Solid phase synthesis of peptides and proteins

Abstract

A strategy for the total chemical synthesis and purification of proteins has been investigated and applied to the 85 residue methylated DNA binding domain (MBD) from the chromosomal protein MeCP2, the 66 residue Restriction Alleviation (Ral) protein from bacteriophage λ, and the 76 residue ß-chemokine Monocyte Chemotactic protein (MCP-1). The hydrophobicity of the Nᵃ protecting group tetrabenzo[a, c ,g, i]fluorenyl- 17- methoxycarbonyl (Tbfmoc) has been exploited to simplify the rapid purification of the 85 amino acid MBD protein by Hplc. Initial structural studies on the synthetic protein are also reported. In addition a comparative study of semi -permanent, temporary and enzyme cleavable thiol protection has resulted in the extension of this Tbfmoc methodology to the synthesis of cysteine containing proteins such as Ral and MCP -1.A general route to C- terminal α- hydroxyglycine extended peptides via Fmoc/t-Bu based solid phase peptide synthesis is also described. Such peptides are the biosynthetic precursors of peptide amides in which the C-terminal carboxamide functionality is required for biological activity in a number of important hormones.