[3H]Captopril binding to membrane associated angiotensin converting enzyme

Biochem Biophys Res Commun. 1983 May 16;112(3):1027-33. doi: 10.1016/0006-291x(83)91721-7.


[3H]Captopril binding to membrane fractions of rat tissues is saturable and reversible with a KD of 2.4 nM. [3H]Captopril binding and angiotensin converting enzyme measured with hippuryl-L-histidine-L-leucine are distributed in parallel between different tissues and brain regions, with highest levels in the choroid plexus, lung and corpus striatum. Captopril, N-(1(S)-carboxy-3-phenyl-propyl)-L-alanyl-L-proline, N-(1(S)-carboxy-3-phenyl-propyl)-L-lysyl-L-proline, teprotide, thiorphan and S-acetylcaptopril each have similar potencies for inhibition of [3H]captopril binding and of angiotensin converting enzyme. These data strongly indicate that [3H]captopril binds selectively to angiotensin converting enzyme. [3H]Captopril binding evaluation should help clarify the localization and function of angiotensin converting enzyme and assist in defining pharmacologic actions of captopril.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Binding, Competitive
  • Brain / metabolism
  • Captopril / metabolism*
  • Cell Membrane / enzymology
  • Cell Membrane / metabolism*
  • Corpus Striatum / metabolism
  • In Vitro Techniques
  • Lung / metabolism
  • Male
  • Peptidyl-Dipeptidase A / metabolism*
  • Proline / analogs & derivatives*
  • Rats
  • Rats, Inbred Strains


  • Proline
  • Captopril
  • Peptidyl-Dipeptidase A