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Benson KR, Gorecki J, Nikiforov A, Tsui W, Kasi RM, Kumar CV. Cytochrome c–poly(acrylic acid) conjugates with improved peroxidase turnover number. Org Biomol Chem 2019; 17:4043-4048. [DOI: 10.1039/c9ob00541b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cytochrome c–poly(acrylic acid) conjugates with 34-fold enhanced peroxidase activity due to acidification of enzyme microenvironment and suppression of wasteful intermediates.
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Affiliation(s)
- K. R. Benson
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - J. Gorecki
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - A. Nikiforov
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - W. Tsui
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - R. M. Kasi
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
- Institute of Materials Science
| | - C. V. Kumar
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
- Institute of Materials Science
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2
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Kubie L, Amori AR, Chakraborty S, Bren KL, Krauss TD. Photoinduced charge separation in single-walled carbon nanotube/protein integrated systems. NANOSCALE HORIZONS 2017; 2:163-166. [PMID: 32260660 DOI: 10.1039/c6nh00172f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Zinc-substituted cytochrome c (Zn-cyt c) is noncovalently bound to single-walled carbon nanotubes (SWNTs), causing the Zn-cyt c fluorescence to be quenched by up to 95%, primarily due to photoinduced charge transfer. Deposition of Zn-cyt c/SWNT films onto conductive oxides allows for harvesting of photoexcited electrons with an internal quantum efficiency of over 5%.
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Affiliation(s)
- Lenore Kubie
- Department of Chemistry, University of Rochester, Rochester, NY 14627, USA.
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3
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Anthonymuthu TS, Kenny EM, Bayır H. Therapies targeting lipid peroxidation in traumatic brain injury. Brain Res 2016; 1640:57-76. [PMID: 26872597 PMCID: PMC4870119 DOI: 10.1016/j.brainres.2016.02.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 02/06/2023]
Abstract
Lipid peroxidation can be broadly defined as the process of inserting a hydroperoxy group into a lipid. Polyunsaturated fatty acids present in the phospholipids are often the targets for peroxidation. Phospholipids are indispensable for normal structure of membranes. The other important function of phospholipids stems from their role as a source of lipid mediators - oxygenated free fatty acids that are derived from lipid peroxidation. In the CNS, excessive accumulation of either oxidized phospholipids or oxygenated free fatty acids may be associated with damage occurring during acute brain injury and subsequent inflammatory responses. There is a growing body of evidence that lipid peroxidation occurs after severe traumatic brain injury in humans and correlates with the injury severity and mortality. Identification of the products and sources of lipid peroxidation and its enzymatic or non-enzymatic nature is essential for the design of mechanism-based therapies. Recent progress in mass spectrometry-based lipidomics/oxidative lipidomics offers remarkable opportunities for quantitative characterization of lipid peroxidation products, providing guidance for targeted development of specific therapeutic modalities. In this review, we critically evaluate previous attempts to use non-specific antioxidants as neuroprotectors and emphasize new approaches based on recent breakthroughs in understanding of enzymatic mechanisms of lipid peroxidation associated with specific death pathways, particularly apoptosis. We also emphasize the role of different phospholipases (calcium-dependent and -independent) in hydrolysis of peroxidized phospholipids and generation of pro- and anti-inflammatory lipid mediators. This article is part of a Special Issue entitled SI:Brain injury and recovery.
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Affiliation(s)
- Tamil Selvan Anthonymuthu
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Elizabeth Megan Kenny
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Hülya Bayır
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA; Childrens׳s Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224, USA.
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Wang Z, Ando Y, Nugraheni AD, Ren C, Nagao S, Hirota S. Self-oxidation of cytochrome c at methionine80 with molecular oxygen induced by cleavage of the Met-heme iron bond. MOLECULAR BIOSYSTEMS 2015; 10:3130-7. [PMID: 25224641 DOI: 10.1039/c4mb00285g] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Met80 of cytochrome c (cyt c) has been shown to dissociate from its heme iron when cyt c interacts with cardiolipin (CL), which triggers the release of cyt c into the cytosol initiating apoptosis. We found that the mass of human cyt c increases by 16 Da in the Met80-Lys86 region by reaction with molecular oxygen in the presence of CL-containing liposomes and dithiothreitol (DTT). To investigate the effect of Met80 dissociation on the reaction of cyt c with molecular oxygen without affecting its secondary structures, a human cyt c mutant (Δ8384 cyt c) was constructed by removing two amino acids (Val83 and Gly84) from the loop containing Met80. According to MALDI-TOF-MS and tandem mass measurements, Met80 of Δ8384 cyt c was modified site-specifically to methionine sulfoxide when purified in the presence of molecular oxygen, whereas Met80 was not modified in the absence of molecular oxygen. A red-shift of the Soret band from 406 to 412 nm and absorption increase at ∼536 and ∼568 nm were observed for Δ8384 cyt c when it reacted with DTT and molecular oxygen, followed by a further red-shift of the Soret band to 416 nm and absorption increase at ∼620 and ∼650 nm. These results indicate that Met80 of cyt c is oxidized site-specifically by formation of the oxy and subsequent compound I-like species when Met80 dissociates from the heme iron, where the Met80 modification may affect its peroxidase activity related to apoptosis.
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Affiliation(s)
- Zhonghua Wang
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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5
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Rocco M, Byron O. Computing translational diffusion and sedimentation coefficients: an evaluation of experimental data and programs. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:417-31. [DOI: 10.1007/s00249-015-1042-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/04/2015] [Accepted: 05/13/2015] [Indexed: 11/28/2022]
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6
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Chandra D, Ohji T, Kato K, Kimura T. Connectivity of PS-b-PEO templated spherical pores in titanium oxide films. Phys Chem Chem Phys 2011; 13:12529-35. [DOI: 10.1039/c1cp21060b] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Shangguan X, Zheng J, Sheng Q. Direct Electron Transfer of Horseradish Peroxidase in Gellan Gum-Hydrophilic Ionic Liquid Gel Film. ELECTROANAL 2009. [DOI: 10.1002/elan.200904550] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Renault C, Balland V, Martinez-Ferrero E, Nicole L, Sanchez C, Limoges B. Highly ordered transparent mesoporous TiO2 thin films: an attractive matrix for efficient immobilization and spectroelectrochemical characterization of cytochrome c. Chem Commun (Camb) 2009:7494-6. [DOI: 10.1039/b919976d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Topoglidis E, Lutz T, Durrant JR, Palomares E. Interfacial electron transfer on cytochrome-c sensitised conformally coated mesoporous TiO2 films. Bioelectrochemistry 2008; 74:142-8. [DOI: 10.1016/j.bioelechem.2008.06.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 05/14/2008] [Accepted: 06/11/2008] [Indexed: 11/25/2022]
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10
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ElKaoutit M, Naranjo-Rodriguez I, Domínguez M, Hernández-Artiga MP, Bellido-Milla D, Hidalgo-Hidalgo de Cisneros JL. A third-generation hydrogen peroxide biosensor based on Horseradish Peroxidase (HRP) enzyme immobilized in a Nafion–Sonogel–Carbon composite. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.04.086] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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How does reorganization energy change upon protein unfolding? Monitoring the structural perturbations in the heme cavity of cytochrome c. Biophys Chem 2008; 134:225-31. [DOI: 10.1016/j.bpc.2008.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 02/17/2008] [Accepted: 02/17/2008] [Indexed: 11/21/2022]
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12
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Varhač R, Antalík M. Correlation of acid-induced conformational transition of ferricytochrome c with cyanide binding kinetics. J Biol Inorg Chem 2008; 13:713-21. [DOI: 10.1007/s00775-008-0357-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Accepted: 02/16/2008] [Indexed: 10/22/2022]
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13
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Varhac R, Antalík M, Bánó M. Effect of temperature and guanidine hydrochloride on ferrocytochrome c at neutral pH. J Biol Inorg Chem 2003; 9:12-22. [PMID: 14586787 DOI: 10.1007/s00775-003-0492-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2003] [Accepted: 09/12/2003] [Indexed: 10/26/2022]
Abstract
Thermally denatured horse heart ferrocytochrome c (ferrocyt c) has been characterized using absorption spectroscopy, differential scanning calorimetry (DSC) and viscometry at pH 7.0. DSC experiments have yielded the transition temperature of denaturant-free ferrocyt c unfolding as 100.6+/-0.3 degrees C, indicating an extremely high stability of the protein. The presence of guanidine hydrochloride (GdnHCl) facilitated estimation of the structural features of thermally unfolded ferrocyt c. The stability of the protein, expressed by Delta G(D) at 25 degrees C, is 59+/-5 kJ mol(-1) (DSC) and 65+/-6 kJ mol(-1) (absorption spectroscopy). An absorption spectrum of ferrocyt c demonstrates that the heme occurs in the high-spin state at extreme denaturing conditions (94 degrees C, 6.6 M GdnHCl). Absorption spectroscopy, using heme as a probe, shows that thermal denaturation of ferrocyt c occurs as a transition from a native low-spin (Met80/His18) to a high-spin disordered state with involvement of non-native, low-spin (bis-His) species.
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Affiliation(s)
- Rastislav Varhac
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 043 53, Kosice, Slovakia
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Abstract
Equilibrium and kinetic folding studies of horse cytochrome c in the reduced state have been carried out under strictly anaerobic conditions at neutral pH, 10 degrees C, in the entire range of aqueous solubility of guanidinium hydrochloride (GdnHCl). Equilibrium unfolding transitions observed by Soret heme absorbance, excitation energy transfer from the lone tryptophan residue to the ferrous heme, and far-UV circular dichroism (CD) are all biphasic and superimposable, implying no accumulation of structural intermediates. The thermodynamic parameters obtained by two-state analysis of these transitions yielded DeltaG(H2O)=18.8(+/-1.45) kcal mol(-1), and C(m)=5.1(+/-0.15) M GdnHCl, indicating unusual stability of reduced cytochrome c. These results have been used in conjunction with the redox potential of native cytochrome c and the known stability of oxidized cytochrome c to estimate a value of -164 mV as the redox potential of the unfolded protein. Stopped-flow kinetics of folding and unfolding have been recorded by Soret heme absorbance, and tryptophan fluorescence as observables. The refolding kinetics are monophasic in the transition region, but become biphasic as moderate to strongly native-like conditions are approached. There also is a burst folding reaction unobservable in the stopped-flow time window. Analyses of the two observable rates and their amplitudes indicate that the faster of the two rates corresponds to apparent two-state folding (U<-->N) of 80-90 % of unfolded molecules with a time constant in the range 190-550 micros estimated by linear extrapolation and model calculations. The remaining 10-20 % of the population folds to an off-pathway intermediate, I, which is required to unfold first to the initial unfolded state, U, in order to refold correctly to the native state, N (I<-->U<-->N). The slower of the two observable rates, which has a positive slope in the linear functional dependence on the denaturant concentration indicating that an unfolding process under native-like conditions indeed exists, originates from the unfolding of I to U, which rate-limits the overall folding of these 10-20 % of molecules. Both fast and slow rates are independent of protein concentration and pH of the refolding milieu, suggesting that the off-pathway intermediate is not a protein aggregate or trapped by heme misligation. The nature or type of unfolded-state heme ligation does not interfere with refolding. Equilibrium pH titration of the unfolded state yielded coupled ionization of the two non-native histidine ligands, H26 and H33, with a pK(a) value of 5.85. A substantial fraction of the unfolded population persists as the six-coordinate form even at low pH, suggesting ligation of the two methionine residues, M65 and M80. These results have been used along with the known ligand-binding properties of unfolded cytochrome c to propose a model for heme ligation dynamics. In contrast to refolding kinetics, the unfolding kinetics of reduced cytochrome c recorded by observation of Soret absorbance and tryptophan fluorescence are all slow, simple, and single-exponential. In the presence of 6.8 M GdnHCl, the unfolding time constant is approximately 300(+/-125) ms. There is no burst unfolding reaction. Simulations of the observed folding-unfolding kinetics by numerical solutions of the rate equations corresponding to the three-state I<-->U<-->N scheme have yielded the microscopic rate constants.
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Affiliation(s)
- A K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad, 500046, India.
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15
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Ahmad Z, Ahmad F. Physico-chemical characterization of products of unfolding of cytochrome c by calcium chloride. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1207:223-30. [PMID: 8075155 DOI: 10.1016/0167-4838(94)00045-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cytochrome c (cyt c) denaturation by calcium chloride (CaCl2) and guanidine hydrochloride (GdnHCl) denaturation in presence of low fixed concentrations of CaCl2 has been carried out by UV/Vis spectrophotometry at pH 7.0 and 25 degrees C. The unfolding process was followed by measuring changes in difference molar extinction coefficient around 400 nm and delta epsilon 290. The products of denaturation were further characterized by intrinsic viscosity ([eta]) measurements. It has been observed that the reversible unfolding of cyt c by CaCl2 occurs in two distinct stages or involves three species (or states) namely N<-->X<-->D. Characterization of the native state, N intermediate state, X and the end product, D suggests that (i) During N<-->X only heme is exposed and no secondary structure unfolding occurs so that X state remains as compact as the native state. (ii) Stage X<-->D shows the melting of secondary structure. (iii) The end product corresponds to a random coil. and (iv) Thermodynamic characterization of the end product shows that heme plays an important role in the stability of the protein and removal of heme will lead to the unfolding of cyt c. Mixed denaturation shows a highly cooperative reversible transition between the native and denatured conformation. Analysis of the mixed results shows that (1) Gdn+ does not have any binding site (s) on the native cyt c, (2) there is one binding site for Ca2+ which stabilizes the protein, and (3) the binding constant, ks, is 5 M-1 for Ca2+.
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Affiliation(s)
- Z Ahmad
- Centre for Biosciences, Jamia Millia Islamia, New Delhi, India
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17
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AHN D, MAURER A. Poultry Meat Color: Kinds of Heme Pigments and Concentrations of the Ligands. Poult Sci 1990. [DOI: 10.3382/ps.0690157] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Differential interactions of apo- and holocytochrome c with acidic membrane lipids in model systems and the implications for their import into mitochondria. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84950-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
The unfolding of horse ferricytochrome c in the presence of several inorganic salts has been studied under a variety of denaturing conditions and followed by means of absorbance changes in the Soret region (390-450 nm) and visible region (450-750 nm), as well as by viscosity measurements. Change in the Soret region, usually sensitive to the heme environment, were characterized by gradual increases in absorbance at 409 nm for low concentrations of NaClO4 and LiClP4. As denaturant concentrations were increased, the low-spin state of the ferric heme is altered, as seen by a maximum shift to shorter wavelengths (402-407 nm) accompanied by a further increase in absorbance in the Soret region. Unlike the effect of several organic denaturants and the above salts, denaturation in the presence of LiCl and CaCl2 resulted in an overall decrease in the Soret region with a blue-shift to 401 and 400 nm, respectively. Visible spectra of ferricytochrome c exhibited new bands at 633 nm (9.0 M LiCl) and 636 nm (4.5 M CaCl2) indicative of a change in the spin state of the iron upon displacement of methionine 80. LiCl and LiBr produced intermediate states of protein unfolding with midpoints (D 1/2) at 4.0 and 8.6, and 2.6 and 6.4, respectively. A determination of delta GHU2O and m, the free energy of unfolding in the absence of denaturant and the dependence of free energy of denaturation on denaturant concentration, was used to analyze the relative effectiveness of these denaturants.
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Abstract
The properties of the guanidine hydrochloride induced unfolding transition of iso-2 cytochrome c (iso-2) from Saccharomyces cerevisiae have been investigated by using kinetic and equilibrium techniques and have been compared with previously published studies of horse cytochrome c, which differs from iso-2 by 46% in amino acid sequence. Measurements of absorbance in the ultraviolet and visible spectral regions as a function of guanidine hydrochloride concentration give superimposable equilibrium transition curves with a midpoint of 1.15 M at pH 7.2 and 20 degrees C. A two-state analysis of the equilibrium data gives a Gibbs free energy of unfolding of 3.1 kcal/mol at 20 degrees C in the absence of denaturant. This agrees well with the predicted difference in stability between S. cerevisiae iso-2 and horse cytochrome c estimated from the free energies of transfer of buried hydrophobic groups. Three kinetic phases associated with folding can be detected throughout most of the transition zone. Two of the phases are detected by stopped-flow mixing experiments. The third phase is over within the mixing time of the flow experiments but is detectable by temperature jumps. At 20 degrees C, pH 7.2, the slowest phase (T1) is in the 20-100-s time range, the middle phase (T2) is in the 0.1-3-s range, and the fastest phase (T3) is on the order of 1 ms. For the reactions observed in the stopped flow (T1 and T2), a simplified three-state mechanism can be used to predict quantitatively the relative amplitudes of the phases and the equilibrium unfolding curve from the observed time constant data. Previously this same mechanism has been successful in describing the folding reactions of horse cytochrome c [Hagerman, P. J. (1977) Biopolymers 16, 731]. We suggest that the qualitative features of protein folding reactions may be conserved among homologous proteins.
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Ridge JA, Baldwin RL, Labhardt AM. Nature of the fast and slow refolding reactions of iron(III) cytochrome c. Biochemistry 1981; 20:1622-30. [PMID: 6261802 DOI: 10.1021/bi00509a033] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The fast and slow refolding reactions of iron(III) cytochrome c (Fe(III) cyt c), previously studied by Ikai et al. (Ikai, A., Fish, W. W., & Tanford, C. (1973) J. Mol. Biol. 73, 165--184), have been reinvestigated. The fast reaction has the major amplitude (78%) and is 100-fold faster than the slow reaction in these conditions (pH 7.2, 25 degrees C, 1.75 M guanidine hydrochloride). We show here that native cyt c is the product formed in the fast reaction as well as in the slow reaction. Two probes have been used to test for formation of native cyt c. absorbance in the 695-nm band and rate of reduction of by L-ascorbate. Different unfolded species (UF, US) give rise to the fast and slow refolding reactions, as shown both by refolding assays at different times after unfolding ("double-jump" experiments) and by the formation of native cyt c in each of the fast and slow refolding reactions. Thus the fast refolding reaction is UF leads to N and the slow refolding reaction is Us leads to N, where N is native cyt c, and there is a US in equilibrium UF equilibrium in unfolded cyt c. The results are consistent with the UF in equilibrium US reaction being proline isomerization, but this has not yet been tested in detail. Folding intermediates have been detected in both reactions. In the UF leads to N reaction, the Soret absorbance change precedes the recovery of the native 695-nm band spectrum, showing that Soret absorbance monitors the formation of a folding intermediate. In the US leads to N reaction an ascorbate-reducible intermediate has been found at an early stage in folding and the Soret absorbance change occurs together with the change at 695 nm as N is formed in the final stage of folding.
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Rönnberg M, Osterlund K, Ellfolk N. Resonance Raman spectra of Pseudomonas cytochrome c peroxidase. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 626:23-30. [PMID: 6257304 DOI: 10.1016/0005-2795(80)90193-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Resonance Raman spectra of ferric, ferrous and ferrous-carbonyl forms of Pseudomonas cytochrome c peroxidase are presented. The porphyrin ring vibration frequencies are compared with those of other heme proteins which are in well defined spin and oxidation states. Both the native oxidized and the reduced forms of the enzyme show two sets of Raman lines, one having a low-spin and the other a high-spin character. Resolved bands can be assigned to heme c and heme c', the low-spin and the high-spin moiety of the enzyme, respectively. The low-spin heme moiety of the ferric enzyme is concluded to have an imidazole-nitrogen : heme-iron : methionine-sulphur hemochrome structure, whereas in the ferrous enzyme the methionine-sulphur ligation is exchanged with the nitrogen of histidine or lysine (N epsilon). The Raman spectra indicate that the high-spin ferric heme consists of a mixture of a five-coordinated form and a six-coordinated form with a carboxylate group as a ligand. In the reduced enzyme the high-spin heme is five-coordinated. The Raman spectrum of the carbonyl derivative of Pseudomonas cytochrome c peroxidase indicates that the compound has an electron structure similar to that of carboxyhemoglobin and carboxymyoglobin. The data confirm earlier results that the two heme moieties of the enzyme are bound to the apoprotein by covalent thioether bonds as in c-type cytochromes.
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Muhoberac B, Wharton D. EPR study of heme x NO complexes of ascorbic acid-reduced Pseudomonas cytochrome oxidase and corresponding model complexes. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43515-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Osheroff N, Borden D, Koppenol W, Margoliash E. Electrostatic interactions in cytochrome c. The role of interactions between residues 13 and 90 and residues 79 and 47 in stabilizing the heme crevice structure. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)86087-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Hon-nami K, Oshima T. Denaturation of thermophilic ferricytochrome c-552 by acid, guanidine hydrochloride, and heat. Biochemistry 1979; 18:5693-7. [PMID: 229899 DOI: 10.1021/bi00592a027] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The denaturation of Thermus thermophilus cytochrome c-552 by acid, guanidine hydrochloride, and heat was studied by measuring the changes in absorption and circular dichroism. Cytochrome c-552 was remarkably resistant to acid; the pK of the transition from the low- to the high-spin form was roughly 0.3. The effect of guanidine hydrochloride on the heme iron-methionine bond of Thermus and horse cytochromes c was also investigated; a comparison of the free-energy changes for the displacement of the bond indicated that the coordination in cytochrome c-552 is highly stable. The spectra of guanidine hydrochloride unfolded cytochrome c-552 were dependent on the pH; the titration curve showed the presence of a cooperative single transition of pK = 4.7, with a one-proton dissociation, suggesting the ionization of a histidine residue. In the presence of guanidine hydrochloride, the influence of the heat on the ligand bond in cytochrome c-552 was studied. The van't Hoff plots of the reaction were biphasic. The enthalpy changes in the higher temperature range were independent on the guanidine hydrochloride concentration, while those in the lower range were not.
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31
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McLendon G, Smith M. Equilibrium and kinetic studies of unfolding of homologous cytochromes c. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34790-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Formation of a biologically active, ordered complex from two overlapping fragments of cytochrome c. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40665-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Herskovits TT, Behrens CF, Siuta PB, Pandolfelli ER. Solvent denaturation of globular proteins: unfolding by the monoalkyl- and dialkyl-substituted formamides and ureas. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 490:192-9. [PMID: 189823 DOI: 10.1016/0005-2795(77)90119-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects of the monoalkyl and dialkyl-substituted formamide series of denaturants on the native conformation of sperm whale myoglobin, horse heart cytochrome c, and Glycera dibranciata (single chain) hemoglobin have been investigated by spectral measurements in the Soret region (409 and 422 nm) and optical rotation measurements (265nm). The effectiveness of these two classes of protein denaturants is similar to the other straight-chain compounds of the urea, amide, and alcohol classes, examined in previous investigations from our laboratory. Their denaturing effectiveness is found to increase with increasing chain length or hydrocarbon content of the substituent alkyl groups. Application of the Peller and Flory equation to the denaturation data of the formamides shows that both the polar and the nonpolar group contributions to the protein-denaturant interactions have to be taken into account in order to correctly predict the observed denaturation midpoints. Additivity of the hydrophobic, KHø, and the polar, Kp, group contributions to the binding constants, KB = nKHø + Kp, with n = 1 or 2 for the mono- of the di-alkyl substituted denaturants gave best account of the experimental data. The KHø values used were based on free energy transfer data of various alkyl groups or the Scheraga-Nemethy theory of hydrophobic bonding. The assumption of group contributions of the denaturant to KB were also applied to the denaturation data of the unsubstituted amides and some examples of the monoalkyl and symmetrically substituted dialkyl ureas, taken from the literature.
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Brautigan DL, Feinberg BA, Hoffman BM, Margoliash E, Preisach J, Blumberg WE. Multiple low spin forms of the cytochrome c ferrihemochrome. EPR spectra of various eukaryotic and prokaryotic cytochromes c. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)32756-4] [Citation(s) in RCA: 176] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Sherman MR, Tuazon FB, Diaz SD, Miller LK. Multiple forms of oviduct progesterone receptors analyzed by ion exchange filtration and gel electrophoresis. Biochemistry 1976; 15:980-9. [PMID: 175833 DOI: 10.1021/bi00650a006] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Resolution of the multiple forms of steroid receptors in small samples has been improved by two new techniques: preparative ion exchange filtration and electrophoresis in highly cross-linked polyacrylamide gels of varied concentration. These techniques were used in conjunction with protamine precipitation, gel filtration, and density gradient centrifugation to separate five forms of the progesterone receptor of chick oviduct cytosol. These complexes, numbered I to V in order of elution from agarose gel columns, have been characterized with respect to apparent molecular weight, shape, and relative net charge. Form I, which is eluted in the void volume after gel filtration of cytosol in hypotonic media, is heterodisperse with respect to sedimentation coefficient and electrophoretic mobility (Rf). Form I is converted to form III by KC1. Form II has the highest axial ratio and the highest Rf at pH 10.2. This 4.2S complex can be extracted from DEAE filters, but not from protamine-precipitated cytosol, by 0.3 to 0.5 M KC1. Form III is slightly smaller (3.9S) and less asymmetric than form II. It is relased from DEAE filters and protamine-precipitated cytosol by 0.15 M KC1 and displays increased Rf upon purification. Forms II and III correspond to the B and A components described by W. T. Schrader and B. W. O'Malley ((1972), J. Biol. Chem 247, 51). Form IV may result from the proteolytic cleavage of forms II and/or III. Form V is a globular polypeptide obtained in the presence of certain divalent cations. This complex has been named the "mero-receptor" since it is the smallest part or fragment of the receptor that contains the steroid-binding site.
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Abstract
Increasing concentrations of chloride were found to increase the resolution between two visible absorbance spectral transitions associated with acidification of ferricytochrome c. Analysis of a variety of spectral and viscosity measurements indicates that protonation of a single group having an apparent pK of 2.1 +/- 0.2 and an intrinsic pK of about 5.3 displaces the methionine ligand without significantly perturbing the native globular conformation. Analysis of methylated ferricytochrome c suggests that protonation of a carboxylate ion, most likely a heme propionate residue, is responsible for displacement of the methionine ligand. Addition of a proton to a second group having an apparent pK of 1.2 +/- 0.1 displaces the histidine ligand and unfolds the protein from a globular conformation into a random coil. It is most likely that the second protonation occurs on the imidazole ring of the histidine ligand itself. Chloride is proposed to perturb these transitions by ligation in the fifth coordination position of the heme ion. Such ligation stabilizes a globular conformation of ferricytochrome c at pH 0.0 and 25 degrees.
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Stoklosa JT, Latz HW. Electrophoretic behavior of protein dodecyl sulfate complexes in the presence of various amounts of sodium dodecyl sulfate. Anal Biochem 1975; 68:358-70. [PMID: 1200343 DOI: 10.1016/0003-2697(75)90633-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Tsong TY. An acid induced conformational transition of denatured cytochrome c in urea and guanidine hydrochloride solutions. Biochemistry 1975; 14:1542-7. [PMID: 235957 DOI: 10.1021/bi00678a031] [Citation(s) in RCA: 90] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Previous work has shown that at neutral pH ferricytochrome c (horse heart) retains certain residual structures in concentrated solutions of urea or guanidine hydrochloride (Tsong, T. Y. (1974), J. Biol. Chem. 249, 1988). Present studies reveal that cooperative unfolding of these residual structures can be achieved by acidification of the protein to pH 4 in 9 M urea but can only be partially achieved in a 6 M guanidine hydrochloride solution. The evidence that the residual structures unfold in 9 M urea upon acidification is twofold. (1) Further uncoupling of the Trp-59-heme interaction occurs; this is reflected in the intensification of the tryptophan fluorescence from 55 to 90 percent relative to that of free tryptophan in the same solvent. (2) The intrinsic viscosity of the protein solution increases from 15.0 to 21 ml/g. The acidification also induces a spin-state transformation of the heme group at pH 5 both in urea and in guanidine hydrochloride. Acidic titration of the protein in urea and guanidine hydrochloride indicates that the unfolding involves the absorption of a single proton. However, the kinetics of the spin-state transformation are triphasic. These results suggest that the displacement of the ligand His-18 by a solvent molecule and the subsequent disintegration of the residual structures are complex processes and involve at least three kinetic steps. The ineffectiveness of guanidine hydrochloride as a denaturant for ferricytochrome c is shown to be due to the presence of the high concentration of Cl minus which can stabilize certain elements of the protein structure.
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Knapp JA, Pace CN. Guanidine hydrochloride and acid denaturation of horse, cow, and Candida krusei cytochromes c. Biochemistry 1974; 13:1289-94. [PMID: 4360785 DOI: 10.1021/bi00703a036] [Citation(s) in RCA: 121] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Ikai A, Fish WW, Tanford C. Kinetics of unfolding and refolding of proteins. II. Results for cytochrome c. J Mol Biol 1973; 73:165-84. [PMID: 4347736 DOI: 10.1016/0022-2836(73)90321-5] [Citation(s) in RCA: 136] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Morgan WT, Riehm JP. Proteins of the thermophilic fungus Humicola lanuginosa. II. Some physicochemical properties of a cytochrome c. Arch Biochem Biophys 1973; 154:415-21. [PMID: 4347687 DOI: 10.1016/0003-9861(73)90074-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Wilting J, Braams R, Nauta H, van Buuren KJ. The reduction mechanism of ferricytochrome c. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 283:543-7. [PMID: 4346391 DOI: 10.1016/0005-2728(72)90274-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Burkhard RK, Stolzenberg GE. Interaction between sodium dodecyl sulfate and ferricytochrome c. Biochemistry 1972; 11:1672-7. [PMID: 4623877 DOI: 10.1021/bi00759a022] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Babul J, McGowan EB, Stellwagen E. The structure of hemopeptide 1-65 from cytochrome c. Arch Biochem Biophys 1972; 148:141-7. [PMID: 5062022 DOI: 10.1016/0003-9861(72)90124-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Babul J, Stellwagen E. The existence of heme-protein coordinate-covalent bonds in denaturing solvents. Biopolymers 1971; 10:2359-61. [PMID: 5118661 DOI: 10.1002/bip.360101125] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Wilson MT, Greenwood C. Studies on ferricytochrome c. 2. A correlation between reducibility and the possession of the 695mm absorption band of ferricytochrome c. EUROPEAN JOURNAL OF BIOCHEMISTRY 1971; 22:11-8. [PMID: 5099209 DOI: 10.1111/j.1432-1033.1971.tb01508.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Greenwood C, Wilson MT. Studies on ferricytochrome c. I. Effect of pH, ionic strength and protein denaturants on the spectra of ferricytochrome c. EUROPEAN JOURNAL OF BIOCHEMISTRY 1971; 22:5-10. [PMID: 5099216 DOI: 10.1111/j.1432-1033.1971.tb01507.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Aviram I, Schejter A. Modification of the tryptophanyl residue of horse heart cytochrome c. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 229:113-8. [PMID: 5543600 DOI: 10.1016/0005-2795(71)90324-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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