Medical Scientist Training Program , Mayo Clinic College of Medicine and Science , Rochester , Minnesota 55905 , United States.
Department of Biochemistry and Molecular Biology , Mayo Clinic College of Medicine and Science , Rochester , Minnesota 55905 , United States.
J Am Chem Soc. 2019 Nov 20;141(46):18375-18379. doi: 10.1021/jacs.9b06736. Epub 2019 Nov 12.
Combinatorial chemistry drives the biological generation of protein structural diversity in antibodies and T-cell receptors. When applied to nucleic acids, vast engineered random libraries of DNA and RNA strands allow selection of affinity reagents ("aptamers") against molecular targets. Selection involves cycles rewarding target binding affinity with amplification. Despite the success of this approach, delivery of selected aptamers across cell membranes and to specific subcellular compartments is an unmet need in chemical biology. Here, we address this challenge, demonstrating in vitro selection of DNA aptamers capable of homing to nuclei of cultured cells without transfection agents or viral transduction. Selection of such folded karyophilic DNA aptamers (∼100 nucleotides) is achieved by a biosensor strategy that rewards exposure to nuclear DNA ligase. Identified DNA molecules are preferentially delivered to cell nuclei within minutes. Related strategies can be envisioned to select aptamers that home to other subcellular compartments.
组合化学推动了抗体和 T 细胞受体中蛋白质结构多样性的生物学产生。当应用于核酸时，经过工程设计的大量 DNA 和 RNA 链随机文库可以选择针对分子靶标的亲和试剂（“适体”）。选择涉及循环奖励靶结合亲和力与扩增。尽管这种方法取得了成功，但在化学生物学中，穿过细胞膜并递送到特定亚细胞隔室的选定适体仍然是一个未满足的需求。在这里，我们解决了这一挑战，证明了在没有转染剂或病毒转导的情况下，体外选择能够归巢到培养细胞细胞核的 DNA 适体。通过一种生物传感器策略来选择这种折叠亲核 DNA 适体（约 100 个核苷酸），该策略奖励与核 DNA 连接酶的暴露。鉴定的 DNA 分子在几分钟内优先递送到细胞核内。可以设想相关策略来选择归巢到其他亚细胞隔室的适体。
