Low-Barrier Hydrogen Bond in the Catalytic Triad of Serine Enzymes

  • Rohit Medhekar
  • Nathan Baker
  • Kenneth Sando
  • William Kearney
  • Daniel Quinn

Abstract

Acetylcholinesterase (AChE) and chymotrypsin are serine enzymes whose catalytic mechanism involves a nucleophilic attack (serine) and a general acid-base moiety (histidine). The incipient imidiazolium which is formed as a result of the nucleophilic attack by serine is stabilized by the negatively charged carboxylate (Glu or Asp). This transition state stabilization is thought to be gained by a low-barrier hydrogen bond (LBHB) in which the proton is centrally located between N5 and the carboxylate oxygen.

Keywords

Carboxylate Serine Histidine Triad Cholinesterase 

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • Rohit Medhekar
    • 1
  • Nathan Baker
    • 2
  • Kenneth Sando
    • 1
  • William Kearney
    • 1
  • Daniel Quinn
    • 1
  1. 1.Department of ChemistryThe University of IowaIowa CityUSA
  2. 2.Department of PharmacologyUniversity of California at San DiegoLa JollaUSA

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