Abstract
AbstractAbsorbance‐detected thermal denaturation studies of the C102T variant of Saccharomyces cerevisiae iso‐1‐ferricytochrome c were performed between pH 3 and 5. Thermal denaturation in this pH range is reversible, shows no concentration dependence, and is consistent with a 2‐state model. Values for free energy (ΔGD), enthalpy (ΔHD), and entropy (ΔSD) of denaturation were determined as functions of pH and temperature. The value of ΔGD at 300 K, pH 4.6, is 5.1 ± 0.3 kcal mol−1. The change in molar heat capacity upon denaturation (ΔCp), determined by the temperature dependence of ΔHD as a function of pH (1.37 ± 0.06 kcal mol−1 K−1), agrees with the value determined by differential scanning calorimetry. pH‐dependent changes in the Soret region indicate that a group or groups in the heme environment of the denatured protein, probably 1 or both heme propionates, ionize with a pK near 4. The C102T variant exhibits both enthalpy and entropy convergence with a ΔHD of 1.30 kcal mol−1 residue−1 at 373.6 K and a ΔSD of 4.24 cal mol−1 K−1 residue−1 at 385.2 K. These values agree with those for other single‐domain, globular proteins.
References
49
Referenced
64
10.1126/science.181.4096.223
10.1021/bi00099a028
10.1002/pro.5560021218
10.1073/pnas.83.21.8069
10.1002/bip.360261104
10.1016/0022-2836(92)90255-I
10.1021/bi00164a007
10.1016/0959-440X(93)90090-8
10.1021/ja00043a062
10.1016/S0959-440X(05)80118-6
10.1016/S0021-9258(20)79752-8
/ J Biol Chem / Nuclear magnetic resonance titration curves of histidine ring protons by Cohen JS (1974)10.1093/protein/1.2.95
10.1021/bi00483a001
10.1146/annurev.bi.60.070191.004051
10.1021/bi00154a007
10.1016/S0021-9258(19)39863-1
/ J Biol Chem / Differential stability of two apo‐isocytochromes c in the yeast Saccharomyces cerevisiae by Dumont MD (1990){'key': 'e_1_2_1_18_1', 'first-page': '452', 'volume-title': 'Biophysical chemistry', 'author': 'Edsall JT', 'year': '1958'}
/ Biophysical chemistry by Edsall JT (1958)10.1016/0005-2795(77)90166-0
10.1021/bi00054a026
10.1073/pnas.89.19.9335
10.1021/bi00221a028
10.1021/bi00482a007
10.1016/0162-0134(93)85038-A
10.1042/bj2580595
/ Biochem J / A denaturation‐induced proton‐uptake study of horse cytochrome c by Hartshorn RT (1988)10.1021/ja00086a046
10.1021/ja01476a025
10.1016/0162-0134(93)85036-8
10.1016/S0021-9258(18)48213-0
/ J Biol Chem / Replacement of the invariant lysine 77 by arginine in yeast iso‐1‐cytochrome c results in enhanced and normal activities in vitro and in vivo by Holzschu D (1987)10.1016/S0021-9258(19)46967-6
/ J Biol Chem / Mutagenesis at a specific position in a DNA sequence by Hutchinson CA (1978)10.1016/S0065-3233(08)60608-7
10.1042/bj2990347
/ Biochem J / The significance of denaturant titrations of protein stability: A comparison of rat and baker's yeast cytochrome c and their site‐directed asparagine‐52‐to‐isoleucine mutants by Koshy TI (1994)10.1002/bip.1966.360040808
10.1002/pro.5560021204
{'key': 'e_1_2_1_35_1', 'first-page': '1966', 'article-title': 'Amide proton exchange rates of oxidized and reduced Saccharomyces cerevisiae iso‐1‐cytochrome c Protein', 'volume': '2', 'author': 'Marmorino JL', 'year': '1993', 'journal-title': 'Sci'}
/ Sci / Amide proton exchange rates of oxidized and reduced Saccharomyces cerevisiae iso‐1‐cytochrome c Protein by Marmorino JL (1993)10.1007/978-3-642-74536-2
10.1016/0022-2836(91)90506-2
10.1016/B978-0-12-058757-5.50060-3
{'key': 'e_1_2_1_39_1', 'first-page': '311', 'volume-title': 'Protein structure: A practical approach', 'author': 'Pace CN', 'year': '1990'}
/ Protein structure: A practical approach by Pace CN (1990)10.1007/978-3-642-72698-9
10.1016/0301-4622(76)80005-1
10.1016/B978-1-4831-9718-0.50010-2
10.1016/S0065-3233(08)60377-0
10.1016/0022-2836(74)90188-0
10.1006/jmbi.1993.1417
10.1002/bip.1969.360080502
10.1002/bip.1969.360070402
10.1016/0092-8674(79)90091-6
10.1021/bi00388a026
10.1021/bi00080a025
Dates
Type | When |
---|---|
Created | 16 years, 6 months ago (Feb. 9, 2009, 9 p.m.) |
Deposited | 1 year, 10 months ago (Oct. 24, 2023, 2:17 a.m.) |
Indexed | 1 month, 3 weeks ago (July 4, 2025, 7:48 a.m.) |
Issued | 31 years ago (Aug. 1, 1994) |
Published | 31 years ago (Aug. 1, 1994) |
Published Online | 16 years, 7 months ago (Dec. 31, 2008) |
Published Print | 31 years ago (Aug. 1, 1994) |
@article{Cohen_1994, title={Stability of yeast iso‐1‐ferricytochrome c as a function of pH and temperature}, volume={3}, ISSN={1469-896X}, url={http://dx.doi.org/10.1002/pro.5560030811}, DOI={10.1002/pro.5560030811}, number={8}, journal={Protein Science}, publisher={Wiley}, author={Cohen, David S. and Pielak, Gary J.}, year={1994}, month=aug, pages={1253–1260} }