Acetylglutamate synthase in Neurospora crassa: characterization, localization, and genetic behavior of a regulatory enzyme of arginine biosynthesis

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6080100

Jacobson, J A

This study describes the characterization and localization of the first enzyme of arginine biosynthesis in Neurospora crassa. A radioactive assay was developed to detect this enzyme whereby radioactive substrate and product molecules could be separated by ion-exchange chromatography. The enzyme was found to have a pH optimum of 9.0 and K/sub m/ values for glutamate and acetyl-CoA of approximately 4.7 and 0.45 mM, respectively. The enzyme was shown to be feedback inhibited by arginine. Half-maximal inhibition was observed at 0.13 mM arginine, a concentration which is similar to be in vivo cytosolic concentration of 0.2 mM. Arginine was found to act as a competitive inhibitor with respect to acetyl-CoA. Acetylglutamate synthase was localized to the mitochondrion. However, in contrast to the mitochondrial matrix location of the other ornithine biosynthetic enzymes, this enzyme was found to reside on the mitochondrial inner membrane.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 6080100
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ARGININE
BIOCHEMISTRY
BIOLOGICAL LOCALIZATION
BIOSYNTHESIS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL COMPOSITION
CHEMISTRY
CHROMATOGRAPHY
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
EUMYCOTA
FUNGI
ION EXCHANGE CHROMATOGRAPHY
LIGASES
MEMBRANES
MITOCHONDRIA
NEUROSPORA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANOIDS
PLANTS
RADIOASSAY
SEPARATION PROCESSES
SYNTHESIS