Enalaprilat is a competitive inhibitor of the angiotensin-converting enzyme (ACE), which cleaves the blood-pressure regulating peptide angiotensin I.
ACE has a KM = 52 μM for angiotensin I, which is present in plasma at a concentration of 75 μM.
When enalaprilat is present at 2.4 nM, the activity of ACE in plasma is 10% of its uninhibited activity.
What is the value of KI for enalaprilat?