Structural and redox properties of mitochondrial cytochrome c co-sorbed with phosphate on hematite (α-Fe2O3) surfaces
| Autor: | Carrick M. Eggleston, Steven W. Boese, David M. Lovelace, Nidhi Khare |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Cytochrome
Surface Properties Static Electricity Inorganic chemistry Microscopy Atomic Force Ferric Compounds environment and public health Redox Absorption Phosphates Biomaterials chemistry.chemical_compound Colloid and Surface Chemistry Native state Animals Horses Heme biology Chemistry Myocardium Cytochrome c Cytochromes c Hydrogen-Ion Concentration Hematite Phosphate Mitochondria Surfaces Coatings and Films Electronic Optical and Magnetic Materials enzymes and coenzymes (carbohydrates) Crystallography Isoelectric point visual_art embryonic structures cardiovascular system biology.protein visual_art.visual_art_medium Oxidation-Reduction |
| Zdroj: | Journal of Colloid and Interface Science. 303:404-414 |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/j.jcis.2006.07.070 |
| Popis: | The interaction of metalloproteins with oxides has implications not only for bioanalytical systems and biosensors but also in the areas of biomimetic photovoltaic devices, bioremediation, and bacterial metal reduction. Here, we investigate mitochondrial ferricytochrome c (Cyt c) co-sorption with 0.01 and 0.1 M phosphate on hematite (alpha-Fe2O3) surfaces as a function of pH (2-11). Although Cyt c sorption to hematite in the presence of phosphate is consistent with electrostatic attraction, other forces act upon Cyt c as well. The occurrence of multilayer adsorption, and our AFM observations, suggest that Cyt c aggregates as the pH approaches the Cyt c isoelectric point. In solution, methionine coordination of heme Fe occurs only between pH 3 and 7, but in the presence of phosphate this coordination is retained up to pH 10. Electrochemical evidence for the presence of native Cyt c occurs down to pH 3 and up to pH 10 in the absence of phosphate, and this range is extended to pH 2 and 11 in the presence of phosphate. Cyt c that initially adsorbs to a hematite surface may undergo conformation change and coat the surface with unfolded protein such that subsequently adsorbing protein is more likely to retain the native conformational state. AFM provides evidence for rapid sorption kinetics for Cyt c co-sorbed with 0.01 or 0.1 M phosphate. Cyt c co-sorbed with 0.01 M phosphate appears to unfold on the surface of hematite while Cyt c co-sorbed with 0.1 M phosphate possibly retains native conformation due to aggregation. |
| Databáze: | OpenAIRE |
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