Effect of tungsten and vanadium on the in vitro assembly of assimilatory nitrate reductase utilizing Neurospora mutant nit-1

Journal Article · Sat Jun 01 04:00:00 EDT 1974 · J. Biol. Chem.; (United States)

OSTI ID:5195771

Lee, K Y; Erickson, R; Pan, S S; Jones, G; May, F; Nason, A

Tungsten or vanadium in a nutrient medium containing nitrate, but not ammonia, as the sole nitrogen source inhibited the formation of assimilatory NADPH-nitrate reductase (but not nitrate-inducible NADPH-cytochrome c reductase) and growth of wild type Neurospora crassa. Inhibition was prevented by high levels of molybdate in the nutrient medium but was not reversed by adding molybdate to subsequently prepared cell-free enzyme preparations. Neither tungsten nor vanadium was inhibitory when added to partially purified wild type Neurospora NADPH-nitrate reductase. Cell-free preparations of uninduced wild type grown in increasing concentrations of tungsten or vanadium showed progressive inhibition of ability to assemble nitrate reductase in vitro (with extracts of nitrate-induced Neurospora mutant nit-1) which was partially or entirely restored by subsequent addition of molybdate to the extracts of the tungsten- or vanadium-grown uninduced wild type. Tungsten or vanadium added to acid-treated bovine milk xanthine oxidase or to extracts of uninduced wild type also inhibited in vitro enzyme assembly, with added molybdate partially preventing inhibition. The tungsten or vanadium analogue of nitrate reductase formed in vivo or by in vitro assembly is considerably more labile than its molybdenum counterpart as indicated by the complete loss of /sup 185/W or /sup 48/V from the enzyme as a result of trichloroacetic acid precipitation or heat treatment.

• Research Organization: Johns Hopkins Univ., Baltimore, MD
• OSTI ID: 5195771
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 249:12; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
COENZYMES
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENZYME ACTIVITY
ENZYMES
EVEN-ODD NUCLEI
FUNGI
GROWTH
HEAVY NUCLEI
IN VITRO
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
METABOLISM
METALS
MINUTES LIVING RADIOISOTOPES
MOLYBDENUM
MUTANTS
NADP
NEUROSPORA
NITRATES
NITROGEN COMPOUNDS
NUCLEI
NUCLEOTIDES
NUTRIENTS
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PLANTS
RADIOISOTOPES
RESPONSE MODIFYING FACTORS
TRANSITION ELEMENTS
TUNGSTEN
TUNGSTEN 185
TUNGSTEN ISOTOPES
VANADIUM
VANADIUM 48
VANADIUM ISOTOPES