Department of Biochemistry and Organic Chemistry, BMC, Uppsala University, Box 576, 75123 Uppsala, Sweden.
Naunyn Schmiedebergs Arch Pharmacol. 2012 Feb;385(2):219-24. doi: 10.1007/s00210-011-0718-7. Epub 2011 Dec 23.
Aliskiren is a selective renin inhibitor recently approved for use in hypertension. Efficacy duration appears longer than what would be expected based on its circulating half-life. The aim was therefore to characterize the kinetics of the interaction between aliskiren and renin. The interaction was evaluated in three assays and compared with two other renin inhibitors including remikiren. First, the inhibition of recombinant human renin was assessed by monitoring the cleavage of fluorescent substrate. Second, human plasma renin activity (PRA) was monitored by measuring generated angiotensin I over 1 h in the presence or absence of inhibitor. Finally, the affinity, association and dissociation rate constants were determined by using a surface plasmon resonance (SPR) biosensor assay. Aliskiren and remikiren were found to be equipotent inhibitors of recombinant renin activity (K(i) ≤ 0.04 nM) while compound 1 displayed a K (i) value of 1 nM. PRA was efficiently inhibited by both aliskiren and remikiren with IC₅₀ values of 0.2-0.3 nM. Remikiren and aliskiren also displayed long-lasting interactions with immobilized renin having k (off) values of 0.18 and 0.11 × 10⁻³ s⁻¹ respectively. These dissociation rate constants corresponded to residence times of 1.5 and 2.5 h, respectively, while compound 1 had a residence time lasting only 3 min. It is therefore concluded that the long-lasting interaction between aliskiren and human renin may contribute to the 24 h anti-hypertensive effect seen in clinical trials and possibly also to target-mediated drug disposition.
阿利克仑是一种新批准用于治疗高血压的选择性肾素抑制剂。其疗效持续时间似乎比根据其循环半衰期所预期的要长。因此，本研究旨在研究阿利克仑与肾素相互作用的动力学特征。采用三种检测方法评估了相互作用，并与另外两种肾素抑制剂（包括雷米克林）进行了比较。首先，通过监测荧光底物的切割来评估重组人肾素的抑制作用。其次，通过在存在或不存在抑制剂的情况下测量 1 小时内生成的血管紧张素 I 来监测人血浆肾素活性（PRA）。最后，通过表面等离子体共振（SPR）生物传感器检测方法确定亲和力、缔合和解离速率常数。发现阿利克仑和雷米克林对重组肾素活性具有同等抑制作用（K(i)≤0.04 nM），而化合物 1 的 K(i)值为 1 nM。阿利克仑和雷米克林均能有效抑制 PRA，IC₅₀值为 0.2-0.3 nM。雷米克林和阿利克仑与固定化肾素也表现出持久的相互作用，其 k (off)值分别为 0.18 和 0.11×10⁻³ s⁻¹。这些解离速率常数分别对应于 1.5 和 2.5 h 的停留时间，而化合物 1 的停留时间仅持续 3 min。因此，阿利克仑与人类肾素之间的持久相互作用可能有助于在临床试验中观察到的 24 小时抗高血压作用，并且可能也有助于靶介导的药物处置。
