Structural analysis of an HIV-1 protease I47A mutant resistant to the protease inhibitor lopinavir
Structural analysis of an HIV-1 protease I47A mutant resistant to the protease inhibitor lopinavir
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DOI：
10.1110/ps.051347405
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发表时间：
2005-07-01
期刊：
影响因子：
8
通讯作者：
Ramnarayan, K
中科院分区：
文献类型：
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作者：
Kagan, RM;Shenderovich, MD;Ramnarayan, K
我们已经确定了一种罕见的HIV-1蛋白酶（PR）突变，147 A，与高水平的耐药蛋白酶抑制剂洛匹那韦（LPV）和高敏感性蛋白酶抑制剂沙奎那韦（SQV）。在2000年底LPV上市后进行基因分型的112，198份临床样本中，有99份发现了147 A突变，但在1998年至2000年10月进行基因分型的24，426份临床样本中没有发现147 A突变。从5个147 A突变体获得的表型数据显示出对LPV的出乎意料的抗性（86-> 110倍）和对SQV的过敏性（0.1- 0.7倍）。使用我们的结构表型分析方法对这些突变体进行的分子建模和能量计算显示，相对于野生型复合物，LPV的结合能增加1.9-3.1 kcal/mol，对应于结合亲和力降低20至> 100倍，与观察到的高水平LPV抗性一致。在WT PR-LPV复合物中，Ile 47滑动链位于LPV的苯氧基乙酰基部分附近，其货车范德华相互作用显著促进配体结合。对于较小的Ala 47残基，这些相互作用丧失。计算的SQV结合能变化范围为-0.4至-1.2 kcal/mol。在突变体147 A PR-SQV复合物中，PR瓣比WT复合物中更紧密地堆积在SQV周围，导致形成额外的氢键，这增加了与表型过敏性一致的SQV的结合亲和力。PR残基47突变的出现与LPV处方的增加密切相关（斯皮尔曼相关系数r（s）= 0.96，P
We have identified a rare HIV-1 protease (PR) mutation, 147A, associated with a high level of resistance to the protease inhibitor lopinavir (LPV) and with hypersusceptibility to the protease inhibitor saquinavir (SQV). The 147A mutation was found in 99 of 112,198 clinical specimens genotyped after LPV became available in late 2000, but in none of 24,426 clinical samples genotyped from 1998 to October 2000. Phenotypic data obtained for five 147A mutants showed unexpected resistance to LPV (86- to > 110-fold) and hypersusceptibility to SQV (0.1- to 0.7-fold). Molecular modeling and energy calculations for these mutants using our structural phenotyping methodology showed an increase in the binding energy of LPV by 1.9-3.1 kcal/mol with respect to the wild type complex, corresponding to a 20- to > 100-fold decrease in binding affinity, consistent with the observed high levels of LPV resistance. In the WT PR-LPV complex, the Ile 47 slide chain is positioned close to the phenoxyacetyl moiety of LPV and its van der Waals interactions contribute significantly to the ligand binding. These interactions are lost for the smaller Ala 47 residue. Calculated binding energy changes for SQV ranged from -0.4 to -1.2 kcal/mol. In the mutant 147A PR-SQV complexes, the PR flaps are packed more tightly around SQV than in the WT complex, resulting in the formation of additional hydrogen bonds that increase binding affinity of SQV consistent with phenotypic hypersusceptibility. The emergence of mutations at PR residue 47 strongly correlates with increasing prescriptions of LPV (Spearman correlation r(s) = 0.96, P