Résumé
Protease mediated bond synthesis, first reported by Bergmann and Fraenkel-Conrat [1], has received increasing interest due to the inherent advantages it possesses over chemically-based peptide bond syntheses. A Glu/Asp specific endoprotease, very recently isolated from Bacillus licheniformis[2], belonging to the serin group and called BL-GSE, is able to catalyse the coupling of a lot of different nucleophiles (H-Xxx-NH2) corresponding to P1' position (Schechter and Berger notation) on Glu or Asp residues under kinetic control [3]. The effect of water miscible organic solvents (DMF,Methanol or acetonitrile) has been studied in an attempt to diminish esterase activity and secondary reverse hydrolysis of the new peptide bond.