Temperature‐induced selective death of the C‐domain within angiotensin‐converting enzyme molecule

Abstract

Somatic angiotensin-converting enzyme (ACE) consists of two homologous domains, each domain bearing a catalytic site. Di¡erential scanning calorimetry of the enzyme revealed two distinct thermal transitions with melting points at 55.3 and 70.5 ‡C. which corresponded to denaturation of C-and N-domains, respectively. Di¡erent heat stability of the domains underlies the methods of acquiring either single active N-domain or active N-domain with inactive C-domain within parent somatic ACE. Selective denaturation of C-domain supports the hypothesis of independent folding of the two domains within the ACE molecule. Modeling of ACE secondary structure revealed the di¡erence in predicted structures of the two domains, which, in turn, allowed suggestion of the region 291 33 in amino acid sequence of the N-part of the molecule as responsible for thermostability of the N-domain. ß 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

Angiotensin converting enzyme 2 (ACE2) activity in fetal calf serum: implications for cell culture research

“…In contrast, heat treatment for 30 min at 70°C completely abolished ACE2 activity in FCS. It is noteworthy that these findings are in keeping with the knowledge that the N-domain of somatic ACE, which is denatured at 70.5°C as compared to its C-domain with melting temperature of 55.3°C (Voronov et al 2002) more closely resembles ACE2 with *60% sequence similarity (Tipnis et al 2000). Although heat treatment to 70°C eliminated ACE2 activity it is unknown whether FCS treated in this way effects cell culture.…”

A Modern Understanding of the Traditional and Nontraditional Biological Functions of Angiotensin-Converting Enzyme

“…One difference between the two domains is in their thermostability, with the Ndomain being more stable than the C-domain. Specifically, the N-domain has a melting point of 70°C, which is 15°higher than the 55°C melting point of the Cdomain (Voronov et al, 2002;O'Neill et al, 2008). The increased thermostability of the N-domain may be due to the structure of amino acids 29-133, as this sequence appears to have a greater number of a helices, perhaps more glycosylation, and an increased proline content.…”

High-Resolution Crystal Structures of Drosophila melanogaster Angiotensin-Converting Enzyme in Complex with Novel Inhibitors and Antihypertensive Drugs

“…Despite sharing ∼ 60% sequence identity with the C-domain, the N-domain of sACE has its own distinctive physicochemical and functional properties. It is thermally more stable than the C-domain, 8 more resistant to proteolysis under denaturing conditions 9 and is less dependent on chloride activation as compared with the C-domain. 10,11 Substrates, such as the hemoregulatory peptide AcSDKP (acetyl-Ser-Asp-Lys-Pro), 12 angiotensin 1-7, 13 and the enkephalin precursor Met 5 -Enk-Arg 6 -Phe 7 , 14 are specific for the N-domain hydrolysis, whereas the physiological substrates bradykinin and angiotensin I are hydrolysed with similar catalytic efficiency as the C-domain.…”