Potentiometric alkali titration data for the full tripeptide set composed from the combination of Glutamic acid (Glu, E), Glycine (Gly, G) and Histidine (His, H), measured between pH 3-12

Abstract

Peptides were purchased from Genosphere, Sigma Aldrich and Bachem companies. All the peptides were chemically synthesised. Aldrich and Bachem supplied the peptides as their Zwitterionic form, Genosphere synthesised the peptides as tri-fluoro acetic salt TFA salts. The peptides were of purity higher than 98% and were used without any further purification.All peptides solutions were prepared at 0.001M concentration in milliQ water, Hydrochloric acid HCl 0.002M in order to have relatively the same initial pH of 2.6 valueThe potentiometric titrations were recorded at 25°C in 10ml conical flask under Nitrogen atmosphere. NaCLO4 sodium perchlorate was used as ino background at 0.1M to maintain relatively a consistent ionic strength during titration. Standardised NaOH 0.1M was the titrant, and it was added as 5µM increment until pH reaches 11.