Bz-Ala-Arg TFA is a dipeptide. Bz-Ala-Arg TFA is also a spectrophotometric substrate (0.4 M pyridine formate, pH 4.25) of human pancreatic carboxypeptidase B and plasma carboxypeptidase N. Bz-Ala-Arg TFA can be used to screen competitive inhibitors of these two enzymes.
References:
[1]. McKay TJ, et al. Comparative studies on human carboxypeptidases B and N. Arch Biochem Biops. 1979 Oct 15;197(2):487-92.