You are examining the characteristics of erythrocytes from a patient who suffers from recurrent episodes of mild hemolytic anemia. Your analysis of these cells shows that they are highly sensitive to oxidative stress likely due to the fact that they contain significantly less glutathione than normal erythrocytes. A deficiency in which of the following enzymes is likely in these erythrocytes?

Question

Quizplus · Accepted Answer

γ-Glutamylcysteine synthetase is the enzyme responsible for the first step in glutathione synthesis. A deficiency in this enzyme would lead to reduced glutathione levels, making erythrocytes more susceptible to oxidative stress.  Glutathione (GSH) is synthesized in the cytosol of all mammalian cells. The rate of GSH synthesis is dependent upon the availability of cysteine and the activity of the rate-limiting enzyme, g-glutamylcysteine synthetase (GCS).

You Are Examining the Characteristics of Erythrocytes from a Patient