Convergent solid phase peptide synthesis - III. Synthesis of the 44-52 protected segment of the toxin II of Androctonus australis Hector

Article abstract of DOI:10.1016/S0040-4020(01)87472-X

The synthesis of the fully protected peptide Boc-Asn-Ala-Cys(Acm)-Tyr(cHex)-Cys(Acm)-Tyr(cHex)-Lys(Z)-Leu-Pro- OH which corresponds to the 44-52 sequence of the Androctonus australis Hector toxin II is described. The synthesis has been carried out on a bromomethyl-Nbb-resin which provides a photolabile anchorage of the peptide. The experimental conditions of the photolysis reaction are very critical in order to obtain satisfactory cleavage yields. The influence of the solvent in this reaction is discussed taking into account the swelling properties of different solvent mixtures and the formation of coloured side-reaction products. Finally, dimethylformamide/water precipitation followed by reverse phase HPLC is shown to be a very convenient approach to the purification of fully protected peptides.