Riley Blake T, Ilyichova Olga, Costa Mauricio G S, Porebski Benjamin T, de Veer Simon J, Swedberg Joakim E, Kass Itamar, Harris Jonathan M, Hoke David E, Buckle Ashley M
Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia.
Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Sci Rep. 2016 Oct 21;6:35385. doi: 10.1038/srep35385.
The kallikrein-related peptidase (KLK) family of proteases is involved in many aspects of human health and disease. One member of this family, KLK4, has been implicated in cancer development and metastasis. Understanding mechanisms of inactivation are critical to developing selective KLK4 inhibitors. We have determined the X-ray crystal structures of KLK4 in complex with both sunflower trypsin inhibitor-1 (SFTI-1) and a rationally designed SFTI-1 derivative to atomic (~1 Å) resolution, as well as with bound nickel. These structures offer a structural rationalization for the potency and selectivity of these inhibitors, and together with MD simulation and computational analysis, reveal a dynamic pathway between the metal binding exosite and the active site, providing key details of a previously proposed allosteric mode of inhibition. Collectively, this work provides insight into both direct and indirect mechanisms of inhibition for KLK4 that have broad implications for the enzymology of the serine protease superfamily, and may potentially be exploited for the design of therapeutic inhibitors.
激肽释放酶相关肽酶（KLK）蛋白酶家族涉及人类健康和疾病的许多方面。该家族的一个成员KLK4与癌症的发生和转移有关。了解其失活机制对于开发选择性KLK4抑制剂至关重要。我们已经确定了与向日葵胰蛋白酶抑制剂-1（SFTI-1）和合理设计的SFTI-1衍生物复合的KLK4的X射线晶体结构，分辨率达到原子级（约1Å），以及与结合镍的结构。这些结构为这些抑制剂的效力和选择性提供了结构上的合理解释，并且与分子动力学模拟和计算分析一起，揭示了金属结合外位点和活性位点之间的动态途径，提供了先前提出的变构抑制模式的关键细节。总的来说，这项工作深入了解了KLK4的直接和间接抑制机制，这对丝氨酸蛋白酶超家族的酶学具有广泛影响，并且可能被用于设计治疗性抑制剂。
