Met-myoglobin Association in Dilute Solution during Pressure-Induced Denaturation: an Analysis at pH 4.5 by High-Pressure Small-Angle X-ray Scattering
| Autor: | Cinelli S, Onori G, F. Carsughi, Saturni L, Paolo Mariani, Sigrid Bernstorff, Francesco Spinozzi |
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| Rok vydání: | 2007 |
| Předmět: |
STRUCTURAL-CHARACTERIZATION
Protein Denaturation Analytical chemistry law.invention chemistry.chemical_compound X-Ray Diffraction law Scattering Small Angle COLD-DENATURATION Pressure Materials Chemistry Denaturation (biochemistry) Physical and Theoretical Chemistry MOLTEN GLOBULE Scattering Small-angle X-ray scattering Form factor (quantum field theory) Hydrogen-Ion Concentration Synchrotron Surfaces Coatings and Films Solutions BIOLOGICAL MACROMOLECULES HYDROSTATIC-PRESSURE Models Chemical Myoglobin chemistry Thermodynamics Hydrostatic equilibrium Metmyoglobin Dimerization Bar (unit) |
| Zdroj: | 111 (2007): 3822–3830. info:cnr-pdr/source/autori:Spinozzi, F; Mariani, P; Saturni, L; Carsughi, F; Bernstorff, S; Cinelli, S; Onori, G/titolo:Met-myoglobin association in dilute solution during pressure-induced denaturation: An analysis at pH 4.5 by high-pressure small-angle X-ray scattering/doi:/rivista:/anno:2007/pagina_da:3822/pagina_a:3830/intervallo_pagine:3822–3830/volume:111 |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | In this paper, we report on the original global fit procedure of synchrotron small-angle X-ray scattering (SAXS) data applied to a model protein, met-myoglobin, in dilute solution during temperature- and pressure-induced denaturation processes at pH 4.5. Starting from the thermodynamic description of the protein unfolding pathway developed by Hawley (Hawley, S. A. Biochemistry 1971, 10, 2436), we have developed a new method for analyzing the set of SAXS curves using a global fitting procedure, which allows us to derive the form factor of all the met-myoglobin species present in the solution, their aggregation state, and the set of thermodynamic parameters, with their p and T dependence. This method also overcomes a reasonably poor quality of the experimental data, and it is found to be very powerful in analyzing SAXS data. SAXS experiments were performed at four different temperatures from hydrostatic pressures up to about 2000 bar. As a result, the presence of an intermediate, partially unfolded, dimeric state of met-myoglobin that forms during denaturation has been evidenced. The obtained parameters were then used to derive the met-myoglobin p, T phase diagram that fully agrees with the corresponding phase diagram obtained by spectroscopic measurements. |
| Databáze: | OpenAIRE |
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