L-γ-Glutamyl-p-nitroanilide (67953-08-6; GPNA) is a substrate for γ-glutamyl transpeptidase. GPNA is used for the determination of γ-glutamyl transpeptidase hydrolytic activity via spectrophotometric monitoring of p-nitroaniline released by the action of the enzyme on GPNA.1 GPNA has also been shown to be an inhibitor of glutamine uptake – solute-linked carrier family A1 member 5 (SLC1A5).2?Cellular uptake of L-glutamine (regulated by SLC1A5) is a rate-limiting step that activates mTOR and is, thus, an interesting cancer chemotherapy target.3
1) Meister?et al. (1981),?γ-Glutamyl transpeptidase; Methods Enzymol.,?77?237
2) Esslinger?et al. (2005),?N-gamma-aryl glutamine analogues as probes of the ASCT2 neutral amino acid transporter binding site; Bioorg. Med. Chem.,?13?1111
3) Nicklin?et al. (2012),?Bidirectional Transport of Amino Acid Regulates mTOR and Autophagy; Cell,?136?521
