Solid-Phase Synthesis of an "Inaccessible" hGH-Derived Peptide Using a Pseudoproline Monomer and SIT-Protection for Cysteine.

The solid-phase peptide synthesis (SPPS) of the C-terminal sequence of hGH with one extra Tyr attached to its N-terminus (total of 16 residues with a disulfide bridge) has been accomplished for the first time by optimizing several synthetic parameters. First of all, the two Ser residues (positions 9 and 13 of the molecule) have been introduced as a single amino acid, Fmoc-Ser(ψpro)-OH, demonstrating that the acylation of these hindered moieties is possible. This allows us to avoid the use of the corresponding dipeptides, Fmoc-AA-Ser(ψpro)-OH, which are very often not commercially available or very costly.

Solid-Phase Peptide Synthesis Using a Four-Dimensional (Safety-Catch) Protecting Group Scheme.

Peptides of importance to both academia and industry are mostly synthesized in the solid-phase mode using a two-dimensional scheme. The so-called Fmoc/Bu strategy, where the groups are removed by piperidine and TFA, respectively, is currently the method of choice for peptide synthesis. However, as the molecular diversity of cyclic and branched peptides becomes a challenging interest, a high level of orthogonal dimensionality is required, such as through triorthogonal protection schemes.

Eco-friendly combination of the immobilized PGA enzyme and the S-Phacm protecting group for the synthesis of Cys-containing peptides.

Enzyme-labile protecting groups have emerged as a green alternative to conventional protecting groups. These groups introduce a further orthogonal dimension and eco-friendliness into protection schemes for the synthesis of complex polyfunctional organic molecules. S-Phacm, a Cys-protecting group, can be easily removed by the action of a covalently immobilized PGA enzyme under very mild conditions.

N-Fmoc-α-sulfo-β-alanine: a versatile building block for the water solubilisation of chromophores and fluorophores by solid-phase strategy.

An easy and efficient solid-phase synthesis strategy to obtain rapidly water-soluble chromophores/fluorophores in highly pure form has been developed. This first successful use of N-Fmoc-α-sulfo-β-alanine as a SPPS building block opens the way to the future development of promising direct "on-resin" peptide labelling and water-solubilising methods.

From production of peptides in milligram amounts for research to multi-tons quantities for drugs of the future.

Peptides are key to modern drug discovery. This article reviews the requirements for bulk production of peptides and how it affects research and production of smaller scales. Peptides, as modern drugs, are currently produced in millions in mg-scale for research purpose, in order to better understand the function of biological systems.