/sup 3/H-DFMA metabolism in tobacco: non-specific, arginase mediated inhibition of ornithine decarboxylase activity

Conference · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:6072900

Slocum, R D; Feirer, R L

..cap alpha..-Difluoromethylarginine (DFMA) is a specific, enzyme-activated, irreversible inhibit of arginine decarboxylase (ADC) in vitro. ADC catalyzes the first step leading to putrescine biosynthesis and the activity of this enzyme is closely linked to overall polyamine (PA) biosynthesis in non-meristematic plant tissues. Consequently, ADC represents an important target enzyme for inhibitors of PA metabolism. DFMA has been shown to inhibit ADC activity in a variety of tissues in vivo but its specificity in tobacco was questioned since ornithine decarboxylase (ODC) activity was also inhibited. Further studies have shown that (/sup 3/H)-DFMA is efficiently hydrolyzed in tobacco to (/sup 3/H)-difluoromethylornithine (DFMO), an irreversible inhibitor of ODC. Tobacco and bovine arginases also catalyze the hydrolysis of DFMA in vitro, suggesting a role for this enzyme in mediating the non-specific inhibition of ODC by DFMA in tobacco flowers.

• Research Organization: Williams College, Williamstown, MA
• OSTI ID: 6072900
• Report Number(s): CONF-8707108-
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 83:4
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ARGININE
BIOSYNTHESIS
BODY
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLIC ACIDS
DECARBOXYLASES
ENZYME INHIBITORS
ENZYMES
FLOWERS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYASES
METABOLISM
NICOTIANA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORNITHINE
PLANT TISSUES
PLANTS
SYNTHESIS
TISSUES
TRACER TECHNIQUES
TRITIUM COMPOUNDS