Abstract:

Conformational transitions of oxidized and reduced cytochrome c at various solvent conditions are summarized. Sorbitol stabilizes and NaCl destabilizes native cytochrome c structure against the acid denaturation. In the process of heating, NaCl more strongly stabilizes molten globular cytochtome c state than sorbitol in secondary structure region, but in heme region, sorbitol is stronger stabilizer of cytochrome c molten globular state than NaCl. In the presence of strong inorganic acids H₂SO₄ and HClO₄ and their salts two low spin and one high-spin heme conformers occur. The unstable pentacoordinated conformer is formed in 8M H₂SO₄. Cytochrome c creates complexes with polyanions poly(vynilsulfate) and poly(4-styrene-sulfonate), which are able to mimic the effect of cytochrome c natural redox partner on its structure, as well as to prevent its the aggregation in aggregation prone conditions. Cytochrome c forms complexes with gold nanoparticles covered by glutation, which enhance stability in heme region at room temperature.