Protease-catalyzed peptide synthesis using inverse substrates: The synthesis of Pro-Xaa-bonds by trypsin

✍ Scribed by Volker Schellenberger; Ute Schellenberger; Hans-Dieter Jakubke; Nina P. Zapevalova; Yuri V. Mitin

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 296 KB
• Volume: 38
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260380314

✦ Synopsis

Benzyloxycarbonyl-L-proline p-guanidinophenyl ester is an "inverse substrate" for trypsin; i.e., the cationic center is included in the leaving group instead of being in the acyl moiety. This substrate can be used in trypsin-catalyzed acyl-transfer reactions leading to the sythesis of Pro-Xaa peptide bonds. The reaction proceeds about 20 times slower than reactions with similar alanine-containing substrates, but the ratio between synthesis and hydrolysis is more favorable. The investigation of a series of nucleophiles led to information about the specificity of the process. Nucleophiles differing only in the P;-position show an increasing acyl transfer efficiency in the order Phe < Gly < Ley < Ser < Ala < Ile. C terminal elongation of the nucleophiles is of minor influence on their efficiency. The formation of an H bond between the acyl-enzyme and the nucleophile Seems to play an important role in the aminolysis of the acyl-enzyme.