Conformational Transitions of Ferricytochrome c in Strong Inorganic Acids

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Title:Conformational Transitions of Ferricytochrome c in Strong Inorganic Acids
Creators:
Stupák, Marek
Bágeľová, Jaroslava
Fedunová, Diana
Antalík, Marián
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 71, 11-12, pp. 1627-1641
Uncontrolled Keywords:MCD, CD, Protein structure, Absorption spectroscopy, Ferricytochrome <i>c</i>, Conformational transitions, Heme ligands

Abstract

Conformational transitions of horse heart ferricytochrome <i>c</i> (ferricyt <i>c</i>) have been investigated in the presence of strong inorganic acids and their salts by optical absorption spectroscopy, magnetic circular dichroism and circular dichroism. In the presence of acids (HClO<sub>4</sub> or H<sub>2</sub>SO<sub>4</sub>, pH 2) or their salts (1 M NaClO<sub>4</sub> or Na<sub>2</sub>SO<sub>4</sub>, pH 2, 25 °C), the three ligation states of ferricyt <i>c</i> heme were identified. One is the high-spin state: His18-Fe-H<sub>2</sub>O (40-50%), and two are the low-spin states: His18-Fe-Met80 (30-25%) and His18-Fe-His (30-25%). Under these conditions low temperatures facilitate native heme coordination of ferricyt <i>c</i>. Transition from low-spin to high-spin heme coordination of ferricyt <i>c</i> is complete in 1 M HClO<sub>4</sub> or 3 M H<sub>2</sub>SO<sub>4</sub>. At the concentration of HClO<sub>4</sub> and H<sub>2</sub>SO<sub>4 </sub>above 3 M, different behavior in spectral transitions of ferricyt <i>c</i> near the heme is observed. High-spin pentacoordinated ferricyt <i>c</i> with the heme ligand of His18-Fe is formed in 8 M H<sub>2</sub>SO<sub>4</sub>. This state is unstable at higher concentration of H<sub>2</sub>SO<sub>4</sub> and porphyrin ferricyt <i>c</i> is formed. At HClO<sub>4 </sub>concentration higher than 3 M, the new, until this time not observed heme coordination structure of ferricyt <i>c</i> originates. <p>

Title:Conformational Transitions of Ferricytochrome c in Strong Inorganic Acids
Creators:
Stupák, Marek
Bágeľová, Jaroslava
Fedunová, Diana
Antalík, Marián
Uncontrolled Keywords:MCD, CD, Protein structure, Absorption spectroscopy, Ferricytochrome <i>c</i>, Conformational transitions, Heme ligands
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:71
Number:11-12
Page Range:pp. 1627-1641
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20061627UNSPECIFIED
ID Code:2566
Item Type:Article
Deposited On:06 Feb 2009 17:19
Last Modified:06 Feb 2009 16:19

Citation

Stupák, Marek; Bágeľová, Jaroslava; Fedunová, Diana; Antalík, Marián (2006) Conformational Transitions of Ferricytochrome c in Strong Inorganic Acids. Collection of Czechoslovak Chemical Communications, 71 (11-12). pp. 1627-1641. ISSN 0010-0765

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