Identification of an AMP-activatable pyruvate dehydrogenase isozyme in embryos and tumors

Abstract

We have found that the pyruvate dehydrogenase of ascites tumor cells is activated by AMP in what appears to be an allosteric effect not detected in any of several normal tissues examined. We report now that this activation of a pyruvate dehydrogenase by AMP applies also to the enzyme in a human embryo, chicken embryos and a human tumour. These observations suggest that there is a fetal isozyme of pyruvate dehydrogenase, or at least of its decarboxylase component, that tends to appear in tumours. To our knowledge no information has been published on the occurrence of isozymes of pyruvate dehydrogenase.