protonation equilibria of selected glycine dipeptides in ethanol-water mixture: solvent composition effect

Knowledge of the protonation constants of small dipeptide is important, interesting and necessary for complete understanding of the physiochemical behavior of dipeptide. In this study, the protonation constants of some aliphatic dipeptides (Gly-Gly, Gly-Val, Gly-Leu, Gly-Thr, Gly-Phe and Gly-Met) we...

Full description

Saved in:
Bibliographic Details
Published in:Amino acids 2009-02, Vol.36 (2), p.373-379
Main Authors: Doğan, Alev, Ozel, Ayça Demirel, Kiliç, Esma
Format: Article
Language:English
Subjects:
Analytical Chemistry
Biochemical Engineering
Biochemistry
Biomedical and Life Sciences
Dipeptides - chemistry
Ethanol
Ethanol - chemistry
Glycine - chemistry
Life Sciences
Neurobiology
Proteomics
Protons
Short Communication
Solvents - chemistry
Studies
Water - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Knowledge of the protonation constants of small dipeptide is important, interesting and necessary for complete understanding of the physiochemical behavior of dipeptide. In this study, the protonation constants of some aliphatic dipeptides (Gly-Gly, Gly-Val, Gly-Leu, Gly-Thr, Gly-Phe and Gly-Met) were studied in water and ethanol-water mixtures [20% ethanol-80% water, 40% ethanol-60% water, 60% ethanol-40% water, (v/v)] at 25 ± 0.1°C under nitrogen atmosphere and ionic strength at 0.10 mol dm⁻³ by potentiometry. The constants of the systems were calculated by using BEST computer program, and distribution species diagrams were produced using the SPE computer program. The protonation constants were influenced by changes in solvent composition, and their variations were discussed in terms of solvent and structural properties. The concentration distribution of the various species in ethanol-water mixtures was evaluated.
ISSN:0939-4451
1438-2199
DOI:10.1007/s00726-008-0054-5