Large variations in acidity of terminal amide bonds in histamine-containing peptides as measured by proton DNMR

Abstract : The main objective of these studies is to quantitatively estimate pK variations of individual amide bonds as a function of the ionization state of end groups in peptides, determined on measuring macro- and micro- (if any) ionization constants. H-1 NMR spectra of aqueous solutions of eight model substrates were consequently recorded using a water suppression sequence, within large pH ranges. A set of programs was devised to treat NMR data over the entirety of pH-dependent NMR patterns, in order to smooth out errors arising in handling individual spectra. Rates of amide proton abstraction by hydroxide ions were obtained from the coalescence of methylene coupled protons and the decrease of NH bond signal intensities, allowing us to estimate and discuss peptide pKs on assuming back reprotonation at a diffusion-limited rate. Cis-trans isomerization rates in two substrates bearing a tert-Butyloxycarbonyl terminal group were put in parallel with the acidity of carbamic protons.
Type de document :
Article dans une revue
Tetrahedron, Elsevier, 2014, 70 (37), pp.6482-6496. 〈10.1016/j.tet.2014.07.024〉
Domaine :
Liste complète des métadonnées

https://hal.univ-lorraine.fr/hal-01494410
Contributeur : Srsmc Ul <>
Soumis le : jeudi 23 mars 2017 - 14:04:11
Dernière modification le : mardi 16 janvier 2018 - 10:24:44

Identifiants

Collections

Citation

Jean-Jacques Delpuech, Delphine Champmartin, Katalin Selmeczi, Bernard Henry. Large variations in acidity of terminal amide bonds in histamine-containing peptides as measured by proton DNMR. Tetrahedron, Elsevier, 2014, 70 (37), pp.6482-6496. 〈10.1016/j.tet.2014.07.024〉. 〈hal-01494410〉

Partager

Métriques

Consultations de la notice

42