several lines of evidence are presented that an entity is present in mitochondria which converts lysine and carbamylphosphate to homocitrulline , distinct from the ornithine transcarbamylase ( otc ) : lack of inhibition by lysine of otc with ornithine as substrate at the ph of the mitochondrial matrix , a km for lysine of 6.3 mmol/l in the crude mitochondrial extract , versus a km of 55.3 mmol/l after partial purification of otc , decrease of the specific activity of otc with lysine as substrate and increase of the specific activity with ornithine as substrate after heat denaturation , and separation of the activities for ornithine and lysine after isoelectric focusing .
C1510421
mitochondrial matrix
C0026237
mitochondrial