The role of the carboxylate ion in models of acyl-chymotrypsin

✍ Scribed by Weida Tong; Valerian T. D'Souza

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 810 KB
• Volume: 16
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540160606

✦ Synopsis

Abstract

Two exquisite models of the acyl‐chymotrypsin intermediate, one designed by Bruice and another by Bender, were studied to elucidate the role of the carboxylate ion in the catalytic triad of serine proteases. However, opposing conclusions were drawn from these studies. Computational chemistry analysis of these models indicates that the carboxylate ion plays an insignificant role in the former model because of the correct orientation and the distance of the imidazole group without the carboxylate ion. However, in the latter model, the carboxylate ion serves to orient and place the imidazole group at the correct position. This analysis suggests that an important role of the carboxylate ion in serine proteases is to position the imidazole group to be an effective general base catalyst. © 1995 by John Wiley & Sons, Inc.