Functions of nucleotide binding subunits in the tonoplast ATPase from Beta vulgaris L

Conference · Tue Apr 01 04:00:00 EST 1986 · Plant Physiol.; (United States)

OSTI ID:5433650

Manolson, M F; Poole, R J

Partial purification of NO/sub 3/ sensitive H/sup +/-ATPases from the vacuolar membranes of high plants reveal two prominent polypeptides of approximately 60 and 70 kDa. Both polypeptides appear to contain nucleotide binding sites. The photoactive affinity analog of ATP, BzATP, cannot be hydrolyzed by the tonoplast ATPase but is a potential inhibitor (apparent K/sub I/ = 11 ..mu..M). /sup 32/P-BzATP was shown to specifically photolabel the 60 kDa polypeptide. In contrast, Mandala and Taiz have shown the photoincorporation of /sup 32/P-azidoATP to the 70 kDa polypeptide. This sterically different photoaffinity probe can be hydrolyzed although with a low affinity. Azido and benzophenone derivatives of the product, ADP, are currently being examined with respect to their inhibition kinetics of, and their photoincorporation into, the tonoplast ATPase from Beta vulgaris L. Kinetic data will be integrated with patterns of photoincorporation using analogs of both substrate and product, in order to illuminate the functions of the two nucleotide binding subunits.

• Research Organization: McGill Univ., Montreal, Quebec
• OSTI ID: 5433650
• Conference Information: Journal Name: Plant Physiol.; (United States) Journal Volume: 80:4
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ADP
ATP-ASE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
DAYS LIVING RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
FUNCTIONS
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHOHYDROLASES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PLANTS
PROTEIN STRUCTURE
RADIOISOTOPES
REACTION KINETICS
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES