Abstract
The protonation constants for oxidized glutathione, Hi-1L (4-i+1)-, KiH =[HiL (4-i)-]/[Hi-1L(4-i+1)-][H+] i=1,2,...,6 have been measured at 5, 25 and 45°C as a function of the ionic strength (0.1 to 5.4 mol·[kg(H2O)]-1) in NaCl solutions. The effect of ionic strength on the measured protonation constants has been used to determine the thermodynamic values (KiH0 ) and the enthalpy (ΔHi ) for the dissociation reaction using the SIT model and Pitzer equations. The SIT (ε) and Pitzer parameters (β(0), β(1) and C) for the dissociation products (L4-, HL3-, H2L2-, H 3L-, H4L, H5L+, H 6L2+) have been determined as a function of temperature. These results can be used to examine the effect of ionic strength and temperature on glutathione in aqueous solutions with NaCl as the major component (body fluids, seawater and brines).
Original language | English (US) |
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Pages (from-to) | 1245-1259 |
Number of pages | 15 |
Journal | Journal of Solution Chemistry |
Volume | 37 |
Issue number | 9 |
DOIs | |
State | Published - Sep 1 2008 |
Keywords
- Ionic strength
- Oxidized glutathione
- Pitzer coefficients
- Protonation constants
- SIT model
- Sodium chloride
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Physical and Theoretical Chemistry