DISTRIBUTION OF SOLUBLE AND MEMBRANE-BOUND FORMS OF GLUTAMINASE IN PIG BRAIN

Abstract— About 10% of the glutaminase activity associated with pig brain mitochondria was readily extractable by a variety of techniques but the remainder was very resistant to extraction. These two forms, which have been termed the soluble and membrane‐bound forms respectively, have been shown to differ in their responses to activation by phosphate and phosphate‐borate containing buffers. Submitochondrial fractionation studies indicated that the soluble form was located in the mitochondrial inner matrix whereas the membrane‐bound form was associated with the inner membrane. The mitochondria associated with the synaptosomes were found to contain only the membrane‐bound form of the enzyme whereas both forms were present in the free brain mitochondria. Copyright © 1979, Wiley Blackwell. All rights reserved