Convergent solid phase peptide synthesis. v. synthesis of the 1-4, 32-34, and 53-59 protected segments of the toxin ii of androctonus australis hector.

Two protected peptide segments corresponding to the sequence 32-34 and 53-59 of toxin II of the north African scorpion Androctonus australis Hector have been synthesized on a photolabile Nbb-resin using the TFA-labile Boc -amino protection and HF-labile side chain protecting groups. A third protected peptide corresponding to segment 1-4 has been synthesized on the same resin but with a t-butyl group for β protection of aspartic acid and a Z group on the lysine side chain. For this last segment a combination of Boc and Fmoc groups for -amino protection has been used successfully on the Nbb-resin. After photolysis the crude peptides have been treated by solvent extraction and semi-preparative HPLC to yield highly purified segments. These syntheses show the flexibility of the convergent solid phase approach and how segments with different and independent protecting groups can be assembled by solid phase peptide procedure.