Inactivation of gamma-aminobutyric acid aminotransferase by (S,E)-4-amino-5-fluoropent-2-enoic acid and effect on the enzyme of (E)-3-(1-aminocyclopropyl)-2-propenoic acid.

Published

Journal Article

(S,E)-4-Amino-5-fluoropent-2-enoic acid (6) is synthesized in six steps starting from the known gamma-aminobutyric acid aminotransferase (gamma-Abu-T) inactivator, (S)-4-amino-5-fluoropentanoic acid (1). Compound 6 is a mechanism-based inactivator of gamma-Abu-T: time-dependent inactivation is saturatable and protected by substrate; thiols do not protect the enzyme from inactivation; no enzyme activity returns upon dialysis. This compound (6) binds 50 times more tightly to gamma-Abu-T than does the saturated analogue (1). No transamination of 6 occurs prior to inactivation. However, five molecules of 6 are required to inactivate the enzyme with concomitant release of five fluoride ions. Therefore, four molecules are being converted to product for each inactivation event. (E)-3-(1-Aminocyclopropyl)-2-propenoic acid is synthesized in seven steps from 1-aminocyclopropanecarboxylic acid. It is prepared as a cyclopropyl derivative of the proposed intermediate in the inactivation of gamma-Abu-T by 6. The cyclopropyl derivative, however, is a noncompetitive inhibitor and does not inactivate the enzyme. This study shows the usefulness and hazards of incorporation of a trans double bond into potential gamma-Abu-T inactivators.

Full Text

Cited Authors

  • Silverman, RB; Invergo, BJ; Mathew, J

Published Date

  • October 1, 1986

Published In

Volume / Issue

  • 29 / 10

Start / End Page

  • 1840 - 1846

PubMed ID

  • 3761305

Pubmed Central ID

  • 3761305

Electronic International Standard Serial Number (EISSN)

  • 1520-4804

International Standard Serial Number (ISSN)

  • 0022-2623

Digital Object Identifier (DOI)

  • 10.1021/jm00160a007

Language

  • eng