Inhibition and labeling of the plant plasma membrane H/sup +/-ATPase with N-ethylmaleimide

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol.; (United States)

OSTI ID:6065766

Katz, D B; Sussman, M R

H/sup +/-ATPase activity in plasma membranes isolated from Avena sativa root cells is inhibited by N-ethylmaleimide, a covalent modifier of protein sulfhydryl groups. The rate of inhibition is reduced by ADP, MgADP, and MgATP, but even at 40 millimolar ADP the enzyme is only partially protected against inactivation. When plasma membranes are treated with N-(2-/sup 3/H)ethylmaleimide and analyzed by sodium dodecyl sulfate polyaerylamide gel electrophoresis, prominent radioactive bands appear at M/sub r/ = 100,000 and several other positions. However, only radioactivity in the M/sub r/ = 100,000 protein is reduced by the presence of MgADP. These results provide independent evidence that the M/sub r/ = 100,000 polypeptide which is observed in purified preparations of the enzyme is the catalytic subunit of the H/sup +/-ATPase. When tryptic peptides are produced from N-(2-/sup 3/H)ethylmaleimide labeled M/sub r/ = 100,000 protein and separated by reverse phase high performance liquid chromatography, two radioactive peaks are observed for which N-(2-/sup 3/H)ethylmaleimide incorporation is reduced in the presence of MgADP.

• Research Organization: Univ. of Wisconsin, Madison
• DOE Contract Number: AC02-83ER13086
• OSTI ID: 6065766
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 83:4; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ADP
ANTIMITOTIC DRUGS
ATP-ASE
CELL CONSTITUENTS
CELL MEMBRANES
CEREALS
CHARGED-PARTICLE TRANSPORT
CHROMATOGRAPHY
DRUGS
ELECTROPHORESIS
ENZYME INHIBITORS
ENZYMES
GRASS
HYDROLASES
IMIDES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MEMBRANES
NEM
NUCLEOTIDES
OATS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDES
PHOSPHOHYDROLASES
PLANTS
POLYPEPTIDES
PROTEINS
PROTON TRANSPORT
RADIATION TRANSPORT
RADIOSENSITIZERS
ROOTS
SEPARATION PROCESSES
TRACER TECHNIQUES
TRITIUM COMPOUNDS