Chandrasekaran Sambamurthy, Veronica Jalaja, Gundampati Ravi Kumar, Sundar Shyam, Maurya Radheshyam
a Department of Animal Biology , University of Hyderabad , Hyderabad , Andhra Pradesh , India .
b Molecular Biology Unit , Institute of Medical Sciences, Banaras Hindu University , Varanasi , Uttar Pradesh , India , and.
J Enzyme Inhib Med Chem. 2016 Dec;31(6):1029-37. doi: 10.3109/14756366.2015.1088841. Epub 2015 Sep 25.
Withaferin A is an abundant withanolide present in Withania somnifera leaves and to some extent in roots. It has been known for its profound anti-cancer properties, but its role in counteracting the Leishmania donovani infection has to be explored. Pteridine reductase 1 (PTR1) is involved in pteridine salvage and an important enzyme for the parasite growth, which could be targeted for the development of an efficient antileishmanial drug. We employed molecular docking studies to identify the binding mode of withaferin A with PTR1 in silico. We further cloned, expressed, and purified PTR1 of L. donovani and performed the enzyme kinetics using the Michaelis-Menten equation and enzyme inhibition studies with withaferin A by plotting the Lineweaver-Burk graph, which followed an uncompetitive mode of inhibition. We also showed the inhibition of the enzyme in the crude lysate of treated parasites. Thus, our study contributes towards understanding the mode of action of withaferin A against L. donovani parasite.
睡茄内酯A是一种存在于印度人参叶中且在一定程度上也存在于根中的丰富的睡茄内酯。它因其具有显著的抗癌特性而闻名，但它在对抗杜氏利什曼原虫感染中的作用还有待探索。蝶啶还原酶1（PTR1）参与蝶啶补救途径，是寄生虫生长的一种重要酶，可作为开发高效抗利什曼原虫药物的靶点。我们采用分子对接研究在计算机上确定睡茄内酯A与PTR1的结合模式。我们进一步克隆、表达并纯化了杜氏利什曼原虫的PTR1，并使用米氏方程进行酶动力学研究，通过绘制Lineweaver - Burk图对睡茄内酯A进行酶抑制研究，其呈现非竞争性抑制模式。我们还展示了在经处理的寄生虫粗裂解物中该酶受到抑制。因此，我们的研究有助于理解睡茄内酯A对杜氏利什曼原虫的作用模式。
