As a new type of cathepsin K inhibitor, azadipeptide nitriles have the characteristics of proteolytic stability and excellent inhibitory activity, but they exhibit barely any satisfactory selectivity. Great efforts have focused on improving their selectivity toward cathepsin K. In this sequential study, we report the further structural optimization, synthesis, molecular modeling, and in vitro enzymatic assays of a new series of potent and selective inhibitors of cathepsin K without the P2–P3 amide linker. Significant selective improvements were achieved for cathepsin K over L, S and B, and a triaryl meta-product 13′ possessed the favorable balance between potency (Ki = 0.29 nM) and selectivity of cathepsin K over cathepsin L (320-fold), S (1784-fold) and B (8566-fold). We undertook a covalent protein–ligand docking study to explain the improved selectivity of several representative compounds. Such a selectivity improvement would be useful to avoid harmful side effects in practical applications of these compounds.
偶氮二肽
腈类化合物作为一种新型的 cathepsin K
抑制剂,具有蛋白
水解稳定性和优异的抑制活性,但它们几乎没有表现出令人满意的选择性。在这项连续性研究中,我们报告了一系列不含 P2-P3 酰胺连接体的新型强效、选择性 cathepsin K
抑制剂的结构优化、合成、分子建模和体外酶学实验。我们显著提高了
酪蛋白酶 K 对
酪蛋白酶 L、S 和 B 的选择性,三芳基元产物 13′ 在
酪蛋白酶 K 的效力(Ki = 0.29 nM)和选择性之间取得了有利的平衡,
酪蛋白酶 K 的选择性比
酪蛋白酶 L(320 倍)、S(1784 倍)和 B(8566 倍)高。我们进行了共价蛋白质-
配体对接研究,以解释几种代表性化合物选择性提高的原因。这种选择性的提高有助于避免这些化合物在实际应用中产生有害的副作用。