Surface Plasmon Resonance Analysis of the Binding Mechanism of Pharmacological and Peptidic Inhibitors to Human Somatic Angiotensin I-Converting Enzyme

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• 作者：Fa茂za Zidane ; Gabrielle Zeder-Lutz ; Dani猫le Altschuh ; Jean-Michel Girardet ; Laurent Miclo ; Catherine Corbier ; C茅line Cakir-Kiefer
• 刊名：Biochemistry
• 出版年：2013
• 出版时间：December 3, 2013
• 年：2013
• 卷：52
• 期：48
• 页码：8722-8731
• 全文大小：430K
• 年卷期：v.52,no.48(December 3, 2013)
• ISSN：1520-4995

文摘

Somatic angiotensin I-converting enzyme (ACE) possesses two catalytic domains and plays a major role in the regulation of blood pressure, thus representing a therapeutic target for the treatment of hypertension. We present a comprehensive surface plasmon resonance (SPR) study of the interaction of human somatic ACE with the pharmacological inhibitors captopril and lisinopril, the bradykinin potentiating peptide BPP-11b, and the food peptidic inhibitors from bovine 伪_s2-casein, F¹⁷⁴ALPQYLK¹⁸¹ and F¹⁷⁴ALPQY¹⁷⁹. SPR binding curves recorded with the high potency inhibitors captopril, lisinopril, and BPP-11b were evaluated both by regression analysis and by kinetic distribution analysis. The results indicated that captopril and lisinopril bound ACE with two K_D鈥檚 differing by a factor 10鈥?0 and >30, respectively (lowest K_D = 0.1鈥?.3 nM for both inhibitors). This shows, for the first time in a direct binding assay with the two-domain enzyme, the existence of two binding modes of the pharmacological inhibitors, presumably with the two ACE domains. The BPP-11b鈥揂CE binding curves were complex but showed a predominant interaction with K_D in the nanomolar range. The caseinopeptides, known to inhibit ACE with an IC₅₀ of 4.3 渭M, bound to ACE with K_D = 3鈥? 渭M. Mapping of the F¹⁷⁴ALPQY¹⁷⁹ binding site on ACE by sequential binding studies using captopril or BPP-11b indicated that it bound to (or near) the two active sites of ACE, in agreement with the stoichiometry of 2 determined from data fitting. Our results provide a detailed characterization of ACE-inhibitor binding modes and validate SPR for predicting the inhibitory potential of new compounds.