Structural and Mechanistic Bases of Viral Resistance to HIV-1 Capsid Inhibitor Lenacapavir.
Structural and Mechanistic Bases of Viral Resistance to HIV-1 Capsid Inhibitor Lenacapavir.
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Lenacapavir(LEN)是一种长效、高效的HIV-1衣壳(CA)抑制剂。在LEN的遗传压力下，病毒变异株的进化确定Q67H、N74D和Q67H/N74D CA替换是主要的抗性相关突变(RAM)。在这里，我们确定了在没有LEN和存在LEN的情况下包含这些RAM的CA六聚体的高分辨率结构。我们的发现表明，Q67H的变化诱导了构象转换，这对抑制剂的结合产生了不利的影响。在未连接的蛋白质中，His67侧链通过突出到抑制剂结合口袋而采用闭合构象，从而对LEN产生空间位阻。在抑制剂结合后，His67侧链重新定位为开放构象，与WT蛋白中的Gln67侧链非常相似。我们认为，从封闭构象到开放构象的转换是适应LEN所必需的，这解释了相对于Q67H CA变异体抑制活性降低的原因。N74D的CA改变导致CA和LEN之间失去直接氢键和诱导静电斥力。Q67H/N74D双替换表现出各自单一氨基酸变化的累积效应。LEN与CA六聚体结合动力学的研究表明，Q67H和N74D CA的变化主要通过影响解离速率常数(Koff)而对抑制剂结合亲和力(Kd)产生不利影响。我们利用这些结构性和机械性的发现对LEN进行了合理的修改。所得类似物对Q67H/N74D病毒变异株显示出更强的效力。因此，我们的研究为开发具有更强的耐药性屏障的第二代抑制剂提供了一种手段。
Lenacapavir (LEN) is a long-acting, highly potent HIV-1 capsid (CA) inhibitor. The evolution of viral variants under the genetic pressure of LEN identified Q67H, N74D, and Q67H/N74D CA substitutions as the main resistance associated mutations (RAMs). Here, we determined high-resolution structures of CA hexamers containing these RAMs in the absence and presence of LEN. Our findings reveal that the Q67H change induces a conformational switch, which adversely affects the inhibitor binding. In the unliganded protein, the His67 side chain adopts the closed conformation by projecting into the inhibitor binding pocket and thereby creating steric hindrance with respect to LEN. Upon the inhibitor binding, the His67 side chain repositions to the open conformation that closely resembles the Gln67 side chain in the WT protein. We propose that the switch from the closed conformation to the open conformation, which is needed to accommodate LEN, accounts for the reduced inhibitor potency with respect to the Q67H CA variant. The N74D CA change results in the loss of a direct hydrogen bond and in induced electrostatic repulsions between CA and LEN. The double Q67H/N74D substitutions exhibited cumulative effects of respective single amino acid changes. An examination of LEN binding kinetics to CA hexamers revealed that Q67H and N74D CA changes adversely influenced the inhibitor binding affinity (KD) by primarily affecting the dissociation rate constant (koff). We used these structural and mechanistic findings to rationally modify LEN. The resulting analog exhibited increased potency against the Q67H/N74D viral variant. Thus, our studies provide a means for the development of second-generation inhibitors with enhanced barriers to resistance.
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影响因子：
6.7
作者：
Price AJ;Fletcher AJ;Schaller T;Elliott T;Lee K;KewalRamani VN;Chin JW;Towers GJ;James LC
通讯作者：
James LC
影响因子：
5.8
作者：
Selyutina A;Hu P;Miller S;Simons LM;Yu HJ;Hultquist JF;Lee K;KewalRamani VN;Diaz-Griffero F
通讯作者：
Diaz-Griffero F
影响因子：
5.4
作者：
Sowd GA;Shi J;Aiken C
通讯作者：
Aiken C
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
158.5
作者：
Segal-Maurer, Sorana;DeJesus, Edwin;Molina, Jean-Michel
通讯作者：
Molina, Jean-Michel