# name
Understanding acid lability on Cysteine protecting groups

# metadata.dc.description.abstract[].value
Cys-disulfide bonds contribute to the stabilization of peptide and protein structures. The synthesis of these molecules requires a proper protection of Cys residues, which is crucial to prevent side-reactions and also to achieve the correct Cys connectivity. Here we undertook a mechanistic study of a set of well-known acid-labile Cys protecting groups, as well other new promising groups, in order to better understand the nature of their acid-lability. The stability of the carbocation generated during the acid treatment was found to have a direct impact on the removal of the protective groups from the corresponding protected Cys-containing peptides. Hence a combination of steric and conjugative effects determines the stability of the carbocations generated. Here we propose diphenylmethyl (Dpm) as a promising protecting group on the basis of its intermediate relative carbocation stability. All the optimized geometries and energies presented in this study were determined using a B3LYP/6-31G(d,p) calculation. The results discussed herein may be of broader applicability for the development of new protecting groups.

# metadata.dc.rights[].value
cc-by (c) Ramos Tomillero, Iván et al., 2013

# metadata.dc.source[].value
Articles publicats en revistes (Química Inorgànica i Orgànica)

# metadata.dc.title[].value
Understanding acid lability on Cysteine protecting groups