The dual activity of pyruvate kinase type M 2 from chromatin extracts of neoplastic cells

Abstract

Pyruvate kinase type M 2 from Morris hepatoma 7777 tumour cell nuclei and cytosol, in contrast to types L and M 2 from nuclei and cytosol of normal rat liver, shows the histone H 1 kinase activity. Moreover, in the presence of l-cysteine and without ADP it converts 2-phosphoenolpyruvate (PEP) to pyruvate while in the presence of l-arginine or l-histidine does not. l-Cysteine markedly stimulates the activity of histone H 1 kinase transferring a phosphate group from PEP to, as results suggested, the ε-amino group of l-lysine of histone H 1. This, l-cysteine which is known to inhibit the activity of pyruvate kinase type M 2 from neoplastic cells transfering a phosphate from PEP to ADP, can act as a control factor champing the direction of enzymatic reaction in cancer cells.