Identification of a third form of NaK-ATPase catalytic subunit in rat brain by photoaffinity labeling
Using photoaffinity labeling, they have found a form of the NaK-ATPase catalytic subunit, ..cap alpha..(-), in the rat brain that is distinct from the ..cap alpha.. and ..cap alpha..(+) forms. Strong radiolabeling of ..cap alpha..(-) was obtained with (/sup 125/I)azido-iodophenethylamido-succinyl-cymarin (AISC). AISC is a new cardiotonic steroid photolabel which they have synthesized and characterized chemically and biochemically. This compound labels ..cap alpha..(-) better than the photolabels that they have previously reported. SDS-PAGE (5%) of photolabeled rat brain microsomes showed that ..cap alpha..(-) migrated with faster mobility than the dog kidney ..cap alpha.. subunit. The ..cap alpha..(-) appears to have different specificity for different cardiotonic steroids than either ..cap alpha..(+) or ..cap alpha... The radiolabeling of rat brain ..cap alpha..(+) and dog kidney ..cap alpha.. with (/sup 125/I)AISC was protectable by ouabain; in contrast, 1 mM ouabain did not reduce the (/sup 125/I)AISC-labeling of ..cap alpha..(-), although the labeling was protected with 200 ..mu..M cymarin or AISC. The results indicate that the ..cap alpha..(-) form of the NaK-ATPase in rat brain binds cymarin and its derivative but has little affinity for ouabain. It is possible that ..cap alpha..(-) may be the translation product of the rat brain ..cap alpha..(III) mRNA which has recently been described.
- Research Organization:
- Univ. of Wisconsin, Madison
- OSTI ID:
- 6173395
- Report Number(s):
- CONF-870644-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ATP-ASE
BIOCHEMICAL REACTION KINETICS
LABELLING
AFFINITY
BRAIN
ELECTROPHORESIS
IODINE 125
MICROSOMES
RATS
SPECIFICITY
STEROIDS
TRACER TECHNIQUES
ACID ANHYDRASES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PHOSPHOHYDROLASES
RADIOISOTOPES
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques