TY - JOUR
T1 - Effect of ionic strength and temperature on the protonation of oxidized glutathione
AU - Crea, Pasquale
AU - De Stefano, Concetta
AU - Kambarami, Mutsa
AU - Millero, Frank J.
AU - Sharma, Virender K.
N1 - Funding Information:
Acknowledgements FJM wishes to acknowledge the support of the Oceanographic Section of the National Science Foundation and National Oceanic and Atmospheric Administration for supporting his Marine Physical Chemistry research. CD and PC thank the University of Messina for financial support.
PY - 2008/9
Y1 - 2008/9
N2 - 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).
AB - 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).
KW - Ionic strength
KW - Oxidized glutathione
KW - Pitzer coefficients
KW - Protonation constants
KW - SIT model
KW - Sodium chloride
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U2 - 10.1007/s10953-008-9310-2
DO - 10.1007/s10953-008-9310-2
M3 - Article
AN - SCOPUS:48749103776
VL - 37
SP - 1245
EP - 1259
JO - Journal of Solution Chemistry
JF - Journal of Solution Chemistry
SN - 0095-9782
IS - 9
ER -