Solid-Phase Synthesis of C-Terminus Cysteine Peptide Acids

Cysteine (Cys) is a key amino acid in many therapeutic peptides. For research and industrial purposes, solid-phase peptide synthesis is the method of choice for the preparation of most peptides. The solid-phase synthesis of C-terminal Cys peptide acids is problematic because it is accompanied by a s...

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Detalles Bibliográficos
Autores: Mthembu, Sinenhlanhla N., Chakraborty, Amit, Schönleber, Ralph, Albericio, Fernando, De La Torre, Beatriz G.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/284404
Acceso en línea:http://hdl.handle.net/10261/284404
https://api.elsevier.com/content/abstract/scopus_id/85142147897
Access Level:acceso abierto
Palabra clave:Solid-phase peptide synthesis
4-methylpiperidine
Epimerization
Racemization
Side reaction
Descripción
Sumario:Cysteine (Cys) is a key amino acid in many therapeutic peptides. For research and industrial purposes, solid-phase peptide synthesis is the method of choice for the preparation of most peptides. The solid-phase synthesis of C-terminal Cys peptide acids is problematic because it is accompanied by a side reaction, namely, the abstraction of α-H from the Cys residue, which leads to the formation of three side products: the epimer and two N-piperidinyl-Ala epimer peptides. Here, we used a chlorotrityl chloride resin to conduct a rational and in-depth study of this side reaction. The following variables were examined: removal of the fluorenylmethoxycarbonyl (Fmoc) group by different bases, the presence or absence of an acid rectifier for buffering the base, and thiol side-chain protection. In conclusion, the use of Fmoc-Cys protected with tetrahydropyran (Thp) and 4-methoxytrityl (Mmt) along with 30% 4-methylpiperidine in 0.5 M OxymaPure-DMF for Fmoc removal assures minimization of the side reaction, as demonstrated in a model peptide and confirmed for the elongation of somatostatin.