Kohlbrand Alysia J, Stokes Ryjul W, Sankaran Banumathi, Cohen Seth M
Department of Chemistry and Biochemistry, University of California, La Jolla, California 92093, United States.
The Berkeley Center for Structural Biology, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Biochemistry. 2024 Feb 6;63(3):264-272. doi: 10.1021/acs.biochem.3c00536. Epub 2024 Jan 8.
Vital to the treatment of influenza is the use of antivirals such as Oseltamivir (Tamiflu) and Zanamivir (Relenza); however, antiviral resistance is becoming an increasing problem for these therapeutics. The RNA-dependent RNA polymerase acidic N-terminal (PA) endonuclease, a critical component of influenza viral replication machinery, is an antiviral target that was recently validated with the approval of Baloxavir Marboxil (BXM). Despite its clinical success, BXM has demonstrated susceptibility to resistance mutations, specifically the I38T, E23K, and A36 V mutants of PA. To better understand the effects of these mutations on BXM resistance and improve the design of more robust therapeutics, this study examines key differences in protein-inhibitor interactions with two inhibitors and the I38T, E23K, and A36 V mutants. Differences in inhibitor binding were evaluated by measuring changes in binding to PA using two biophysical methods. The binding mode of two distinct inhibitors was determined crystallographically with both wild-type and mutant forms of PA. Collectively, these studies give some insight into the mechanism of antiviral resistance of these mutants.
使用诸如奥司他韦（达菲）和扎那米韦（瑞乐沙）等抗病毒药物对于流感治疗至关重要；然而，抗病毒耐药性正成为这些治疗药物日益严重的问题。RNA依赖性RNA聚合酶酸性N末端（PA）内切酶是流感病毒复制机制的关键组成部分，是一个抗病毒靶点，随着巴洛沙韦马波西酯（BXM）的获批，该靶点最近得到了验证。尽管BXM取得了临床成功，但它已显示出对耐药性突变的敏感性，特别是PA的I38T、E23K和A36V突变体。为了更好地理解这些突变对BXM耐药性的影响并改进更强大治疗药物的设计，本研究考察了两种抑制剂与I38T、E23K和A36V突变体之间蛋白质-抑制剂相互作用的关键差异。通过使用两种生物物理方法测量与PA结合的变化来评估抑制剂结合的差异。用PA的野生型和突变型晶体学确定了两种不同抑制剂的结合模式。总体而言，这些研究为这些突变体的抗病毒耐药机制提供了一些见解。
