1.Presence of angiotensin converting enzyme (ACE) activity in serum of amphibian: comparison with ACE activity of mammalian serum.
Miano A1, Bramucci M, Murri O, Quassinti L, Maccari E, Zerani M, Gobbetti A, Amici D. Acta Physiol Scand. 1997 Jul;160(3):277-82.
The occurrence of angiotensin converting enzyme (EC 3.4.15.1; ACE) was demonstrated for the first time in serum of newt (Triturus carnifex) and frog (Rana esculenta). The enzymatic activity was evidenced following hydrolysis of N-[3-(2-furyl) acryloyl]L-phenylalanyl glycyl glycine (FAPGG), a synthetic substrate of ACE. The serum enzyme liberated N-[3-(2-furyl) acryloyl]L-phenylalanine (FAP) from FAPGG. The properties of the amphibian serum enzymes were compared with those of swine. The amphibian serum FAPGG hydrolysing activities were inhibited by typical ACE inhibitors, captopril and lisinopril. The optimum of pH was 8.3 at 10 and 37 degrees C and the temperature optimum was 45 degrees C. The values were similar to those of swine serum. The FAPGG Michaelis-Menten constants (K(m)) at 37 degrees C of amphibian serum enzymes (0.337 mM and 0.282 mM for frog and newt, respectively) were lower than that of swine (1.305 mM), but close to human serum enzyme.
2.Evidence for the negative cooperativity of the two active sites within bovine somatic angiotensin-converting enzyme.
Binevski PV1, Sizova EA, Pozdnev VF, Kost OA. FEBS Lett. 2003 Aug 28;550(1-3):84-8.
The somatic isoform of angiotensin-converting enzyme (ACE) consists of two homologous domains (N- and C-domains), each bearing a catalytic site. We have used the two-domain ACE form and its individual domains to compare characteristics of different domains and to probe mutual functioning of the two active sites within a bovine ACE molecule. The substrate Cbz-Phe-His-Leu (N-carbobenzoxy-L-phenylalanyl-L-histidyl-L-leucine; from the panel of seven) was hydrolyzed faster by the N-domain, the substrates FA-Phe-Gly-Gly (N-(3-[2-furyl]acryloyl)-L-phenylalanyl-glycyl-glycine) and Hip-His-Leu (N-benzoyl-glycyl-L-histidyl-L-leucine) were hydrolyzed by both domains with equal rates, while other substrates were preferentially hydrolyzed by the C-domain. The inhibitor captopril ((2S)-1-(3-mercapto-2-methylpropionyl)-L-proline) bound to the N-domain more effectively than to the C-domain, whereas lisinopril ((S)-N(alpha)-(1-carboxy-3-phenylpropyl)-L-lysyl-L-proline) bound to equal extent with all ACE forms.
3.Purified angiotensin converting enzyme from Rana esculenta ovary influences ovarian steroidogenesis in vitro.
Miano A1, Quassinti L, Maccari E, Murri O, Amici D, Bramucci M. J Physiol Biochem. 2003 Dec;59(4):269-76.
The aim of the present study was to purify and characterize angiotensin-converting enzyme (ACE) present in frog ovary (Rana esculenta). Detergent and trypsin-extracted enzymes were purified using a one-step process, consisting of affinity chromatography on lisinopril coupled to Sepharose 6B. The molecular mass was 150 kDa for both detergent-extracted and trypsin-extracted enzyme. The specific activity of detergent-extracted and trypsin-extracted ACE was 294 U mg(-1) and 326 U mg(-1) respectively. The optimum pH range was from 7-8.5 at 37 degrees C and the optimum temperature was 50 degrees C. Optimum chloride concentration was about 200 mM for synthetic substrate FAPGG (N-[3-(2-furyl)acryloyl] L-phenylalanyl glycyl glycine) and angiotensin I, and 10 mM for bradykinin. The Km and Kcat values for FAPGG were 0.608 +/- 0.07 mM and 249 sec(-1) respectively and I50 values for captopril and lisinopril, two specific ACE inhibitors, were 68 +/- 12.
![N-[3-(2-Furyl)acryloyl]-Phe-Gly-Gly](https://resource.bocsci.com/structure/64967-39-1.gif)
