Harris PWR, Brimble MA. A comparison of Boc and Fmoc SPPS strategies for the preparation of C-terminal peptide α-thiolesters: NY-ESO-1 ³⁹Cys-⁶⁸Ala-COSR.
Biopolymers 2016;
100:356-65. [PMID:
23444272 DOI:
10.1002/bip.22223]
[Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/06/2013] [Accepted: 02/11/2013] [Indexed: 01/08/2023]
Abstract
The synthesis of a polypeptide derived from the cancer testis antigen NY-ESO-1 bearing a C-terminal α-thiolester is described. Employing tert-butyloxycarbonyl solid phase peptide synthesis the thiolester moiety was installed on-resin using a mercaptopropionic acid linker, thereby requiring no post synthetic manipulations and delivering the requisite α-thiolester polypeptide after cleavage from the resin with HF. Several 9-fluorenylmethyloxycarbonyl solid phase peptide synthesis approaches whereby the thiolester was required to be introduced in a post synthesis manner were examined concurrently. These comprised syntheses on two different "safety catch" linkers, an N-alkyl-N-acyl sulphonamide and an N-acyl benzimidazolone wherein the thiolester is generated from an activated precursor. The condensation of a mercaptan with the C-terminal carboxylate in a direct thiolesterification reaction was also examined. When using either of the three 9-fluorenylmethyloxycarbonyl-based approaches, the linear polypeptide could be assembled straightforwardly on the solid phase resin; however, a thiolesterification of the C-terminal carboxyl of the fully side chain protected peptide proved to be the most effective post-assembly method for the installation of the C-terminal thiolester.
Collapse