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Wilkinson JA, Silvera S, LeBlanc PJ. The effect of cardiolipin side chain composition on cytochrome c protein conformation and peroxidase activity. Physiol Rep 2021; 9:e14772. [PMID: 33667034 PMCID: PMC7934914 DOI: 10.14814/phy2.14772] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/21/2021] [Accepted: 02/01/2021] [Indexed: 12/26/2022] Open
Abstract
Skeletal muscle, a highly active tissue, makes up 40% of the total body weight. This tissue relies on mitochondria for ATP production, calcium homeostasis, and programed cell death. Mitochondrial phospholipid composition, namely, cardiolipin (CL), influences the functional efficiency of mitochondrial proteins, specifically cytochrome c. The interaction of CL with cytochrome c in the presence of free radicals induces structural and functional changes promoting peroxidase activity and cytochrome c release, a key event in the initiation of apoptosis. The CL acyl chain degree of saturation has been implicated in the cytochrome c to cytochrome c peroxidase transition in liposomal models. However, mitochondrial membranes are composed of differing CL acyl chain composition. Currently, it is unclear how differing CL acyl chain composition utilizing liposomes will influence the cytochrome c form and function as a peroxidase. Thus, this study examined the role of CL acyl chain saturation within liposomes broadly reflecting the relative CL composition of mitochondrial membranes from healthy and dystrophic mouse muscle on cytochrome c conformation and function. Despite no differences in protein conformation or function between healthy and dystrophic liposomes, cytochrome c's affinity to CL increased with greater unsaturation. These findings suggest that increasing CL acyl chain saturation, as implicated in muscle wasting diseases, may not influence cytochrome c transformation and function as a peroxidase but may alter its interaction with CL, potentially impacting further downstream effects.
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Affiliation(s)
- Jennifer A Wilkinson
- Center for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Sebastian Silvera
- Center for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Paul J LeBlanc
- Center for Bone and Muscle Health, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
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2
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Kumar Sahoo D, Devi Tulsiyan K, Jena S, Biswal HS. Implication of Threonine-Based Ionic Liquids on the Structural Stability, Binding and Activity of Cytochrome c. Chemphyschem 2020; 21:2525-2535. [PMID: 33022820 DOI: 10.1002/cphc.202000761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/04/2020] [Indexed: 12/28/2022]
Abstract
Ionic liquids (ILs) are useful in pharmaceutical industries and biotechnology as alternative solvents or sources for protein extraction and purification, preservation of biomolecules and for regulating the catalytic activity of enzymes. However, the binding mechanism, the non-covalent forces responsible for protein-IL interactions and dynamics of proteins in IL need to be investigated in depth for the effective use of ILs as alternatives. Herein, we disclose the molecular level understanding of the structural intactness and reactivity of a model protein cytochrome c (Cyt c) in biocompatible threonine-based ILs with the help of experimental techniques such as isothermal titration calorimetry (ITC), fluorescence spectroscopy, transmission electron microscopy (TEM) as well as molecular docking. Hydrophobic and electrostatic forces are responsible for the structural and conformational integrity of Cyt c in IL. The ITC experiments revealed the Cyt c-IL binding free energies are in the range of 10-14 kJ/mol and the molecular docking studies demonstrated that ILs interact at the surfaces of Cyt c. The results look promising as the ILs used here are non-toxic and biocompatible, and thus may find potential applications in structural biology and biotechnology.
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Affiliation(s)
- Dipak Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN-752050, Bhubaneswar, India.,Homi Bhaba National Institute Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Kiran Devi Tulsiyan
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN-752050, Bhubaneswar, India.,Homi Bhaba National Institute Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Subhrakant Jena
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN-752050, Bhubaneswar, India.,Homi Bhaba National Institute Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Himansu S Biswal
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN-752050, Bhubaneswar, India.,Homi Bhaba National Institute Training School Complex, Anushakti Nagar, Mumbai, 400094, India
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3
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Ouyang X, Wang SY, Liu T, Ren YA, Wang MF, Chen FF, Wang LL. Functional modulation of cytochrome C upon specific binding to DNA nanoribbons. Chem Commun (Camb) 2019; 55:14074-14077. [PMID: 31696869 DOI: 10.1039/c9cc05427h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We discovered that the function of cytochrome C can be modulated by DNA nanoribbons. Meanwhile, the interplay between the DNA nanoribbons and the native cytochrome C and the possible mechanisms are also discussed.
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Affiliation(s)
- Xiangyuan Ouyang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Si-Yao Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Ting Liu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Yong-An Ren
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Mei-Fang Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Fang-Fang Chen
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
| | - Li-Li Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an, Shaanxi 710127, P. R. China.
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4
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Sahoo DK, Jena S, Tulsiyan KD, Dutta J, Chakrabarty S, Biswal HS. Amino-Acid-Based Ionic Liquids for the Improvement in Stability and Activity of Cytochrome c: A Combined Experimental and Molecular Dynamics Study. J Phys Chem B 2019; 123:10100-10109. [DOI: 10.1021/acs.jpcb.9b09278] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Dipak Kumar Sahoo
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Subhrakant Jena
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Kiran Devi Tulsiyan
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Juhi Dutta
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Suman Chakrabarty
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106, India
| | - Himansu S. Biswal
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), PO-Bhimpur-Padanpur, Via-Jatni, District- Khurda, PIN - 752050, Bhubaneswar, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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5
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Bihari M, Russell TP, Hoagland DA. Dissolution and dissolved state of cytochrome C in a neat, hydrophilic ionic liquid. Biomacromolecules 2010; 11:2944-8. [PMID: 20929217 DOI: 10.1021/bm100735z] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dissolution and dissolved molecular state of cytochrome c were investigated in the room temperature ionic liquid ethylmethylimidazolium ethylsulfate, [EMIM][EtSO4], by viscometry, optical and vibrational spectroscopies, and peroxidase activity. In dilute mixtures, viscometry demonstrated true molecular dissolution of cytochrome c in the ionic liquid and uncovered a molecular size larger than that in aqueous buffer, suggesting altered solvation or slight denaturation. The protein's heme unit absorbs light outside the spectral range masked by [EMIM], enabling conformational assessments by UV-visible and circular dichroism spectroscopies. Adding trends from fluorescence and Fourier transform infrared spectroscopy, unchanged secondary but perturbed tertiary structures were determined, consistent with the appreciable peroxidase activity measured. Different than in aqueous buffers, denaturation is not accompanied by aggregation. Results are relevant to the proposed application of ionic liquids as media for room temperature preservation of biomacromolecules.
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Affiliation(s)
- Malvika Bihari
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
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6
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Yari A, Abdoli HA. Sol-gel derived highly selective optical sensor for sensitive determination of the mercury(II) ion in solution. JOURNAL OF HAZARDOUS MATERIALS 2010; 178:713-717. [PMID: 20188463 DOI: 10.1016/j.jhazmat.2010.01.146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 01/28/2010] [Accepted: 01/29/2010] [Indexed: 05/28/2023]
Abstract
We report a versatile optical sensor by incorporating the indicator dye 4-phenyl-2,6-bis(2,3,5,6-tetrahydrobenzo[b][1,4,7]trioxononin-9-yl)pyrylium perchlorate into a sol-gel layer. The proposed optical sensor that is stable, fast and highly selective to Hg(2+) ions shows a significant absorbance signal change on exposure to an aqueous solution containing mercury(II) ion. The sensing film is able to determine mercury(II) ion in aqueous solution with a high selectivity over a wide dynamic range between 1.52x10(-9) and 1.70x10(-2)M, at pH 5, and a lower detection limit of 1.11x10(-9)M. Validation of the assay method revealed excellent performance characteristics for Hg(2+) ions over a wide variety of other metal ions, including good selectivity, long-term response stability and high reproducibility. Applications, for the direct determination of mercury(II) in real samples, gave the results with good correlation with the data obtained by using cold vapor atomic absorption spectrometry.
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Affiliation(s)
- Abdollah Yari
- Department of Chemistry, Lorestan University, Falakalaflak Street, 68178-17133 Khorramabad, Iran.
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Luo G, Zhang Q, Del Castillo AR, Urban V, O'Neill H. Characterization of sol-gel-encapsulated proteins using small-angle neutron scattering. ACS APPLIED MATERIALS & INTERFACES 2009; 1:2262-2268. [PMID: 20355861 DOI: 10.1021/am900430v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Entrapment of biomolecules in silica-derived sol-gels has grown into a vibrant area of research since it was originally demonstrated. However, accessing the consequences of entrapment on biomolecules and the gel structure remains a major challenge in characterizing these biohybrid materials. We present the first demonstration that it is possible with small-angle neutron scattering (SANS) to study the conformation of dilute proteins that are entrapped in transparent and dense sol-gels. Using deuterium-labeled green fluorescent protein (GFP) and SANS with contrast variation, we demonstrate that the scattering signatures of the sol-gel and the protein can be separated. Analysis of the scattering curves of the sol-gels using a mass-fractal model shows that the size of the colloidal silica particles and the fractal dimensions of the gels were similar in the absence and presence of protein, demonstrating that GFP did not influence the reaction pathway for the formation of the gel. The major structural difference in the gels was that the pore size was increased 2-fold in the presence of the protein. At the contrast match point for silica, the scattering signal from GFP inside the gel became distinguishable over a wide q range. Simulated scattering curves representing a monomer, end-to-end dimer, and parallel dimer of the protein were calculated and compared to the experimental data. Our results show that the most likely structure of GFP is that of an end-to-end dimer. This approach can be readily applied and holds great potential for the structural characterization of complex biohybrid and other materials.
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Affiliation(s)
- Guangming Luo
- Center for Structural Molecular Biology, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Wiederkehr RS, Hoops GC, Aslan MM, Byard CL, Mendes SB. Investigations on the Q and CT Bands of Cytochrome c Submonolayer Adsorbed on an Alumina Surface Using Broadband Spectroscopy with Single-Mode Integrated Optical Waveguides. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2009; 113:8306-8312. [PMID: 21289870 PMCID: PMC3031143 DOI: 10.1021/jp810845e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this work, we report experimental results on the molar absorptivity of cytochrome c adsorbed at different submonolayer levels onto an aluminum oxide waveguide surface; our data show a clear dependence of the protein optical properties on its surface density. The measurements were performed using the broadband, single-mode, integrated optical waveguide spectroscopic technique, which is an extremely sensitive tool able to reach submonolayer levels of detection required for this type of studies. This investigation focuses on the molar absorptivity at the Q-band (centered at 525 nm) and, for the first time to our knowledge, the weak charge transfer (CT) band (centered at 695 nm) of surface-adsorbed cyt c. Polarized light in the spectral region from 450 to 775 nm was all-coupled into an alumina thin film, which functioned as a single-mode planar optical waveguide. The alumina thin-film waveguide used for this work had a thickness of 180 nm and was deposited on a glass substrate by the atomic layer deposition process. The protein submonolayer was formed on the alumina waveguide surface through electrostatic adsorption from an aqueous buffer solution at neutral pH. The optical properties of the surface-adsorbed cyt c were investigated for bulk protein concentrations ranging from 5 nM to 8200 nM in the aqueous buffer solution. For a protein surface density of 2.3 pmol/cm(2), the molar absorptivity measured at the charge transfer band was 335 M(-1) cm(-1), and for a surface density of 15 pmol/cm(2) was 720 M(-1) cm(-1), which is much closer to the value of cyt c dissolved in an aqueous neutral buffer (830 M(-1) cm(-1)). The modification of the protein molar absorptivity and its dependence on the surface density can most likely be attributed to conformational changes of the surface-adsorbed species.
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Affiliation(s)
| | | | | | | | - Sergio B. Mendes
- Corresponding author. Phone: +1 502 852-0908. Fax: +1 502 852-8128.
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Kim S, Chung JK, Kwak K, Bowman SEJ, Bren KL, Bagchi B, Fayer MD. Native and unfolded cytochrome c--comparison of dynamics using 2D-IR vibrational echo spectroscopy. J Phys Chem B 2008; 112:10054-63. [PMID: 18646797 PMCID: PMC2671645 DOI: 10.1021/jp802246h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Unfolded vs native CO-coordinated horse heart cytochrome c (h-cyt c) and a heme axial methionine mutant cyt c552 from Hydrogenobacter thermophilus ( Ht-M61A) are studied by IR absorption spectroscopy and ultrafast 2D-IR vibrational echo spectroscopy of the CO stretching mode. The unfolding is induced by guanidinium hydrochloride (GuHCl). The CO IR absorption spectra for both h-cyt c and Ht-M61A shift to the red as the GuHCl concentration is increased through the concentration region over which unfolding occurs. The spectra for the unfolded state are substantially broader than the spectra for the native proteins. A plot of the CO peak position vs GuHCl concentration produces a sigmoidal curve that overlays the concentration-dependent circular dichroism (CD) data of the CO-coordinated forms of both Ht-M61A and h-cyt c within experimental error. The coincidence of the CO peak shift curve with the CD curves demonstrates that the CO vibrational frequency is sensitive to the structural changes induced by the denaturant. 2D-IR vibrational echo experiments are performed on native Ht-M61A and on the protein in low- and high-concentration GuHCl solutions. The 2D-IR vibrational echo is sensitive to the global protein structural dynamics on time scales from subpicosecond to greater than 100 ps through the change in the shape of the 2D spectrum with time (spectral diffusion). At the high GuHCl concentration (5.1 M), at which Ht-M61A is essentially fully denatured as judged by CD, a very large reduction in dynamics is observed compared to the native protein within the approximately 100 ps time window of the experiment. The results suggest the denatured protein may be in a glassy-like state involving hydrophobic collapse around the heme.
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Affiliation(s)
- Seongheun Kim
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Jean K. Chung
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Kyungwon Kwak
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Sarah E. J. Bowman
- Department of Chemistry, University of Rochester, Rochester, NY 14627-0216
| | - Kara L. Bren
- Department of Chemistry, University of Rochester, Rochester, NY 14627-0216
| | - Biman Bagchi
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - M. D. Fayer
- Department of Chemistry, Stanford University, Stanford, CA 94305
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Iafisco M, Palazzo B, Falini G, Foggia MD, Bonora S, Nicolis S, Casella L, Roveri N. Adsorption and conformational change of myoglobin on biomimetic hydroxyapatite nanocrystals functionalized with alendronate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:4924-4930. [PMID: 18373380 DOI: 10.1021/la703381h] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The chemical conjugation of bisphosphonates (BPs), specifically alendronate, to hydroxyapatite could be an effective means to impart to it fine-tuned bioactivity. Horse heart myoglobin (Mb), a well-characterized protein, has been adsorbed onto biomimetic hydroxyapatite nanocrystals (nHA) and onto the nHA/alendronate conjugate powdered samples. The obtained materials have potential use in bone implantation and as prospective drug-delivery devices. The kinetic absorption of Mb onto nHA is dramatically affected by its functionalization with alendronate. The covering of the nHA surface by alendronate inhibits the adsorption of myoglobin. The adsorption mechanisms of the protein were studied by spectroscopic techniques (UV-vis and surface-enhanced Raman spectroscopy). The results indicate that the protein changes conformation upon adsorption on the inorganic substrate. In particular, the interaction with nHA alters the coordination state of the iron in the heme through the formation of a hexacoordinated low-spin Mb heme, possibly involving the distal histidine. Instead, the covering of the nHA surface by alendronate does not adsorb the protein but preserves the coordination state of the heme moiety. This study could be of significance either in the field of biomaterials science, in particular, to fine tune a bone-specific drug delivery device and to test nHA as a new support for heterogeneous catalysis, improving the understating of enzyme immobilization.
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Affiliation(s)
- Michele Iafisco
- Dipartimento di Chimica G. Ciamician, Alma Mater Studiorum Università di Bologna, Via Selmi 2, 40126 Bologna, Italy
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11
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Shibayama N. Slow Motion Analysis of Protein Folding Intermediates within Wet Silica Gels. Biochemistry 2008; 47:5784-94. [DOI: 10.1021/bi8003582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Naoya Shibayama
- Department of Physiology, Division of Biophysics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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Yeh HC, Hsu PY, Tsai AL, Wang LH. Spectroscopic characterization of the oxyferrous complex of prostacyclin synthase in solution and in trapped sol-gel matrix. FEBS J 2008; 275:2305-14. [PMID: 18397321 DOI: 10.1111/j.1742-4658.2008.06385.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prostacyclin synthase (PGIS) is a member of the cytochrome P450 family in which the oxyferrous complexes are generally labile in the absence of substrate. At 4 degrees C, the on-rate constants and off-rate constants of oxygen binding to PGIS in solution are 5.9 x 10(5) m(-1).s(-1) and 29 s(-1), respectively. The oxyferrous complex decays to a ferric form at a rate of 12 s(-1). We report, for the first time, a stable oxyferrous complex of PGIS in a transparent sol-gel monolith. The encapsulated ferric PGIS retained the same spectroscopic features as in solution. The binding capabilities of the encapsulated PGIS were demonstrated by spectral changes upon the addition of O-based, N-based and C-based ligands. The peroxidase activity of PGIS in sol-gel was three orders of magnitude slower than that in solution owing to the restricted diffusion of the substrate in sol-gel. The oxyferrous complex in sol-gel was observable for 24 h at room temperature and displayed a much red-shifted Soret peak. Stabilization of the ferrous-carbon monoxide complex in sol-gel was observed as an enrichment of the 450-nm species over the 420-nm species. This result suggests that the sol-gel method may be applied to other P450s to generate a stable intermediate in the di-oxygen activation.
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Affiliation(s)
- Hui-Chun Yeh
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center, Houston, TX 77030, USA
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Deriu D, Pagnotta SE, Santucci R, Rosato N. Spectroscopic and electrochemical characterization of cytochrome c encapsulated in a bio sol–gel matrix. Biometals 2007; 21:417-23. [DOI: 10.1007/s10534-007-9130-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 12/10/2007] [Indexed: 12/01/2022]
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