Angiotensin-convertingenzyme(ACE)isazinc-containingdipeptidylcarboxypeptidasewidelydistributedinmammaliantissuesandisthoughttoplayacriticalroleinbloodpressureregulation.Thepredictedproteinisidentical,fromresidue37toitsCterminus,tothesecondhalforC-terminaldomainoftheendothelialACEsequence.Theproteinsequenceinferredconsistsofa732-residuepreproteinincludinga31-residuesignalpeptide.Thematurepolypeptidehasamolecularweightof80,073.AlthoughACEhasbeenstudiedprimarilyinthecontextofitsroleinbloodpressureregulation,thiswidelydistributedenzymehasmanyotherphysiologicalfunctions.TheACEgeneencodestwoisozymes.Thesomaticisozymeisexpressedinmanytissues,includingvascularendothelialcells,renalepithelialcells,andtesticularLeydigcells,whereasthetesticularorgerminalangiotensin-convertingenzymeisexpressedonlyinsperm.ThestandardproductusedinthiskitisrecombinanthumanACE,consistingof30-1261aminoacidswiththemolecularmassof120KDa.