Chemo-Enzymatic Synthesis of Fmoc-Peptide Fragments

Enzymatic Protecting Group Techniques

“…The N-terminal urethanes and the peptide linkages are left intact. A further protease which fulfills the requirements for a successful application in peptide chemistry is alcalase, a serine endopeptidase from Bacillus licheniformis whose major component is subtilisin A (Subtilisin Carlsberg). − It can advantageously be employed to selectively saponify peptide methyl and benzyl esters (Figure ). In a solvent system consisting of 90% tert -butyl alcohol and 10% buffer (pH 8.2), even highly hydrophobic and in aqueous solution insoluble Fmoc peptides were accepted as substrates and deprotected at the C-terminus without any disturbing side reaction.…”

Synthesis of Fmoc-Protected (S,S)-trans-Cyclopentane Diamine Monomers Enables the Preparation and Study of Conformationally Restricted Peptide Nucleic Acids

“…A methyl ester protecting group was selected with the idea that it could be potentially removed under mildly basic or enzymatic conditions with minimal impact to the base-sensitive Fmoc or the acid-sensitive Bhoc in the A, C, and G nucleobases. In the optimized synthesis, additional improvements to the original protocol were also developed (Scheme ).…”