title: Measurement and modeling of acid dissociation constants of tri-peptides containing Glu, Gly, and His using potentiometry and generalized multiplicative analysis of variance.
abstract: We report pK(a) values with measurement uncertainties for all labile protons of the 27 tri-peptides prepared from the amino acids glutamic acid (E), glycine (G) and histidine (H). Each tri-peptide (GGG, GGE, GGH, …, HHH) was subjected to alkali titration and pK(a) values were calculated from triplicate potentiometric titrations data using HyperQuad 2008 software. A generalized multiplicative analysis of variance (GEMANOVA) of pK(a) values for the most acidic proton gave the optimum model having two terms, an interaction between the end amino acids plus an isolated main effect of the central amino acid.
authors.affiliation: School of Chemistry, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Rima Raffoul
authors.initials: RR
authors.lastname: Khoury
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Sutton
authors.forename: D Brynn
authors.initials: DB
authors.lastname: Hibbert
authors.forename: Diako
authors.initials: D
authors.lastname: Ebrahimi
mesh_terms: D018698:Glutamic Acid / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D011199:Potentiometry; D012984:Software
chemical_list: D009842:Oligopeptides; D018698:Glutamic Acid; D006639:Histidine; D005998:Glycine