传感器类型
表面等离子共振(SPR)生物传感器
检测对象
HIV-1 非核苷逆转录酶抑制剂(NNRTIs,化合物库);样品基质:PBS-P 缓冲液/5% DMSO
检测原理
HIV-1 RT 变体经 EDC/NHS 胺偶联固定于 CM5 芯片,NNRTI 注入后与 RT 的 NNRTI 变构位点结合,形成酶-抑制剂复合物,使界面质量与折射率增加,SPR 响应(RU)上升;解离阶段信号下降。系统以 DA3 参考区扣除非特异信号,并按分子量归一化。取解离后 5 s 报告点 E 表示结合量/亲和,40 s 与 440 s 报告点比值 DR 表示解离速率;Ecorr≥100 RU 且 DR≥0.8 用于筛选高亲和、慢解离化合物。竞争实验先注入 MIV-170 占据 NNRTI 位点,再注入候选物,通过信号是否增加判断是否竞争结合。方法无化学放大,依赖实时 SPR 信号。
检测灵敏度
未报告LOD、线性范围、灵敏度斜率或相关系数。
效应效果
方法在正反向重复筛选中生成6400条化合物传感器图,3211个正信号中筛出12个单靶点命中(1.5%),其中2个化合物对4个RT变体均满足阈值,最终命中率0.25%。降低DR阈值至0.6仅增加18个化合物(总30个,3.8%),最终命中不变。MV026340与MIV-170竞争结合NNRTI位点,IC50为5.2–16 nM,EC50为2.5–8.2 nM,优于或接近efavirenz/nevirapine;MV026119无抑制。作者认为该SPR动力学筛选可并行获得多靶点高分辨率实时数据,适用于寻找特定动力学药物。
传感器的构成
- 基底/换能器:BIACORE A100 金膜 SPR 芯片,提供表面等离子共振换能
- 修饰层:CM5 羧甲基葡聚糖层,提供羧基用于共价偶联
- 活化层:EDC/NHS 活化 CM5 羧基,形成氨基反应性酯
- 封闭剂:乙醇胺封闭未反应酯,减少非特异结合
- 识别元件:HIV-1 RT 变体(Wt、L100I、Y181C、K103N)胺偶联固定,作为靶标蛋白
- 信号标记物:无外源标记物,SPR 直接检测界面折射率变化
- 参考面:DA3 仅 EDC/NHS 活化并乙醇胺封闭,用于参考扣除
中文摘要
本研究利用表面等离子共振(SPR)生物传感器,将800个HIV-1非核苷逆转录酶抑制剂(NNRTIs)先导优化化合物库与4种临床相关HIV-1逆转录酶(RT)变体(Wt、L100I、Y181C、K103N)并行筛选,旨在发现可用于局部微杀菌剂、能预防多种临床重要HIV-1毒株传播的抑制剂。作者假设有效化合物应对多个靶标变体具有高亲和力和慢解离速率。为高效分析大量实时传感器图,先提取3个选定时间点信号,识别对全部酶变体均呈高亲和和慢解离的化合物,再目视完整传感器图确认命中。两种结构无关化合物满足命中标准,但仅1种对全部4种酶变体均能与已知NNRTI竞争结合NNRTI位点、抑制HIV-1 RT活性并抑制细胞培养中HIV-1复制。该方法可并行获得多靶点高分辨率实时动力学数据,适用于发现具有特定动力学特征、对治疗效果至关重要的化合物。
英文摘要
A lead optimization library consisting of 800 HIV-1 nonnucleoside reverse transcriptase inhibitors (NNRTIs) was screened in parallel against 4 clinically relevant variants of HIV-1 RT (Wt, L100I, Y181C, and K103N) using a surface plasmon resonance-based biosensor. The aim was to identify inhibitors suitable in specific topical microbicides efficient for preventing the transmission of a range of clinically significant strains of HIV-1. The authors hypothesized that such compounds should have high affinity and slow dissociation rates for multiple variants of the target. To efficiently analyze the large amount of real-time data (sensorgrams) that were generated in the screening, they initially used signals from 3 selected time points to identify compounds with high affinity and slow dissociation for the complete panel of enzyme variants. Hits were confirmed by visually inspecting the complete sensorgrams. Two structurally unrelated compounds fulfilled the hit criteria, but only 1 compound was found to (a) compete with a known NNRTI for binding to the NNRTI site, (b) inhibit HIV-1 RT activity, and (c) inhibit HIV-1 replication in cell culture, for all 4 enzyme variants. This novel screening methodology offers high-resolution real-time kinetic data for multiple targets in parallel. It is expected to have broad applicability for the discovery of compounds with defined kinetic profiles, crucial for optimal therapeutic effects.