In situ assembly states of (Na+,K+)-pump ATPase in human erythrocytes. Radiation target size analyses

Journal Article · Fri Nov 15 04:00:00 EST 1985 · J. Biol. Chem.; (United States)

OSTI ID:6332566

Hah, J; Goldinger, J M; Jung, C Y

The in situ assembly state of the (Na+,K+)-pump ATPase of human erythrocytes was studied by applying the classical target theory to radiation inactivation data of the ouabain-sensitive sodium efflux and ATP hydrolysis. Erythrocytes and their extensively washed white ghosts were irradiated at -45 to -50 degrees C with an increasing dose of 1.5-MeV electron beam, and after thawing, the Na+-pump flux and/or enzyme activities were assayed. Each activity measured was reduced as a simple exponential function of radiation dose, from which a radiation sensitive mass (target size) was calculated. When intact cells were used, the target sizes for the pump and for the ATPase activities were equal and approximately 620,000 daltons. The target size for the ATPase activity was reduced to approximately 320,000 daltons if the cells were pretreated with digitoxigenin. When ghosts were used, the target size for the ATPase activity was again approximately 320,000 daltons. Our target size measurements together with other information available in literature suggest that (Na+,K+)-pump ATPase may exist in human erythrocytes either as a tetramer of alpha beta or as a dimer of alpha beta in tight association with other protein mass, probably certain glycolytic enzymes, and that this tetrameric or heterocomplex association is dissociable by digitoxigenin treatment or by extensive wash during ghost preparation.

• Research Organization: Veterans Administration Medical Center, Buffalo, NY
• OSTI ID: 6332566
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 26; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID ANHYDRASES
ALKALI METAL COMPOUNDS
ALKALI METALS
ATP
ATP-ASE
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
DECOMPOSITION
DOSES
DRUGS
ELEMENTS
ENZYME ACTIVITY
ENZYMES
ERYTHROCYTES
GLYCOSIDES
HYDROLASES
HYDROLYSIS
IONS
IRRADIATION
LYSIS
MATERIALS
MEMBRANE TRANSPORT
METALS
MOLECULAR WEIGHT
NUCLEOTIDES
ORGANIC COMPOUNDS
OUABAIN
PHOSPHOHYDROLASES
POTASSIUM COMPOUNDS
RADIATION DOSES
SODIUM
SODIUM COMPOUNDS
SOLVOLYSIS
STROPHANTHINS