Inactivation of the brain Na+,K+-ATPase catalytic subunit isoforms by sodium dodecyl sulfate

The comparative study of the stabilities to SDS inactivation of the brain and kidney Na+,K+-ATPase isozymes under different time and temperature conditions of the microsome extraction with the detergent was conducted. In contrast to the enzyme preparations from medulla oblongata the higher sensitivity of the Na+,K+-ATPase alpha-isoform (in comparison to alpha(+)) to SDS inactivation accompanied by its, at least, partial removal from the membrane was found in the preparations from cerebral cortex, This difference in the sensitivity to SDS are eliminated after extraction of microsomes with the detergent at 37 degrees C. The results interpretation is based on the assumption on the existence of differences in structural organization of the boundary lipids of the neuronal Na+,K+-ATPase catalytic subunit isoforms.