A globular high spin form of ferricytochrome c. J Biol Chem 1983 Jun 10;258(11):6772-6
Date
06/10/1983Pubmed ID
6304055Scopus ID
2-s2.0-0021099620 (requires institutional sign-in at Scopus site) 44 CitationsAbstract
Acidification of a salt-free solution of native low spin globular horse heart ferricytochrome c with HCl causes a single cooperative transition centered at pH 2.5 at 23 degrees C resulting in the formation of denatured high spin ferricytochrome c. By contrast, acidification with HCIO4 uncouples denaturation from the spin-state transition, resulting in the formation of a globular high spin form of ferricytochrome c at pH 0.0 exhibiting only modest conformational differences from native cytochrome c as judged by far ultraviolet circular dichoroic, tryptophan fluorescence, and reduced viscosity measurements. This uncoupling is consistent with the preferential binding of two perchlorate anions to the globular form(s) cytochrome c. The acid spin-state transition of the perchlorate complex is biphasic, having midpoint values at pH 0.7 and 3.6 involving 1.0 and 1.6 protons, respectively, when measured in the presence of 1 M perchlorate.
Author List
Robinson JB Jr, Strottmann JM, Stellwagen EAuthor
James M. Strottmann MD Associate Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCircular Dichroism
Cytochrome c Group
Horses
Hydrogen-Ion Concentration
Kinetics
Myocardium
Porphyrins
Protein Conformation
Spectrophotometry
