Functionalization of cobalt porphyrin-phospholipid bilayers with his-tagged ligands and antigens.
Functionalization of cobalt porphyrin-phospholipid bilayers with his-tagged ligands and antigens.
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将多肽连接到脂质双层的方法通常是间接的、无效的，并且可以代表形成官能化的基于脂质的材料的实质性瓶颈。虽然聚组氨酸标签（his标签）已经在其简单性和有效性结合固定化金属的变革，这种方法的成功应用一直具有挑战性的生理设置。在这里，我们表明，脂质双层含有卟啉磷脂，是与钴螯合，而不是其他金属，可以有效地捕获组氨酸标记的蛋白质和肽。的结合遵循Co（II）到Co（III）的过渡，并发生在受保护的疏水性双层内，导致在血清中基本上不可逆的附着或竞争性咪唑的百万倍过量。使用这种方法，我们将归巢肽锚定到预先形成的和负载货物的脂质体的双层中，以在不破坏双层完整性的情况下实现肿瘤靶向。作为进一步的证明，将合成的HIV衍生的蛋白片段结合到免疫原性脂质体上，用于产生针对其他非抗原性肽的有效抗体。
Methods to attach polypeptides to lipid bilayers are often indirect, ineffective and can represent a substantial bottleneck in the formation of functionalized lipid-based materials. Although the polyhistidine tag (his-tag) has been transformative in its simplicity and efficacy in binding to immobilized metals, the successful application of this approach has been challenging in physiological settings. Here we show that lipid bilayers containing porphyin-phospholipid that is chelated with cobalt, but not other metals, can effectively capture his-tagged proteins and peptides. The binding follows a Co(II) to Co(III) transition and occurs within the sheltered hydrophobic bilayer, resulting in essentially irreversible attachment in serum or in million-fold excess of competing imidazole. Using this approach we anchored homing peptides into the bilayer of preformed and cargo-loaded liposomes to enable tumour-targeting without disrupting the bilayer integrity. As a further demonstration, a synthetic HIV-derived protein fragment was bound to immunogenic liposomes for potent antibody generation for an otherwise non-antigenic peptide.