Abstract
We determined the pKa values of acidic residues in hen lysozyme by comparing the pH dependency of stability between wild type and mutant lysozymes in which a negative charge is eliminated. In the comparison of the stability between wild type and a mutant lysozyme, the difference in pH titration curve between them could be expressed as a two-state process involving protonation of a single acidic residue. The results strongly indicated that the Aune and Tanford theory of protein denaturation [Aune, K.C. and Tanford, C. (1969) Biochemistry 8, 4579-4585] is applicable to protein stability in solution. On the other hand, the pKa values of acidic residues in the presence of low (5 mM) or high (400 mM) salt concentration were determined by means of two-dimensional NMR. We found that the pKa values obtained from the pH dependency of stability were close to those from the NMR experiment under the high salt condition. Moreover, by comparing pKa values at high salt and low salt concentrations, we could evaluate the dependency of two electrostatic interactions (salt bridge and charge-helix dipole interaction) on salt concentration.
| Original language | English |
|---|---|
| Pages (from-to) | 946-952 |
| Number of pages | 7 |
| Journal | Journal of Biochemistry |
| Volume | 118 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Oct 1 1995 |
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All Science Journal Classification (ASJC) codes
- Biochemistry
- Molecular Biology
Cite this
Effect of salt concentration on the pKa of acidic residues in lysozyme. / Abe, Yoshito; Ueda, Tadashi; Iwashita, Hiroki; Hashimoto, Yoshio; Motoshima, Hiroyuki; Tanaka, Yoshitugu; Imoto, Taiji.
In: Journal of Biochemistry, Vol. 118, No. 5, 01.10.1995, p. 946-952.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of salt concentration on the pKa of acidic residues in lysozyme
AU - Abe, Yoshito
AU - Ueda, Tadashi
AU - Iwashita, Hiroki
AU - Hashimoto, Yoshio
AU - Motoshima, Hiroyuki
AU - Tanaka, Yoshitugu
AU - Imoto, Taiji
PY - 1995/10/1
Y1 - 1995/10/1
N2 - We determined the pKa values of acidic residues in hen lysozyme by comparing the pH dependency of stability between wild type and mutant lysozymes in which a negative charge is eliminated. In the comparison of the stability between wild type and a mutant lysozyme, the difference in pH titration curve between them could be expressed as a two-state process involving protonation of a single acidic residue. The results strongly indicated that the Aune and Tanford theory of protein denaturation [Aune, K.C. and Tanford, C. (1969) Biochemistry 8, 4579-4585] is applicable to protein stability in solution. On the other hand, the pKa values of acidic residues in the presence of low (5 mM) or high (400 mM) salt concentration were determined by means of two-dimensional NMR. We found that the pKa values obtained from the pH dependency of stability were close to those from the NMR experiment under the high salt condition. Moreover, by comparing pKa values at high salt and low salt concentrations, we could evaluate the dependency of two electrostatic interactions (salt bridge and charge-helix dipole interaction) on salt concentration.
AB - We determined the pKa values of acidic residues in hen lysozyme by comparing the pH dependency of stability between wild type and mutant lysozymes in which a negative charge is eliminated. In the comparison of the stability between wild type and a mutant lysozyme, the difference in pH titration curve between them could be expressed as a two-state process involving protonation of a single acidic residue. The results strongly indicated that the Aune and Tanford theory of protein denaturation [Aune, K.C. and Tanford, C. (1969) Biochemistry 8, 4579-4585] is applicable to protein stability in solution. On the other hand, the pKa values of acidic residues in the presence of low (5 mM) or high (400 mM) salt concentration were determined by means of two-dimensional NMR. We found that the pKa values obtained from the pH dependency of stability were close to those from the NMR experiment under the high salt condition. Moreover, by comparing pKa values at high salt and low salt concentrations, we could evaluate the dependency of two electrostatic interactions (salt bridge and charge-helix dipole interaction) on salt concentration.
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UR - http://www.scopus.com/inward/citedby.url?scp=0028799099&partnerID=8YFLogxK
U2 - 10.1093/jb/118.5.946
DO - 10.1093/jb/118.5.946
M3 - Article
VL - 118
SP - 946
EP - 952
JO - Journal of Biochemistry
JF - Journal of Biochemistry
SN - 0021-924X
IS - 5
ER -