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Ohgi H, Imamura H, Yonenaga K, Morita T, Nishikawa K, Westh P, Koga Y. The effect of 2,2,2-trifluoroethanol on water studied by using third derivatives of Gibbs energy, G. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.09.101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2
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Gupta S, Yadav S, Suryanarayanan V, Singh SK, Saxena JK. Investigating the folding pathway and substrate induced conformational changes in B. malayi Guanylate kinase. Int J Biol Macromol 2016; 94:621-633. [PMID: 27751808 DOI: 10.1016/j.ijbiomac.2016.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 10/01/2016] [Accepted: 10/05/2016] [Indexed: 10/20/2022]
Abstract
Guanylate kinase is one of the key enzymes in nucleotide biosynthesis. The study highlights the structural and functional properties of Brugia malayi Guanylate kinase (BmGK) in the presence of chemical denaturants. An inactive, partially unfolded, dimeric intermediate was observed at 1-2M urea while GdnCl unfolding showed monomer molten globule like intermediate at 0.8-1.0M. The results also illustrate the protective role of substrates in maintaining the integrity of the enzyme. The thermo stability of protein was found to be significantly enhanced in the presence of the substrates. Furthermore, binding of the substrates, GMP and ATP to BmGK changed its GdnCl induced unfolding pattern. Docking and molecular dynamic simulation performed for native BmGK, BmGK bound to GMP and GMP+ATP showed change in the fluctuation in the region between 130 and 150 residues. Arg134 lost its interaction with GMP and Arg145 interaction shifted to ATP after 40ns simulation upon binding of ATP to BmGK-GMP complex. We, thus, propose the importance of specific rearrangements contributed by binding of substrates which participate in the overall stability of the protein. The work here emphasizes on detailed biophysical characterization of BmGK along with the significant role of substrates in modulating the structural and functional properties of BmGK.
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Affiliation(s)
- Smita Gupta
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India
| | - Sunita Yadav
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India
| | - Venkatesan Suryanarayanan
- Computer Aided Drug Design and Molecular Modeling Lab, Department of Bioinformatics, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Sanjeev K Singh
- Computer Aided Drug Design and Molecular Modeling Lab, Department of Bioinformatics, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Jitendra K Saxena
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India.
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Inter-domain helix h10DOMI–h1DOMII is important in the molecular interaction of bovine serum albumin with curcumin: spectroscopic and computational analysis. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:139-48. [DOI: 10.1007/s00249-015-1009-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/20/2014] [Accepted: 01/16/2015] [Indexed: 12/20/2022]
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4
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Bakthisaran R, Tangirala R, Rao CM. Small heat shock proteins: Role in cellular functions and pathology. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:291-319. [PMID: 25556000 DOI: 10.1016/j.bbapap.2014.12.019] [Citation(s) in RCA: 308] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 12/16/2014] [Accepted: 12/18/2014] [Indexed: 01/18/2023]
Abstract
Small heat shock proteins (sHsps) are conserved across species and are important in stress tolerance. Many sHsps exhibit chaperone-like activity in preventing aggregation of target proteins, keeping them in a folding-competent state and refolding them by themselves or in concert with other ATP-dependent chaperones. Mutations in human sHsps result in myopathies, neuropathies and cataract. Their expression is modulated in diseases such as Alzheimer's, Parkinson's and cancer. Their ability to bind Cu2+, and suppress generation of reactive oxygen species (ROS) may have implications in Cu2+-homeostasis and neurodegenerative diseases. Circulating αB-crystallin and Hsp27 in the plasma may exhibit immunomodulatory and anti-inflammatory functions. αB-crystallin and Hsp20 exhitbit anti-platelet aggregation: these beneficial effects indicate their use as potential therapeutic agents. sHsps have roles in differentiation, proteasomal degradation, autophagy and development. sHsps exhibit a robust anti-apoptotic property, involving several stages of mitochondrial-mediated, extrinsic apoptotic as well as pro-survival pathways. Dynamic N- and C-termini and oligomeric assemblies of αB-crystallin and Hsp27 are important factors for their functions. We propose a "dynamic partitioning hypothesis" for the promiscuous interactions and pleotropic functions exhibited by sHsps. Stress tolerance and anti-apoptotic properties of sHsps have both beneficial and deleterious consequences in human health and diseases. Conditional and targeted modulation of their expression and/or activity could be used as strategies in treating several human disorders. The review attempts to provide a critical overview of sHsps and their divergent roles in cellular processes particularly in the context of human health and disease.
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Affiliation(s)
- Raman Bakthisaran
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Ramakrishna Tangirala
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Ch Mohan Rao
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
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Wang Z, Han X, He N, Chen Z, Brooks CL. Environmental Effect on Surface Immobilized Biological Molecules. J Phys Chem B 2014; 118:12176-85. [DOI: 10.1021/jp508550d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Zunliang Wang
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Si Pai Lou 2, Nanjing 210096, China
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiaofeng Han
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Si Pai Lou 2, Nanjing 210096, China
| | - Nongyue He
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Si Pai Lou 2, Nanjing 210096, China
| | - Zhan Chen
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Charles L. Brooks
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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6
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Honey-induced protein stabilization as studied by fluorescein isothiocyanate fluorescence. ScientificWorldJournal 2013; 2013:981902. [PMID: 24222758 PMCID: PMC3809590 DOI: 10.1155/2013/981902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 08/22/2013] [Indexed: 11/27/2022] Open
Abstract
Protein stabilizing potential of honey was studied on a model protein, bovine serum albumin (BSA), using extrinsic fluorescence of fluorescein isothiocyanate (FITC) as the probe. BSA was labelled with FITC using chemical coupling, and urea and thermal denaturation studies were performed on FITC-labelled BSA (FITC-BSA) both in the absence and presence of 10% and 20% (w/v) honey using FITC fluorescence at 522 nm upon excitation at 495 nm. There was an increase in the FITC fluorescence intensity upon increasing urea concentration or temperature, suggesting protein denaturation. The results from urea and thermal denaturation studies showed increased stability of protein in the presence of honey as reflected from the shift in the transition curve along with the start point and the midpoint of the transition towards higher urea concentration/temperature. Furthermore, the increase in ΔGDH2O and ΔGD25°C in presence of honey also suggested protein stabilization.
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Xia Y, Ji S, Park JS, Park I, Khoi PN, Lee J, Jung YD. Inactivation and conformational changes in methyl parathion hydrolase in 2,2,2-trifluoroethanol solutions: Inactivation kinetics and molecular dynamics simulation. Process Biochem 2013. [DOI: 10.1016/j.procbio.2013.02.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Yang B, Song Z, Zheng X, Zhao Y. Stability of proteins with multi-state unfolding behavior. Sci China Chem 2012. [DOI: 10.1007/s11426-012-4642-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Hackett MJ, Joolakanti S, Hartranft ME, Guley PC, Cho MJ. A dicarboxylic fatty acid derivative of paclitaxel for albumin-assisted drug delivery. J Pharm Sci 2012; 101:3292-304. [PMID: 22674061 DOI: 10.1002/jps.23213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/21/2012] [Accepted: 05/04/2012] [Indexed: 11/11/2022]
Abstract
Paclitaxel (PTX) is a potent chemotherapy for many cancers but it suffers from very poor solubility. Consequently, the TAXOL formulation uses copious amounts of the surfactant Cremophor EL to solubilize the drug for injection, resulting in severe hypersensitivity and neutropenia. In contrast to Cremophor EL, presented is a way to solubilize PTX by conjugation of a dicarboxylic fatty acid for specific binding to the ubiquitous protein, serum albumin. The conjugation chemistry was simplified to a single step using the activated anhydride form of 3-pentadecylglutaric (PDG) acid, which is reactive to a variety of nucleophiles. The PDG derivative is less cytotoxic than the parent compound and was found to slowly hydrolyze to PTX (≈ 5% over 72 h) in serum, tumor cytosol, and tumor tissue homogenate. When injected intravenously to tumor-bearing mice, [(3) H]-PTX in the TAXOL formulation was cleared rapidly with a half-life of 7 h. In the case of the PDG derivative of PTX, the drug is quickly distributed and approximately 20% of the injected dose remained in the vasculature experiencing a 23 h half-life. These improvements from modifying PTX with the PDG fatty acid present the opportunity for PDG to become a generic modification for the improvement of many therapeutics.
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Affiliation(s)
- Michael J Hackett
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7571, USA
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Matsuo K, Sakurada Y, Tate SI, Namatame H, Taniguchi M, Gekko K. Secondary-structure analysis of alcohol-denatured proteins by vacuum-ultraviolet circular dichroism spectroscopy. Proteins 2011; 80:281-93. [DOI: 10.1002/prot.23206] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/07/2011] [Accepted: 09/19/2011] [Indexed: 11/07/2022]
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11
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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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12
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Sen P, Ahmad B, Rabbani G, Khan RH. 2,2,2-Trifluroethanol induces simultaneous increase in α-helicity and aggregation in alkaline unfolded state of bovine serum albumin. Int J Biol Macromol 2010; 46:250-4. [DOI: 10.1016/j.ijbiomac.2009.12.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/24/2009] [Accepted: 12/24/2009] [Indexed: 11/30/2022]
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13
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Hydroimidazolone modification of human alphaA-crystallin: Effect on the chaperone function and protein refolding ability. Biochim Biophys Acta Mol Basis Dis 2010; 1802:432-41. [PMID: 20085807 DOI: 10.1016/j.bbadis.2010.01.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/21/2009] [Accepted: 01/13/2010] [Indexed: 11/20/2022]
Abstract
AlphaA-crystallin is a molecular chaperone; it prevents aggregation of denaturing proteins. We have previously demonstrated that upon modification by a metabolic alpha-dicarbonyl compound, methylglyoxal (MGO), alphaA-crystallin becomes a better chaperone. AlphaA-crystallin also assists in refolding of denatured proteins. Here, we have investigated the effect of mild modification of alphaA-crystallin by MGO (with 20-500 microM) on the chaperone function and its ability to refold denatured proteins. Under the conditions used, mildly modified protein contained mostly hydroimidazolone modifications. The modified protein exhibited an increase in chaperone function against thermal aggregation of beta(L)- and gamma-crystallins, citrate synthase (CS), malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) and chemical aggregation of insulin. The ability of the protein to assist in refolding of chemically denatured beta(L)- and gamma-crystallins, MDH and LDH, and to prevent thermal inactivation of CS were unchanged after mild modification by MGO. Prior binding of catalytically inactive, thermally denatured MDH or the hydrophobic probe, 2-p-toluidonaphthalene-6-sulfonate (TNS) abolished the ability of alphaA-crystallin to assist in the refolding of denatured MDH. However, MGO modification of chaperone-null TNS-bound alphaA-crystallin resulted in partial regain of the chaperone function. Taken together, these results demonstrate that: 1) hydroimidazolone modifications are sufficient to enhance the chaperone function of alphaA-crystallin but such modifications do not change its ability to assist in refolding of denatured proteins, 2) the sites on the alphaA-crystallin responsible for the chaperone function and refolding are the same in the native alphaA-crystallin and 3) additional hydrophobic sites exposed upon MGO modification, which are responsible for the enhanced chaperone function, do not enhance alphaA-crystallin's ability to refold denatured proteins.
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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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15
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Teixeira PCN, de Souza CAM, de Freitas MS, Foguel D, Caffarena ER, Alves LA. Predictions suggesting a participation of beta-sheet configuration in the M2 domain of the P2X(7) receptor: a novel conformation? Biophys J 2009; 96:951-63. [PMID: 19186133 DOI: 10.1016/j.bpj.2008.10.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 10/15/2008] [Indexed: 11/18/2022] Open
Abstract
Scanning experiments have shown that the putative TM2 domain of the P2X(7) receptor (P2X(7)R) lines the ionic pore. However, none has identified an alpha-helix structure, the paradigmatic secondary structure of ion channels in mammalian cells. In addition, some researchers have suggested a beta-sheet conformation in the TM2 domain of P2X(2). These data led us to investigate a new architecture within the P2X receptor family. P2X(7)R is considered an intriguing receptor because its activation induces nonselective large pore formation, in contrast to the majority of other ionic channel proteins in mammals. This receptor has two states: a low-conductance channel (approximately 10 pS) and a large pore (> 400 pS). To our knowledge, one fundamental question remains unanswered: Are the P2X(7)R channel and the pore itself the same entity or are they different structures? There are no structural data to help solve this question. Thus, we investigated the hydrophobic M2 domain with the aim of predicting the fitted position and the secondary structure of the TM2 segment from human P2X(7)R (hP2X(7)R). We provide evidence for a beta-sheet conformation, using bioinformatics algorithms and molecular-dynamics simulation in conjunction with circular dichroism in different environments and Fourier transform infrared spectroscopy. In summary, our study suggests the possibility that a segment composed of residues from part of the M2 domain and part of the putative TM2 segment of P2X(7)R is partially folded in a beta-sheet conformation, and may play an important role in channel/pore formation associated with P2X(7)R activation. It is important to note that most nonselective large pores have a transmembrane beta-sheet conformation. Thus, this study may lead to a paradigmatic change in the P2X(7)R field and/or raise new questions about this issue.
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Yazdanparast R, Khodagholi F, Souri E. Alkaline phosphatase refolding assisted by sequential use of oppositely charged detergents: a new artificial chaperone system. Int J Biol Macromol 2008; 42:195-202. [PMID: 17980423 DOI: 10.1016/j.ijbiomac.2007.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 09/22/2007] [Accepted: 09/23/2007] [Indexed: 01/14/2023]
Abstract
A novel artificial chaperone system, based on combination of oppositely charged detergents, was elaborated to refold soluble alkaline phosphatase. Upon dilution of urea-denatured alkaline phosphatase to a nondenaturing urea concentration in the presence of the capturing agent, complexes of the detergent and non-native protein molecules are formed and thereby the formation of protein aggregates is prevented. The so-called captured protein is unable to refold from the detergent-protein complex states unless a stripping agent is used to gradually remove the detergent molecules. In that respect, we used detergents with variable charges and tail lengths to initiate and complete the refolding process. The results obtained from various analyses (fluorescence, UV, circular dichroism, surface tension, turbidity measurements and activity assays) indicated that the extent of refolding assistance was different due to detergents structure and also the length of hydrophobic portion of each detergent. These observed differences were attributed to the strong electrostatic interactions among the capturing and stripping detergents used in this investigation. Collectively it is expected that protein refolding process can be achieved easier, cheaper and more efficient, using the new technique reported here.
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Affiliation(s)
- Razieh Yazdanparast
- Institute of Biochemistry and Biophysics, P.O. Box 13145-1384, University of Tehran, Tehran, Iran.
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Halim AAA, Kadir HA, Tayyab S. Bromophenol Blue Binding as a Probe to Study Urea and Guanidine Hydrochloride Denaturation of Bovine Serum Albumin. J Biochem 2008; 144:33-38. [DOI: 10.1093/jb/mvn036] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
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Khodagholi F, Eftekharzadeh B, Yazdanparast R. A New Artificial Chaperone for Protein Refolding: Sequential Use of Detergent and Alginate. Protein J 2007; 27:123-9. [DOI: 10.1007/s10930-007-9115-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Ye X, Lu Y, Liu S, Zhang G, Wu C. Ultrafast infrared heating laser pulse-induced micellization kinetics of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) in water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:10366-71. [PMID: 17705518 DOI: 10.1021/la701626k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The heating-induced micellization of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (Pluronic PE10300) triblock copolymer chains was studied by ultrasensitive differential scanning calorimetry, laser light scattering, and fluorescence spectrometry with a fluorescent probe, 8-anilino-1-naphthalenesulfonic acid ammonium salt. The critical micellization temperatures obtained from the three methods are similar. The micellization kinetics was studied in terms of changes in the fluorescence and Rayleigh scattering intensities after an ultrafast infrared heating laser pulse (approximately 10 ns)-induced temperature jump. The increases in the fluorescence and Rayleigh scattering intensities in the millisecond range can be well described by a single-exponential equation, corresponding to the incorporation of individual triblock copolymer chains (unimers) into large spherical micelles. The increase in copolymer concentration or the initial solution temperature decreases the characteristic transition time. In general, the fluorescence measurement has a better signal-to-noise ratio but leads to a transition time that is slightly shorter than that from the corresponding Rayleigh scattering measurement for a given copolymer solution.
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Affiliation(s)
- Xiaodong Ye
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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Khodagholi F, Yazdanparast R. Cooperative effects of artificial chaperone and Mg2+ ions on alkaline phosphatase refolding. Biochem Eng J 2007. [DOI: 10.1016/j.bej.2007.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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21
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Rajasekaran NS, Connell P, Christians ES, Yan LJ, Taylor RP, Orosz A, Zhang XQ, Stevenson TJ, Peshock RM, Leopold JA, Barry WH, Loscalzo J, Odelberg SJ, Benjamin IJ. Human alpha B-crystallin mutation causes oxido-reductive stress and protein aggregation cardiomyopathy in mice. Cell 2007; 130:427-39. [PMID: 17693254 PMCID: PMC2962423 DOI: 10.1016/j.cell.2007.06.044] [Citation(s) in RCA: 338] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 04/26/2007] [Accepted: 06/22/2007] [Indexed: 11/23/2022]
Abstract
The autosomal dominant mutation in the human alphaB-crystallin gene inducing a R120G amino acid exchange causes a multisystem, protein aggregation disease including cardiomyopathy. The pathogenesis of cardiomyopathy in this mutant (hR120GCryAB) is poorly understood. Here, we show that transgenic mice overexpressing cardiac-specific hR120GCryAB recapitulate the cardiomyopathy in humans and find that the mice are under reductive stress. The myopathic hearts show an increased recycling of oxidized glutathione (GSSG) to reduced glutathione (GSH), which is due to the augmented expression and enzymatic activities of glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase, and glutathione peroxidase. The intercross of hR120GCryAB cardiomyopathic animals with mice with reduced G6PD levels rescues the progeny from cardiac hypertrophy and protein aggregation. These findings demonstrate that dysregulation of G6PD activity is necessary and sufficient for maladaptive reductive stress and suggest a novel therapeutic target for abrogating R120GCryAB cardiomyopathy and heart failure in humans.
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Affiliation(s)
- Namakkal S. Rajasekaran
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Patrice Connell
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
| | - Elisabeth S. Christians
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
- Centre for Developmental Biology UMR5547, 118 route de Narbonne, 31062 Toulouse, France
| | - Liang-Jun Yan
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
| | - Ryan P. Taylor
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Andras Orosz
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Xia Q. Zhang
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Tamara J. Stevenson
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Ronald M. Peshock
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
| | - Jane A. Leopold
- Cardiovascular Medicine Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 77 Avenue Louis Pasteur Boston, MA 02115, USA
| | - William H. Barry
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Joseph Loscalzo
- Cardiovascular Medicine Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 77 Avenue Louis Pasteur Boston, MA 02115, USA
| | - Shannon J. Odelberg
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
| | - Ivor J. Benjamin
- Center for Cardiovascular Translational Biomedicine and Division of Cardiology, University of Utah, Salt Lake City, Utah 84132
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8573
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Ramachandran PV, Gong B, Teodorović AV. The influence of fluorine on the asymmetric reduction of fluoromethyl ketones. J Fluor Chem 2007. [DOI: 10.1016/j.jfluchem.2007.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Ye X, Lu Y, Shen L, Ding Y, Liu S, Zhang G, Wu C. How Many Stages in the Coil-to-Globule Transition of Linear Homopolymer Chains in a Dilute Solution? Macromolecules 2007. [DOI: 10.1021/ma070167d] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Xiaodong Ye
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Yijie Lu
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Lei Shen
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Yanwei Ding
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Shilin Liu
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Guangzhao Zhang
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
| | - Chi Wu
- The Hefei National Laboratory for Physical Sciences at Microscale and the Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong
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Akitake B, Spelbrink REJ, Anishkin A, Killian JA, de Kruijff B, Sukharev S. 2,2,2-Trifluoroethanol changes the transition kinetics and subunit interactions in the small bacterial mechanosensitive channel MscS. Biophys J 2007; 92:2771-84. [PMID: 17277184 PMCID: PMC1831691 DOI: 10.1529/biophysj.106.098715] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
2,2,2-Trifluoroethanol (TFE), a low-dielectric solvent, has recently been used as a promising tool to probe the strength of intersubunit interactions in membrane proteins. An analysis of inner membrane proteins of Escherichia coli has identified several SDS-resistant protein complexes that separate into subunits upon exposure to TFE. One of these was the homo-heptameric stretch-activated mechanosensitive channel of small conductance (MscS), a ubiquitous component of the bacterial turgor-regulation system. Here we show that a substantial fraction of MscS retains its oligomeric state in cold lithium-dodecyl-sulfate gel electrophoresis. Exposure of MscS complexes to 10-15 vol % TFE in native membranes or nonionic detergent micelles before lithium-dodecyl-sulfate electrophoresis results in a complete dissociation into monomers, suggesting that at these concentrations TFE by itself disrupts or critically compromises intersubunit interactions. Patch-clamp analysis of giant E. coli spheroplasts expressing MscS shows that exposure to TFE in lower concentrations (0.5-5.0 vol %) causes leftward shifts of the dose-response curves when applied extracellularly, and rightward shifts when added from the cytoplasmic side. In the latter case, TFE increases the rate of tension-dependent inactivation and lengthens the process of recovery to the resting state. MscS responses to pressure ramps of different speeds indicate that in the presence of TFE most channels reside in the resting state and only at tensions near the activation threshold does TFE dramatically speed up inactivation. The effect of TFE is reversible as normal channel activity returns 15-30 min after a TFE washout. We interpret the observed midpoint shifts in terms of asymmetric partitioning of TFE into the membrane and distortion of the bilayer lateral pressure profile. We also relate the increased rate of inactivation and subunit separation with the capacity of TFE to perturb buried interhelical contacts in proteins and discuss these effects in the framework of the proposed gating mechanism of MscS.
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Affiliation(s)
- Bradley Akitake
- Department of Biology, University of Maryland, College Park, Maryland
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25
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Povey JF, Smales CM, Hassard SJ, Howard MJ. Comparison of the effects of 2,2,2-trifluoroethanol on peptide and protein structure and function. J Struct Biol 2006; 157:329-38. [PMID: 16979904 DOI: 10.1016/j.jsb.2006.07.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 07/20/2006] [Accepted: 07/22/2006] [Indexed: 10/24/2022]
Abstract
The co-solvent 2,2,2-trifluoroethanol (TFE) has been often used to aid formation of secondary structure in solution peptides or alternately as a denaturant within protein folding studies. Hen egg white lysozyme (HEWL) and a synthetic model peptide defining HEWL helix-4 were used as comparative model systems to systematically investigate the effect of increasing TFE concentrations on the structure of proteins and peptides. HEWL was analyzed using NMR, far-UV CD and fluorescence spectroscopy; with correlation of these results towards changes in enzymatic activity and the helix-4 peptide was analysed using NMR. Data illustrates two conflicting modes of interaction: Low TFE concentrations stabilize tertiary structure, observed from an increase in the number of NMR NOE contacts. Higher TFE concentrations denatured HEWL with the loss of lysozyme tertiary structure. The effects of TFE upon secondary structural elements within HEWL are distinct from those observed for the helix-4 peptide. This illustrates a dissimilar interaction of TFE towards both protein and peptide at equivalent TFE concentrations. The concentration that TFE promotes stabilization over denaturation is likely to be protein dependent although the structural action can be extrapolated to other protein systems with implications for the use of TFE in structural stability studies.
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Affiliation(s)
- Jane F Povey
- Protein Science Group, Department of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
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