Characterization of Bovine Atrial Angiotensin-Converting Enzyme

E. V. Garats¹, I. I. Nikolskaya¹, P. V. Binevski¹, V. F. Pozdnev², and O. A. Kost^1*

¹School of Chemistry, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-5417; E-mail: kost@enzyme.chem.msu.ru

²Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, ul. Pogodinskaya 10, Moscow, 119832 Russia; fax: (095) 245-0857; E-mail: pos@ibmh.msk.su

^* To whom correspondence should be addressed.

Received June 30, 2000

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Bovine atrial angiotensin-converting enzyme (ACE) was purified to electrophoretic homogeneity. The purification procedure included ion-exchange chromatography on DEAE-Toyopearl 650M, affinity chromatography on lisinopril-agarose and gel filtration on Sephadex G-100. The bovine atrial ACE exhibited similar sensitivities to inhibition by lisinopril and captopril as lung ACE (the K_i values for the atrial and lung enzymes differed insignificantly). However, the kinetic parameters of hydrolysis of some synthetic tripeptide substrates (FA-Phe-Gly-Gly, FA-Phe-Phe-Arg, Cbz-Phe-His-Leu, Hip-His-Leu) catalyzed by bovine atrial and lung ACE varied to a greater extent. The enzymes were also characterized by some differences in activation by chloride, nitrate, and sulfate anions. These data support the hypothesis of tissue specificity of ACEs.

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KEY WORDS: angiotensin converting enzyme, tissue specificity, bovine atrium, catalytic properties, tissue specificity

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