Fig. 1
From: Metabolic acidosis and 5-oxoprolinuria induced by flucloxacillin and acetaminophen: a case report
The γ-glutamyl cycle. Step 1: Glutathione synthetase deficiency induces a decrease in the levels of glutathione and an increase of γ - glutamyl cysteine. Step 2: Glutathione deficiency induces negative feedback in the γ-glutamyl-cysteine synthetase. Step 3: 5-oxoproline is produced by γ-glutamyl cyclotransferase from γ-glutamyl-cysteine. Step 4: 5-oxoproline is converted to L-glutamate by the 5-oxoprolinase, which is quickly saturated