Effect of water-miscible aprotic solvents on kyotorphin synthesis catalyzed by immobilized α-chymotrypsin

✍ Scribed by Pedro Lozano; Teresa Diego; José L. Iborra

• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 353 KB
• Volume: 17
• Category: Article
• ISSN: 0141-5492
• DOI: 10.1007/bf00129386

✦ Synopsis

Immobilized a-chymotrypsin was used as catalyst to synthesize a kyotorphin derivative (Bz-Tyr-Arg-OEt) in the presence of five water-miscible aprotic solvents (dimethylsulphoxide, dimethylformamide, acetonitrile, acetone and tetrahydrofurane) at 30 °C. By using a kineticallycontrolled approach, the maximum synthetic activity was obtained when Arg-OEt was used as nucleophile donor at a concentration 1.5-times higher than the acyl-acceptor substrate (Bz-Tyr-OEt). The water-miscible aprotic solvents enhanced greatly the synthetic activity proportionally to their hidrophilicity properties adequately measured by the log P parameter. At the optimum solvent concentration for the enzymatic peptide synthesis, both the water activity (Aw) of the media and the water content of the immobilized derivative showed a saturation profile against the log P parameter. As a function of the solvent hydrophilicity, these water parameters were shown as key parameters for the increase in the synthetic activity of the enzyme by the presence of these solvents.