Mutations in mitochondrial DNA (mtDNA) cause mitochondrial diseases, characterized by abnormal mitochondrial function. Although eliminating mutated mtDNA has potential to cure mitochondrial diseases, no chemical-based drugs in clinical trials are capable of selective modulation of mtDNA mutations. Here, we construct a class of compounds encompassing pyrrole-imidazole polyamides (PIPs), mitochondria-penetrating peptide, and chlorambucil, an adenine-specific DNA-alkylating reagent. The sequence-selective DNA binding of PIPs allows chlorambucil to alkylate mutant adenine more efficiently than other sites in mtDNA. In vitro DNA alkylation assay shows that our compound 8950A-Chb(Cl/OH) targeting a nonpathogenic point mutation in HeLa S3 cells (m.8950G>A) can specifically alkylate the mutant adenine. Furthermore, the compound reduces the mtDNA possessing the target mutation in cultured HeLa S3 cells. The programmability of PIPs to target different sequences could allow this class of compounds to be developed as designer drugs targeting pathogenic mutations associated with mitochondrial diseases in future studies.

线粒体 DNA (mtDNA) 的突变会导致线粒体疾病，其特征是线粒体功能异常。尽管消除突变的 mtDNA 有可能治愈线粒体疾病，但临床试验中没有基于化学的药物能够选择性调节 mtDNA 突变。在这里，我们构建了一类化合物，包括吡咯-咪唑聚酰胺 (PIP)、线粒体穿透肽和苯丁酸氮芥，一种腺嘌呤特异性 DNA 烷基化试剂。PIP 的序列选择性 DNA 结合允许苯丁酸氮芥比 mtDNA 中的其他位点更有效地烷基化突变腺嘌呤。体外DNA 烷基化试验表明我们的化合物8950A-Chb(Cl/OH)靶向 HeLa S3 细胞中的非致病性点突变 (m.8950G>A) 可以特异性地烷基化突变腺嘌呤。此外，该化合物可减少培养的 HeLa S3 细胞中具有靶突变的 mtDNA。PIP 针对不同序列的可编程性可以使这类化合物在未来的研究中被开发为针对与线粒体疾病相关的致病突变的设计药物。