Interactions of kinins with angiotensin I converting enzyme (kininase II).
Interactions of kinins with angiotensin I converting enzyme (kininase II).
复制标题
激肽与血管紧张素 I 转换酶（激肽酶 II）的相互作用。
DOI：
10.1016/0006-2952(83)90158-2
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发表时间：
1983
影响因子：
5.8
通讯作者：
Stewart,JM
中科院分区：
文献类型：
--
作者：
Odya,CE;Wilgis,FP;Vavrek,RJ;Stewart,JM
Angiotensin I converting enzyme (ACE) was purified to homogeneity from porcine kidney in order to determine whether iodobradykinins bind to the enzyme and, if so, whether pGlu-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro, SQ20881, a competitive ACE inhibitor, changes the conformation of the enzyme in such a way that it binds kinins with an affinity and specificity expected of a bradykinin (BK) receptor, i.e. where the BK potentiating action of SQ20881 involves an increase in the number of BK receptors due to a conformational change in ACE.125I-Labeled derivatives of [Tyr1]-kallidin and [Tyr8]-bradykinin bound to the EDTA-inhibited enzyme, and binding was inhibited by nonradioactive BK. [125I-Tyr5]-BK was not bound by the enzyme. Specificity of [125I-Tyr1-kallidin (TlK) binding was tested with forty-eight BK analogs, and the concentrations of analogs that inhibited 50% of T1K binding were determined. BK at 1.6 ± 0.3 × 10−8M inhibited 50% of T1K binding. In addition, the concentrations of analogs that decreased by 50% the rate of [3H]-Hip-Gly-Gly ([3H]-HGG) hydrolysis by ACE were assessed. BK at 1.2 ± 0.2 × 10−6M decreased the rate of [3H]-HGG hydrolysis by 50%. A comparison between these concentrations of analogs for inhibition of TlK binding and [3H]-HGG hydrolysis yielded a high correlation coefficient (r= 0.85). The specificity of ACE binding was clearly different from that expected of a BK receptor. Compounds structurally unrelated to BK, such as 5Q20881, pGlu-Lys-Trp-Ala-Pro-OH (BPP5a) and angiotensin I, inhibited T1K binding and [3H]-HGG hydrolysis by ACE.
