N-Acetyl-Ser-Asp-Lys-Pro (TFA) is an endogenous tetrapeptide that is naturally produced in the bone marrow. It serves as a specific substrate for the N-terminal site of ACE, the enzyme responsible for angiotensin converting activity.
RXP 407 is a selective inhibitor of the N-domain of angiotensin I-converting enzyme. RXP 407 blocks the degradation of hemoregulatory peptide acetyl-Ser-Asp-Lys-Pro with no effect on angiotensin I hydrolysis in vivo.