Polymorphic inhibition of human angiotensin I-converting enzyme by enalaprilat

Many individuals possess an allele of the angiotensin I-converting enzyme (ACE) gene, which contains an extra 287-kb fragment in intron 16 (Rigat et al. 1992). Although the functionality of this fragment is at present unclear, the absence (deletion, D) or presence (insertion, I) of this fragment appears to be related to both the amount and activity of circulating ACE. This paper reports the possible polymorphic response of ACE to the ACE inhibitor enalaprilat in 54 normal Chinese subjects that is independent of the I/D polymorphism. The kinetics of ACE inhibition with enalaprilat was studied in serum from 54 normal Chinese subjects. Enalaprilat appKi ranged between 0.46 and 2.16 nM. An antimode was observed at 1.4 nM. Four subjects could be characterized as being poor responders to enalaprilat.