Branched cationic peptides for gene delivery:: Role of type and number of cationic residues in formation and in vitro activity of DNA polyplexes
Branched cationic peptides for gene delivery:: Role of type and number of cationic residues in formation and in vitro activity of DNA polyplexes
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DOI：
10.1089/10430349950019101
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发表时间：
1999-01-20
影响因子：
4.2
通讯作者：
Szoka, FC
中科院分区：
文献类型：
--
作者：
Plank, C;Tang, MX;Szoka, FC
为了检验合成肽作为受体介导的基因传递的dna结合和压缩剂的适用性，我们合成并表征了一系列分支寡核苷酸，它们在dna结合部分的阳离子氨基酸的数量和类型（赖氨酸、精氨酸、鸟氨酸）上不同。这些肽被设计成支链分子，通过间隔剂提供偶联位点，使效应体在与dna结合片段的灵活距离上附着。这种设计为DNA结合片段的肽主链提供了扭转灵活性，以最大限度地提高阳离子-DNA磷酸盐相互作用，并最大限度地减少效应物干扰DNA结合的可能性。支链肽结合DNA的亲和力随着阳离子基团数量的增加而增加。通过溴化乙锭置换试验、动态光散射和电子显微镜来判断，肽将DNA压缩成微粒结构。总的来说，由于阳离子侧链的变化，DNA结合和压实的差异是适度的，其等级顺序为精氨酸基、赖氨酸基、鸟腈基。色氨酸掺入dna结合片段对表观结合亲和力没有明显影响，但明显降低了肽的dna压实效力。与聚赖氨酸相比，多肽及其DNA复合物是补体系统的弱激活剂。补体被辛精氨酸肽激活比被辛精氨酸肽诱导的激活更强。在氯喹存在的情况下，K562细胞的转移感染证明，微粒肽- dna复合物适合于受体介导的基因传递。在体外基因传递中获得的结果表明，至少需要6到8个阳离子氨基酸的链长度才能将DNA压缩成在受体介导的基因传递中具有活性的结构。
To examine the suitability of synthetic peptides as DNA-binding and -compacting agents for receptor-mediated gene delivery, we have synthesized and characterized a series of branched oligocationic peptides that differ in the number and type (lysine, arginine, ornithine) of cationic amino acids in the DNA-binding moiety. The peptides were designed as branched molecules to provide a coupling site via a spacer for the attachment of effecters at a flexible distance from the DNA-binding moiety. This design provides torsional flexibility in the peptide backbone of the DNA-binding moiety to maximize cation-DNA phosphate interactions and also minimizes the potential for interference by the effector with DNA binding. The branched peptides bind DNA with affinities that increase with the number of cationic groups. The peptides compact DNA into microparticulate structures as judged by an ethidium bromide displacement assay, dynamic light scattering, and electron microscopy. In general, differences in DNA binding and compaction owing to variation in the cationic side chain were modest, with the rank order being arginyl > lysyl approximate to ornithyl. Incorporation of tryptophans into the DNA-binding moiety had no major effect on apparent binding affinity but clearly reduced the DNA-compacting potency of the peptides. Compared with polylysine, the peptides and their DNA complexes are weak activators of the complement system. Complement activation by an octaarginyl peptide was stronger than that induced by an octalysyl peptide. The microparticulate peptide-DNA complexes are suitable for receptor-mediated gene delivery as evidenced by transferrinfection of K562 cells in the presence of chloroquine. The results obtained in gene delivery in vitro suggest that a minimum chain length of six to eight cationic amino acids is required to compact DNA into structures active in receptor-mediated gene delivery.