Amino Acids that form Oxaloacetate

Asparagine is hydrolyzed by asparaginase, liberating ammonia and aspartate (Fig. 1). Aspartate loses its amino group by transamination to form oxaloacetate (see Fig. 1). [Note: Some rapidly dividing leukemic cells are unable to synthesize sufficient asparagine to support their growth.

This makes asparagine an essential amino acid for these cells, which,  therefore, require asparagine from the blood. Asparaginase, which hydrolyzes asparagine to aspartate, can be administered systemically to treat leukemia. Asparaginase lowers the level of asparagine in the plasma, thereby depriving cancer cells of a required nutrient.]

Figure 1: Metabolism of asparagine and aspartate. PLP = pyridoxal phosphate;  NH₃ = ammonia.