062115] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Paulami Mandal
- Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Tapan Ganguly
- Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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25
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An Z, Lu S, He J, Wang Y. Colloidal assembly of proteins with delaminated lamellas of layered metal hydroxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10704-10710. [PMID: 19689160 DOI: 10.1021/la901205c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The colloidal LDH nanosheets have been assembled in aqueous medium with three proteins having different structures and surface charge distributions. In addition to the interfacial adsorption features, the secondary and/or higher level structures of surface-bound proteins are investigated by ATR-FTIR and fluorescence spectroscopic techniques. The structure and conformation of porcine pancreatic lipase (PPL), for which the negative charges are concentrated on the side surface opposite to active sites, are well retained, but the orientations of PPL molecules on two-dimensional LDH nanosheets could be lying flat or standing up depending on the PPL/LDH ratio. The bioactivity of PPL lying flat is enhanced in both the hydrolysis and kinetic resolution in comparison with its soluble counterpart. In the case of hemoglobin (Hb), a tetrameric hemeprotein with relatively uniform distribution of surface negative charges, the interfacial assembly might result in the unfolding of its tertiary or quaternary structure, but its secondary structure and redox-active heme groups are not denatured. Although the secondary structure of bovine serum albumin (BSA), for which the negative charges are distributed along the surfaces of linearly arranged domains I and II, is unfolded, the loss of the ordered structure is less than previously found owing to the less curvature of the two-dimensional LDH nanosheet surface. This is the first report related to the investigations of protein structures, conformations, and orientations in the biohybrids consisting of LDH nanosheets.
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Affiliation(s)
- Zhe An
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
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26
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Guerrero-Mendiola C, Oria-Hernández J, Ramírez-Silva L. Kinetics of the thermal inactivation and aggregate formation of rabbit muscle pyruvate kinase in the presence of trehalose. Arch Biochem Biophys 2009; 490:129-36. [PMID: 19703407 DOI: 10.1016/j.abb.2009.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 08/19/2009] [Accepted: 08/19/2009] [Indexed: 11/29/2022]
Abstract
In a previous study we found that 30-40% dimethylsulfoxide induces the active conformation of rabbit muscle pyruvate kinase. Because dimethylsulfoxide is known to perturb structure and function of many proteins, we have explored the effect of trehalose on the kinetics of thermal inactivation and stability of pyruvate kinase; this is because trehalose, in contrast to dimethyl sulfoxide, is totally excluded from the hydration shell of proteins. The results show that 600 mM trehalose inhibits the activity of pyruvate kinase by about 20% at 25 degrees C, however, trehalose protects pyruvate kinase from thermal inactivation at 60 degrees C, increases the Tm(app) of unfolding by 7.2 degrees C, induces a more compact state, and stabilizes its tetrameric structure. The inactivation process is irreversible due to the formation of protein aggregates. Trehalose diminishes the rate of formation of intermediates with propensity to aggregate, but does not affect the extent of aggregation. Remarkably, trehalose affects the aggregation process by inducing aggregates with amyloid-like characteristics.
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Affiliation(s)
- Carlos Guerrero-Mendiola
- Departamento de Bioquímica, Facultad de Medicina, Apartado Postal 70-159, Universidad Nacional Autónoma de México, 04510 México, DF, Mexico
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27
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Selling GW, Woods KK, Biswas A, Willett JL. Reactive extrusion of zein with glyoxal. J Appl Polym Sci 2009. [DOI: 10.1002/app.30074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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28
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Mousavy SJ, Riazi GH, Kamarei M, Aliakbarian H, Sattarahmady N, Sharifizadeh A, Safarian S, Ahmad F, Moosavi–Movahedi AA. Effects of mobile phone radiofrequency on the structure and function of the normal human hemoglobin. Int J Biol Macromol 2009; 44:278-85. [DOI: 10.1016/j.ijbiomac.2009.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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29
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Khan SN, Islam B, Yennamalli R, Zia Q, Subbarao N, Khan AU. Characterization of doxorubicin binding site and drug induced alteration in the functionally important structural state of oxyhemoglobin. J Pharm Biomed Anal 2008; 48:1096-104. [DOI: 10.1016/j.jpba.2008.08.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 08/12/2008] [Accepted: 08/21/2008] [Indexed: 10/21/2022]
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30
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Zhang S, Gerhard GS. Heme activates artemisinin more efficiently than hemin, inorganic iron, or hemoglobin. Bioorg Med Chem 2008; 16:7853-61. [PMID: 18676152 DOI: 10.1016/j.bmc.2008.02.034] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 02/08/2008] [Accepted: 02/11/2008] [Indexed: 11/15/2022]
Abstract
Artemisinin derivatives appear to mediate their anti-malarial through an initial redox-mediated reaction. Heme, inorganic iron, and hemoglobin have all been implicated as the key molecules that activate artemisinins. The reactions of artemisinin with different redox forms of heme, ferrous iron, and deoxygenated and oxygenated hemoglobin were analyzed under similar in vitro conditions. Heme reacted with artemisinin much more efficiently than the other iron-containing molecules, supporting the role of redox active heme as the primary activator of artemisinin.
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Affiliation(s)
- Shiming Zhang
- Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA.
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31
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Shen XC, Liou XY, Ye LP, Liang H, Wang ZY. Spectroscopic studies on the interaction between human hemoglobin and CdS quantum dots. J Colloid Interface Sci 2007; 311:400-6. [PMID: 17433354 DOI: 10.1016/j.jcis.2007.03.006] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2006] [Revised: 02/28/2007] [Accepted: 03/01/2007] [Indexed: 10/23/2022]
Abstract
The interaction between human adult hemoglobin (Hb) and bare CdS quantum dots (QDs) was investigated by fluorescence, synchronous fluorescence, circular dichroism (CD), and Raman spectroscopic techniques under physiological pH 7.43. The intrinsic fluorescence of Hb is statically quenched by CdS QDs. The quenching obeys the Stern-Volmer equation, with an order of magnitude of binding constant (K) of 10(7). The electrostatic adsorption of Hb on the cationic CdS QDs surface is energetically favorable (DeltaS(0)=70.22 Jmol(-1)K(-1), DeltaH(0)=-23.11 kJmol(-1)). The red shift of synchronous fluorescence spectra revealed that the microenvironments of tryptophan and tyrosine residues at the alpha(1)beta(2) interface of Hb are disturbed by CdS QDs, which are induced from hydrophobic cavities to a more exposed or hydrophilic surrounding. The secondary structure of the adsorbed Hb has a loose or extended conformation for which the content of alpha-helix has decreased from 72.5 to 60.8%. Moreover, Raman spectra results indicated that the sulfur atoms of the cysteine residues form direct chemical bonds on the surface of the CdS QDs. The binding does not significantly affect the spin state of the heme iron, and deoxidation is not expected to take place on the coated oxyhemoglobin. The change of orientation of heme vinyl groups was also detected.
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Affiliation(s)
- Xing-Can Shen
- College of Chemistry and Chemical Engineering, Key Laboratory of Medicinal Chemical Resources and Molecular Engineering, Guangxi Normal University, 15 YuCai Road, Guilin 541004, People's Republic of China.
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32
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Abe S, Takahashi H. A comparative study of the effects of dimethylsulfoxide and glycerol on the bicontinuous cubic structure of hydrated monoolein and its phase behavior. Chem Phys Lipids 2007; 147:59-68. [PMID: 17451662 DOI: 10.1016/j.chemphyslip.2007.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Revised: 03/11/2007] [Accepted: 03/15/2007] [Indexed: 10/23/2022]
Abstract
Both dimethylsulfoxide (DMSO) and glycerol act cryoprotectants for biological systems and materials. Knowledge of molecular interactions of DMSO and glycerol with biological lipids is important for understanding of their cryoprotecitive mechanisms. In this study, the phase behavior and structures of hydrated monoolein were investigated in the presence of DMSO or glycerol, using differential scanning calorimetry (DSC) and simultaneous X-ray diffraction/DSC measurements. Based on the results obtained by this study, partial phase diagrams were constructed as a function of DMSO or glycerol concentrations and temperature. DMSO and glycerol hardly affect the enthalpy value for melting temperature of lamellar crystal phase of monoolein and the structure. On the other hand, DMSO and glycerol greatly affect the phase transformations associated with bicontinuous cubic phases of monoolein and the cubic phase structures. DMSO expands Im3m/Pn3m cubic phase co-existence region in the phase diagram and increases the lattice constant of the Pn3m monoolein cubic phase. Glycerol shows opposite effects. The present study suggests that different mechanisms act in the cryopreservation by DMSO and glycerol.
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Affiliation(s)
- Satoru Abe
- Biophysics Laboratory, Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Aramaki 4-2, Maebashi 371-8510, Japan
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33
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Selling GW, Biswas A, Patel A, Walls DJ, Dunlap C, Wei Y. Impact of Solvent on Electrospinning of Zein and Analysis of Resulting Fibers. MACROMOL CHEM PHYS 2007. [DOI: 10.1002/macp.200700056] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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34
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Urabe Y, Shiomi T, Itoh T, Kawai A, Tsunoda T, Mizukami F, Sakaguchi K. Encapsulation of Hemoglobin in Mesoporous Silica (FSM)—Enhanced Thermal Stability and Resistance to Denaturants. Chembiochem 2007; 8:668-74. [PMID: 17330900 DOI: 10.1002/cbic.200600486] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hemoblogin (Hb), which is a typical oligomeric protein, was introduced into the pores of mesoporous silica (FSM: folded-sheet mesoporous material) that had a diameter of 7.5 nm. Soret CD spectra of Hb-FSM-7.5 conjugates showed a peak that was identical to that of free Hb. This suggests that Hb retained its highly ordered structure in the mesoporous silica. In addition, the UV-visible absorption spectrum showed that Hb had an increased resistance to heat denaturation in the silica. Even after heat treatment at 85 degrees C, Hb-FSM-7.5 retained its ligand-binding activity. The stability of Hb-FSM-7.5 was examined further by measuring its peroxidase-like activity. Encapsulation of Hb resulted in the retention of activity in the presence of high NaCl or Gdn-HCl levels. This suggests that encapsulation prevented dissociation and denaturing. Thus, it seems that the mesopores created a favorable environment for the oligomeric protein to perform its function, even under harsh conditions.
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Affiliation(s)
- Yoko Urabe
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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Itoh T, Ishii R, Ebina T, Hanaoka T, Ikeda T, Urabe Y, Fukushima Y, Mizukami F. Effective immobilization of subunit protein in mesoporous silica modified with ethanol. Biotechnol Bioeng 2007; 97:200-5. [PMID: 17054125 DOI: 10.1002/bit.21231] [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: 11/06/2022]
Abstract
Ethoxylated FSM-type mesoporous silica (folded-sheet mesoporous material) with a pore diameter of 6.2 nm (FSM6.2) remarkably enhances rigidly of the structure in aqueous solutions. The esterified material could be used successfully as an adsorbent to accommodate subunit protein, methemoglobin (Fe(3+)). Furthermore, methemoglobin (Fe(3+)) in the pores of ethoxy-FSM is maintained a peroxidase activity similar to the native, indicating methemoglobin retains its fore subunit structure in the pores of FSM6.2.
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Affiliation(s)
- Tetsuji Itoh
- National Institute of Advanced Industrial Science and Technology (AIST), Nigatake 4-2-1, Miyagino-ku, Sendai 983-8551, Japan.
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36
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Messori L, Gabbiani C, Casini A, Siragusa M, Vincieri FF, Bilia AR. The reaction of artemisinins with hemoglobin: A unified picture. Bioorg Med Chem 2006; 14:2972-7. [PMID: 16412643 DOI: 10.1016/j.bmc.2005.12.038] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 12/07/2005] [Accepted: 12/09/2005] [Indexed: 11/22/2022]
Abstract
The reactions with hemoglobin of artemisinin and of its parent compounds, sodium artesunate and dihydroartemisinin, were investigated by visible absorption spectroscopy under standard solution conditions (50 mM phosphate buffer, pH 7, 37 degrees C). Notably, these antimalarial drugs were found to react with hemoglobin (i.e., ferrous heme), but not with methemoglobin (i.e., ferric heme). The reaction selectively occurs at the heme sites and consists of the progressive, slow decay of the Soret band, as a consequence of heme alkylation and subsequent loss of pi electron delocalization. For the various tested compounds the process reaches completion within approximately 30-70 h. Additional experiments were carried out upon adopting the solution conditions described by Meunier et al. and by Kannan et al. in their recent studies. Some reactivity of artemisinin with methemoglobin was indeed detected after addition of 50% v/v acetonitrile, most likely as a consequence of extensive protein unfolding. A unified description for the reactions of artemisinins with hemoglobin is given.
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Affiliation(s)
- Luigi Messori
- Department of Chemistry, University of Florence, Florence, Italy.
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37
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Teramoto H, Miyazawa M. Molecular Orientation Behavior of Silk Sericin Film as Revealed by ATR Infrared Spectroscopy. Biomacromolecules 2005; 6:2049-57. [PMID: 16004444 DOI: 10.1021/bm0500547] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper reports the structure-dependent molecular orientation behavior of sericin, an adhesive silk protein secreted by silkworm, Bombyx mori. Although application of sericin as a biomaterial is anticipated because of its unique characteristics, sericin's physicochemical properties remain unclear, mainly because of its vulnerability to heat or alkaline treatment during separation from fibroin threads. This study employed intact sericin obtained from fibroin-deficient mutant silkworm to investigate the relationship between molecular orientation and the secondary structure of sericin. Sericin films were artificially stretched after moistening with aqueous ethanol of various concentrations. The resulting molecular orientation was analyzed using polarized infrared spectroscopy. These analyses indicated that formation of aggregated strands among extended sericin chains induced by ethanol treatment is the key to generating molecular orientation. Strong intermolecular hydrogen bonds are inferred to allow aggregated strands' stretching-force transmission, thereby causing molecular orientation.
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Affiliation(s)
- Hidetoshi Teramoto
- New Silk Materials Laboratory, Insect Biotechnology and Sericology Department, National Institute of Agrobiological Sciences, 1-4-8 Gohda, Okaya, Nagano 394-0021, Japan
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38
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Zhang W, Zhou H, Li G, Scheer H. An electrochemical study of hemoglobin in water–glycerol solutions. Biophys Chem 2004; 111:229-33. [PMID: 15501566 DOI: 10.1016/j.bpc.2004.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Revised: 06/04/2004] [Accepted: 06/07/2004] [Indexed: 11/30/2022]
Abstract
The effect the composition of a water-glycerol mixture has on the electrochemical properties of hemoglobin (Hb) is studied. With the increased glycerol concentrations, the peak-to-peak separation of hemoglobin is found to increase from approximately 40 to 200 mV, with the apparent standard potential of hemoglobin negatively shifted, which demonstrate that the electron-transfer activity of hemoglobin will decrease at relatively high glycerol concentrations and the oxidized state of hemoglobin will be more stable with the increasing glycerol concentrations. Meanwhile, the electrocatalytic activity of hemoglobin to hydrogen peroxide, as well as the binding of ligands or effectors to hemoglobin in the presence of glycerol, are also been investigated. Our studies indicate that glycerol will decrease the electrocatalytic activity of hemoglobin, while have little effect on the microenvironment around the heme site.
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Affiliation(s)
- Wenjun Zhang
- Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, PR China
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39
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Ajloo D, Moosavi-Movahedi AA. Kinetics of denaturation of human and chicken hemoglobins in the presence of co-solvents. JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 36:367-72. [PMID: 12895294 DOI: 10.5483/bmbrep.2003.36.4.367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The stability of four hemoglobins (Hb) in dimer forms (low concentration) were investigated by the kinetics of denaturation. The rate constants of denaturation were obtained by variation of 280 nm absorption versus time in 10 mM Tris-HCl, 10 mM EDTA, pH 8.0 at 45 degrees C in the absence and presence of 0.5 M ethanol, dimethyl sulfoxide (DMSO), formamide, and glycerol. The results show the trend of rate constants in different co-solvents in the following order: chicken hemolysate < human hemolysate and chicken Hb D < chicken Hb A. The buried surface area was calculated for Hb samples in the absence of co-solvents. Accordingly, the trend points out that: chicken Hb D > chicken Hb A > human Hb A. These results suggest that both chicken hemolysate and chicken Hb D are relatively more stable than human and chicken Hb A, respectively. However, the denaturation rate constants of Hb in different co-solvents have designated the following order: ethanol > DMSO > formamide > glycerol. As a matter of fact, this phenomenon is an indication of an increase in the denaturation capacity (DC) and hydrophobicity, and a decrease in the surface tension of the solution in the preceding co-solvents.
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Affiliation(s)
- Davood Ajloo
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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40
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Arshava B, Taran I, Xie H, Becker JM, Naider F. High resolution NMR analysis of the seven transmembrane domains of a heptahelical receptor in organic-aqueous medium. Biopolymers 2002; 64:161-76. [PMID: 12012351 DOI: 10.1002/bip.10157] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The NMR properties of seven peptides representing the transmembrane domains of the alpha-factor receptor from Saccharomyces cerevisiae were examined in trifluoroethanol/water (4:1) at 10 to 55 degrees C. The parameters extracted indicated all peptides were helical in this membrane mimetic solvent. Using chemical shift indices as the criterion, helicity varied from 64 to 83%. The helical residues in the peptides corresponded to the region predicted to cross the hydrocarbon interior of the bilayer. A study of a truncated 25-residue peptide corresponding to domain 2 gave evidence that the helix extended all the way to the N-terminus of this peptide, indicating that sequence and not chain end effects are very important in helix termination for our model peptides. Both nuclear Overhauser effect spectroscopy (NOESY) connectivities and chemical shift indices revealed significant perturbations around prolyl residues in the helices formed by transmembrane domains 6 and 7. Molecular models of the transmembrane domains indicate that helices for domains 6 and 7 are severely kinked at these prolyl residues. The helix perturbation around proline 258 in transmembrane domain 6 correlates with mutations that cause phenotypic changes in this receptor.
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Affiliation(s)
- Boris Arshava
- Department of Chemistry, The College of Staten Island, Graduate Center of the City University of New York, Staten Island, NY 10314, USA
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41
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Fan C, Lu J, Zhang W, Suzuki I, Li G. Enhanced Electron-Transfer Reactivity of Cytochrome b5by Dimethylsulfoxide and N,N'-Dimethylformamide. ANAL SCI 2002; 18:1031-3. [PMID: 12243399 DOI: 10.2116/analsci.18.1031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Chunhai Fan
- Department of Biochemistry, Nanjing University, PR China
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Ramírez-Silva L, Ferreira ST, Nowak T, Tuena de Gómez-Puyou M, Gómez-Puyou A. Dimethylsulfoxide promotes K+-independent activity of pyruvate kinase and the acquisition of the active catalytic conformation. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3267-74. [PMID: 11389729 DOI: 10.1046/j.1432-1327.2001.02222.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pyruvate kinase requires K+ for maximal activity; the enzyme exhibits 0.02% of maximal activity in its absence [Kayne, F. J. (1971) Arch. Biochem. Biophys. 143, 232-239]. However, pyruvate kinase entrapped in reverse micelles exhibits an important K+-independent activity [Ramírez-Silva, L., Tuena de Gómez-Puyou, M., & Gómez-Puyou, A. (1993) Biochemistry 32, 5332-5338]. It is possible that the amount of water, as well as interactions of the protein with the micelles, can account for this behavior. We therefore explored the solvent effects on the catalytic properties of muscle pyruvate kinase. The enzyme exhibited an activity of 19.4 micromol x min(-1) x mg(-1) in 40% dimethylsulfoxide, compared with 280 and 0.023 micromol x min(1) x mg(-1) observed with and without K+ in water, respectively. pH activity profiles and kinetic constants for the substrates of pyruvate kinase in dimethylsulfoxide without K+ were similar to those in 100% water with K+, and differed from those in water without K+. The spectral center of mass of the emission spectrum of pyruvate kinase in 100% water exhibited a blue shift of 3.5 nm in the presence of Mg(2+), phosphenolpyruvate, and K+, ligands that induce the active conformation of the enzyme. The spectral center of mass of the apoenzyme in 30-40% dimethylsulfoxide coincided with that of the enzyme-Mg(2+)-phosphenolpyruvate-K+ complex in 100% water. The water relaxation rate enhancement factor and binding of phosphenolpyruvate to the pyruvate kinase-Mn(2+)-(CH3)4N+ complex in 30-40% dimethylsulfoxide were similar to those of the pyruvate kinase-Mn(2+)-K+ complex in water. The aforementioned results indicate that when muscle pyruvate kinase is without K+, 30-40% dimethylsulfoxide induces its active conformation.
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Affiliation(s)
- L Ramírez-Silva
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, D.F., México.
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Lasch P, Petras T, Ullrich O, Backmann J, Naumann D, Grune T. Hydrogen peroxide-induced structural alterations of RNAse A. J Biol Chem 2001; 276:9492-502. [PMID: 11115501 DOI: 10.1074/jbc.m008528200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proteins exposed to oxidative stress are degraded via proteolytic pathways. In the present study, we undertook a series of in vitro experiments to establish a correlation between the structural changes induced by mild oxidation of the model protein RNase A and the proteolytic rate found upon exposure of the modified protein toward the isolated 20 S proteasome. Fourier transform infrared spectroscopy was used as a structure-sensitive probe. We report here strong experimental evidence for oxidation-induced conformational rearrangements of the model protein RNase A and, at the same time, for covalent modifications of amino acid side chains. Oxidation-related conformational changes, induced by H(2)O(2) exposure of the protein may be monitored in the amide I region, which is sensitive to changes in protein secondary structure. A comparison of the time- and H(2)O(2) concentration-dependent changes in the amide I region demonstrates a high degree of similarity to spectral alterations typical for temperature-induced unfolding of RNase A. In addition, spectral parameters of amino acid side chain marker bands (Tyr, Asp) revealed evidence for covalent modifications. Proteasome digestion measurements on oxidized RNase A revealed a specific time and H(2)O(2) concentration dependence; at low initial concentration of the oxidant, the RNase A turnover rate increases with incubation time and concentration. Based on these experimental findings, a correlation between structural alterations detected upon RNase A oxidation and proteolytic rates of RNase A is established, and possible mechanisms of the proteasome recognition process of oxidatively damaged proteins are discussed.
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Affiliation(s)
- P Lasch
- Robert Koch Institute, P 34 Biophysical Structure Analysis, D-13353 Berlin, Nordufer 20, Germany
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