作者:Lauge Farnaes、James J. La Clair、William Fenical
DOI:10.1039/c3ob41355a
日期:——
The intracellular localization and target of the napyradiomycin congeners CNQ525.510B and A80815C were explored using an immunoaffinity fluorescence (IAF) approach. Semi-synthetic methods were used to prepare probes from napyradiomycin CNQ525.510B and derivative A80815C. The results of confocal microscopy indicated that probes from both natural products localized predominantly within the endoplasmic reticulum (ER) of HCT-116 human colon carcinoma cells. Parallel immunoaffinity precipitation efforts using a monoclonal antibody designed against the IAF tag, resulted in the isolation of an Hsp90 family member. This protein was identified as human Grp94 (hGrp94), by its specific mass spectral signature. This observation was validated by Western blot analyses and by the result of an in vitro Grp94 binding assay. The fact that the napyradiomycins CNQ525.510B and A80815C bind to hGrp94, and their associated probes localize within the ER, suggest the use of these materials as molecular probes for monitoring ER-based chaperone function.
使用免疫亲和荧光(IAF)方法研究了萘拉霉素同系物CNQ525.510B和A80815C的细胞内定位和靶向。使用半合成方法从萘拉霉素CNQ525.510B和衍生物A80815C制备探针。共聚焦显微镜的结果表明,这两种天然产物制备的探针主要定位在HCT-116人结肠癌细胞的内质网(ER)内。使用针对IAF标签设计的一种单克隆抗体进行平行免疫亲和沉淀,结果分离出一种Hsp90家族成员。通过其特定的质谱特征,该蛋白被鉴定为人类Grp94(hGrp94)。这一观察结果通过蛋白质印迹分析和体外Grp94结合分析的结果得到了验证。萘拉霉素CNQ525.510B和A80815C与hGrp94结合,其相关探针定位在内质网内,这表明这些材料可用作监测基于内质网的伴侣功能的分子探针。