| |
Records |
Links |
|
Author |
Tsong, T.Y. |
|
| |
Title |
Conformational relaxations of urea- and guanidine hydrochloride-unfolded ferricytochrome c |
Type |
Journal Article |
| |
Year |
1977 |
Publication |
The Journal of Biological Chemistry |
Abbreviated Journal  |
J Biol Chem |
|
| |
Volume |
252 |
Issue |
24 |
Pages |
8778-8780 |
|
| |
Keywords |
*Cytochrome c Group; Guanidines/*pharmacology; Protein Conformation/drug effects; Spectrometry, Fluorescence; Urea/*pharmacology |
|
| |
Abstract |
Several recent studies of protein the unfolded proteins. In urea- and guanidine HCl-unfolded ferricytochrome c (horse heart), an acid-induced spin state transformation of the heme group has been detected by the heme absorptions, Trp-59 fluorescence, and the intrinsic viscosity of protein. Kinetics of this second conformational transition, by the temperature jump and stopped flow methods, are complex. One rapid reaction (tau1), pH-independent, occurs in a 50-mus range; the second reaction (tau2), in a 1-ms range, depends linearly upon pH and is faster at the alkaline side; a third reaction (tau3), in a 1-s range, shows a sigmoidal transition at pH 5.1 and is faster at the acidic side. The results are consistent with a kinetic scheme which involves protein conformational changes in the transformation of the heme coordination state. The kinetics, along with previous equilibrium studies, indicate that ligand or charge interactions within a protein molecule are not completely prohibited even in strongly denaturing conditions, such as in high concentrations of urea and guanidine HCl. Thus, local structures of peptide chain associated with these interactions can exist in the unfolded protein. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9258 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:200618 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3882 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wilson, M.T.; Silvestrini, M.C.; Morpurgo, L.; Brunori, M. |
|
| |
Title |
Electron transfer kinetics between Rhus vernicifera stellacyanin and cytochrome c (horse heart cytochrome c and Pseudomonas cytochrome c551) |
Type |
Journal Article |
| |
Year |
1979 |
Publication |
Journal of Inorganic Biochemistry |
Abbreviated Journal |
J Inorg Biochem |
|
| |
Volume |
11 |
Issue |
2 |
Pages |
95-100 |
|
| |
Keywords |
Animals; Copper; Cytochrome c Group/*metabolism; Electron Transport; Kinetics; Metalloproteins/*metabolism; Plant Proteins/*metabolism; *Plants, Toxic; Pseudomonas aeruginosa/*metabolism; Toxicodendron/*metabolism |
|
| |
Abstract |
The electron transfer reactions between Rhus vernicifera stellacyanin and either horse heart cytochrome c or Pseudomonas aeruginosa cytochrome c551 were investigated by rapid reaction techniques. The time course of electron transfer is monophasic under all conditions, and thus consistent with a simple formulation of the reaction. Both stopped-flow and temperature-jump experiments yield equilibrium constants in reasonable agreement with values calculated from the redox potentials. The differences in reaction rate between the two cytochromes and stellacyanin are discussed in terms of the Marcus theory. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0162-0134 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:228006 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3879 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hoang, L.; Maity, H.; Krishna, M.M.G.; Lin, Y.; Englander, S.W. |
|
| |
Title |
Folding units govern the cytochrome c alkaline transition |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
|
| |
Volume |
331 |
Issue |
1 |
Pages |
37-43 |
|
| |
Keywords |
Animals; Cytochrome c Group/*chemistry; Horses; Hydrogen/chemistry; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; *Protein Folding; Protein Structure, Tertiary; Spectrum Analysis; Titrimetry |
|
| |
Abstract |
The alkaline transition of cytochrome c is a model for protein structural switching in which the normal heme ligand is replaced by another group. Stopped flow data following a jump to high pH detect two slow kinetic phases, suggesting two rate-limiting structure changes. Results described here indicate that these events are controlled by the same structural unfolding reactions that account for the first two steps in the reversible unfolding pathway of cytochrome c. These and other results show that the cooperative folding-unfolding behavior of protein foldons can account for a variety of functional activities in addition to determining folding pathways. |
|
| |
Address |
Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6059, USA. lhoang@mail.upenn.edu |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-2836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:12875834 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3781 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hagen, S.J.; Eaton, W.A. |
|
| |
Title |
Two-state expansion and collapse of a polypeptide |
Type |
Journal Article |
| |
Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
|
| |
Volume |
301 |
Issue |
4 |
Pages |
1019-1027 |
|
| |
Keywords |
Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics |
|
| |
Abstract |
The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse. |
|
| |
Address |
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-2836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:10966803 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3790 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Pierce, M.M.; Nall, B.T. |
|
| |
Title |
Coupled kinetic traps in cytochrome c folding: His-heme misligation and proline isomerization |
Type |
Journal Article |
| |
Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
|
| |
Volume |
298 |
Issue |
5 |
Pages |
955-969 |
|
| |
Keywords |
Amino Acid Sequence; Amino Acid Substitution/genetics; Binding Sites; Cytochrome c Group/*chemistry/genetics/*metabolism; *Cytochromes c; Enzyme Stability/drug effects; Fluorescence; Guanidine/pharmacology; Heme/*metabolism; Histidine/genetics/*metabolism; Hydrogen-Ion Concentration; Isomerism; Kinetics; Models, Molecular; Molecular Sequence Data; Mutation/genetics; Proline/*chemistry/metabolism; Protein Conformation/drug effects; Protein Denaturation/drug effects; *Protein Folding; Protein Renaturation; Saccharomyces cerevisiae/enzymology/genetics; Sequence Alignment; Thermodynamics |
|
| |
Abstract |
The effect of His-heme misligation on folding has been investigated for a triple mutant of yeast iso-2 cytochrome c (N26H,H33N,H39K iso-2). The variant contains a single misligating His residue at position 26, a location at which His residues are found in several cytochrome c homologues, including horse, tuna, and yeast iso-1. The amplitude for fast phase folding exhibits a strong initial pH dependence. For GdnHCl unfolded protein at an initial pH<5, the observed refolding at final pH 6 is dominated by a fast phase (tau(2f)=20 ms, alpha(2f)=90 %) that represents folding in the absence of misligation. For unfolded protein at initial pH 6, folding at final pH 6 occurs in a fast phase of reduced amplitude (alpha(2f) approximately 20 %) but the same rate (tau(2f)=20 ms), and in two slower phases (tau(m)=6-8 seconds, alpha(m) approximately 45 %; and tau(1b)=16-20 seconds, alpha(1b) approximately 35 %). Double jump experiments show that the initial pH dependence of the folding amplitudes results from a slow pH-dependent equilibrium between fast and slow folding species present in the unfolded protein. The slow equilibrium arises from coupling of the His protonation equilibrium to His-heme misligation and proline isomerization. Specifically, Pro25 is predominantly in trans in the unligated low-pH unfolded protein, but is constrained in a non-native cis isomerization state by His26-heme misligation near neutral pH. Refolding from the misligated unfolded form proceeds slowly due to the large energetic barrier required for proline isomerization and displacement of the misligated His26-heme ligand. |
|
| |
Address |
Center for Biomolecular Structure, Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-2836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:10801361 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3853 |
|
| Permanent link to this record |
