Mechanism of inactivation of. gamma. -aminobutyrate aminotransferase by 4-amino-5-fluoropentanoic acid. First examples of an enamine mechanisms for a. gamma. -amino acid with a partition ratio of 0

Journal Article · Tue Nov 04 00:00:00 EST 1986 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00370a013· OSTI ID:6550809

Silverman, R B; Invergo, B J

The mechanism of inactivation of pig brain ..gamma..-aminobutyric acid aminotransferase (GABA-T) by (S)-4-amino-5-fluoropentanoic acid (1, R = CH/sub 2/CH/sub 2/COOH, X = F) previously proposed is revised. apo-GABA-T is reconstituted with (4-/sup 3/H)pyridoxal 5'-phosphate and inactivated with 1 (R = CH/sub 2/CH/sub 2/COOH, X = F). Treatment of inactivated enzyme with base followed by acid denaturation leads to the complete release of radioactivity as 6-(2-hydroxy-3-methyl-6-(phosphonoxymethyl)-4-pyridinyl)-4-oxo-5-hexenoic acid (4, R = CH/sub 2/CH/sub 2/COOH). Alkaline phosphatase treatment of this compound produces dephosphorylated 4 (R = CH/sub 2/CH/sub 2/COOH). These results support a mechanism that was suggested by Metzler and co-workers for the inactivation of glutamate decarboxylase by serine O-sulfate (Scheme I, pathway b, R = COOH, X - OSO/sub 3//sup -/).

• Research Organization: Northwestern Univ., Evanston, IL
• OSTI ID: 6550809
• Journal Information: Biochemistry; (United States), Vol. 25:22
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AMINOTRANSFERASES
BIOCHEMISTRY
INACTIVATION
TRITIUM COMPOUNDS
AMINO ACIDS
BIOLOGICAL PATHWAYS
BRAIN
ENZYME ACTIVITY
MONOCARBOXYLIC ACIDS
SCINTILLATION COUNTING
SWINE
VALERIC ACID
ANIMALS
BODY
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CHEMISTRY
COUNTING TECHNIQUES
DOMESTIC ANIMALS
ENZYMES
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
NITROGEN TRANSFERASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
TRANSFERASES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques