Dissociation Constants of Protonated Oxidized Glutathione in Seawater Media at Different Salinities Academic Article

abstract

• Oxidized glutathione (GSSG), which has four carboxylic and two amino groups, interacts with metal ions and may affect the bioavailability and geochemistry of metals in natural waters. In the present paper, six stepwise protonation constants KiH for GSSG were measured as a function of salinity, S = 5-35 at t = 25C (and in NaCl/MgCl2 mixtures at different ionic strengths), in order to provide thermodynamic data for their acid base properties, which are useful for studying the interaction with metals in these media. The protonation enthalpies (Hi/kJ mol-1) were also determined at t = 25C. The results were interpreted using the SIT model and Pitzer equations. The seawater model with the interaction parameters accounts for the differences between the values in NaCl and seawater. The results suggest that it is important to consider all of the ionic interactions in natural waters in examining the proton dissociation of GSSG. Springer Science+Business Media B.V. 2010.

authors

• Sharma, Virender

published proceedings

• AQUATIC GEOCHEMISTRY

author list (cited authors)

• Crea, P., De Stefano, C., Millero, F. J., Sammartano, S., & Sharma, V. K.

citation count

• 12

complete list of authors

• Crea, Pasquale||De Stefano, Concetta||Millero, Frank J||Sammartano, Silvio||Sharma, Virender K

publication date

• June 2010

publisher

• Springer Nature  Publisher

published in

• AQUATIC GEOCHEMISTRY  Journal

keywords

• Medium Effects
• Oxidized Glutathione
• Pitzer Coefficients
• Protonation Constants
• SIT Model
• Synthetic Seawater

Digital Object Identifier (DOI)

• 10.1007/s10498-010-9093-0

start page

• 447

end page

• 466

volume

• 16

issue

• 3

URL

• http://dx.doi.org/10.1007/s10498-010-9093-0