Understanding acid lability on Cysteine protecting groups

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...

Descripción completa

Detalles Bibliográficos
Autores: Ramos Tomillero, Iván, Mendive Tapia, Lorena, Góngora Benítez, Miriam, Nicolás Galindo, Ernesto, Tulla-Puche, Judit, Albericio Palomera, Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/152584
Acceso en línea:https://hdl.handle.net/2445/152584
Access Level:acceso abierto
Palabra clave:Síntesi de pèptids
Proteïnes
Cisteïna
Catàlisi
Peptide synthesis
Proteins
Cysteine
Catalysis
Descripción
Sumario: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.