Silva Elany B, Jiang Zhenze, Liu Chenxi, Fajtová Pavla, Teixeira Thaiz R, de Castro Fiorini Maia Giovana, Liu Lawrence J, El-Sakkary Nelly, Skinner Danielle E, Syed Ali, Wang Steven C, Caffrey Conor R, O'Donoghue Anthony J
Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA.
Department of Biochemistry & Immunology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Protein Sci. 2025 Jun;34(6):e70180. doi: 10.1002/pro.70180.
Schistosomiasis, a neglected tropical disease infecting over 200 million people globally, has limited therapeutic options. The 20S proteasome is a validated drug target for many parasitic infections, including those caused by Plasmodium and Leishmania, and we have previously demonstrated antischistosomal activity with inhibitors targeting Schistosoma mansoni 20S proteasome (Sm20S). Here, we developed optimized subunit-specific substrates for Sm20S based on data generated by Multiplex Substrate Profiling by Mass Spectrometry (MSP-MS). These substrates exhibit 9-fold or more improved activity compared to traditional human constitutive 20S proteasome (c20S) substrates. The optimized substrates also eliminated the need for extensive Sm20S purification, as robust enzyme activity could be detected in parasite extracts following an ammonium sulfate precipitation step. Finally, we show that the substrate and inhibition profiles for the 20S proteasome from the three medically important schistosome species are similar. This suggests that Sm20S-focused inhibitor development can be efficiently extrapolated to the other schistosome species, leading to significant time and resource savings.
血吸虫病是一种被忽视的热带疾病，全球感染人数超过2亿，其治疗选择有限。20S蛋白酶体是许多寄生虫感染（包括由疟原虫和利什曼原虫引起的感染）的已验证药物靶点，我们之前已经证明，靶向曼氏血吸虫20S蛋白酶体（Sm20S）的抑制剂具有抗血吸虫活性。在此，我们基于质谱多重底物分析（MSP-MS）生成的数据，开发了针对Sm20S的优化亚基特异性底物。与传统的人类组成型20S蛋白酶体（c20S）底物相比，这些底物的活性提高了9倍或更多。优化后的底物还无需进行大量的Sm20S纯化，因为在硫酸铵沉淀步骤后，在寄生虫提取物中可以检测到强大的酶活性。最后，我们表明，三种医学上重要的血吸虫物种的20S蛋白酶体的底物和抑制谱相似。这表明，以Sm20S为重点的抑制剂开发可以有效地外推到其他血吸虫物种，从而显著节省时间和资源。
