Department of Biophysics, Federal University of São Paulo, Brazil.
Neuropeptides. 2010 Apr;44(2):139-43. doi: 10.1016/j.npep.2009.12.003. Epub 2010 Jan 12.
Angiotensin I-converting enzyme (ACE) is recognized as one of the main effector molecules involved in blood pressure regulation. In the last few years some polymorphisms of ACE such as the insertion/deletion (I/D) polymorphism have been described, but their physiologic relevance is poorly understood. In addition, few studies investigated if the specific activity of ACE domain is related to the I/D polymorphism and if it can affect other systems. The aim of this study was to establish a biochemical and functional characterization of the I/D polymorphism and correlate this with the corresponding ACE activity. For this purpose, 119 male brazilian army recruits were genotyped and their ACE plasma activities evaluated from the C- and N-terminal catalytic domains using fluorescence resonance energy transfer (FRET) peptides, specific for the C-domain (Abz-LFK(Dnp)OH), N-domain (Abz-SDK(Dnp)P-OH) and both C- and N-domains (Abz-FRK(Dnp)P-OH). Plasma kallikrein activity was measured using Z-Phe-Arg-AMC as substrate and inhibited by selective plasma kallikrein inhibitor (PKSI). Some physiological parameters previously described related to the I/D polymorphism such as handgrip strength, blood pressure, heart rate and BMI were also evaluated. The genotype distribution was II n=27, ID n=64 and DD n=28. Total plasma ACE activity of both domains in II individuals was significantly lower in comparison to ID and DD. This pattern was also observed for C- and N-domain activities. Difference between ID and DD subjects was observed only with the N-domain specific substrate. Blood pressure, heart rate, handgrip strength and BMI were similar among the genotypes. This polymorphism also affected the plasma kallikrein activity and DD group presents high activity level. Thus, our data demonstrate that the I/D ACE polymorphism affects differently both ACE domains without effects on handgrip strength. Moreover, this polymorphism influences the kallikrein-kinin system of normotensive individuals.
血管紧张素转换酶（ACE）被认为是参与血压调节的主要效应分子之一。在过去的几年中，已经描述了 ACE 的一些多态性，例如插入/缺失（I/D）多态性，但它们的生理相关性尚不清楚。此外，很少有研究调查 ACE 结构域的特定活性是否与 I/D 多态性相关，以及它是否会影响其他系统。本研究的目的是建立 I/D 多态性的生化和功能特征，并将其与相应的 ACE 活性相关联。为此，对 119 名巴西陆军新兵进行了基因分型，并使用荧光共振能量转移（FRET）肽从 C 端和 N 端催化结构域评估了 ACE 血浆活性，这些肽特异性针对 C 结构域（Abz-LFK(Dnp)OH）、N 结构域（Abz-SDK(Dnp)P-OH）和 C 结构域和 N 结构域（Abz-FRK(Dnp)P-OH）。使用 Z-Phe-Arg-AMC 作为底物测量血浆激肽释放酶活性，并使用选择性血浆激肽释放酶抑制剂（PKSI）抑制。还评估了先前描述的与 I/D 多态性相关的一些生理参数，如握力、血压、心率和 BMI。基因型分布为 II n=27、ID n=64 和 DD n=28。与 ID 和 DD 个体相比，II 个体的两个结构域的总血浆 ACE 活性明显较低。这种模式也观察到在 C 结构域和 N 结构域的活性中。仅在 N 结构域特异性底物中观察到 ID 和 DD 个体之间的差异。基因型之间的血压、心率、握力和 BMI 相似。这种多态性还影响激肽释放酶-激肽系统，DD 组表现出高活性水平。因此，我们的数据表明，I/D ACE 多态性以不同的方式影响两个 ACE 结构域，而不会影响握力。此外，这种多态性影响正常血压个体的激肽释放酶-激肽系统。
