NOVEL METHODS FOR PREPARING SYNTHETIC ANTIBODIES

该提案旨在继续使用聚合脂质体制造稳健的，选择性的蛋白质化学受体的工作。 在本项目期间，该方法将发展到高度选择性。 在优化研究之后，将测试脂质体用于蛋白质分离、生物成像、靶向递送和生物传感器的制造。所提出的用于产生蛋白质的稳定化学受体的方法依赖于在脂质体上产生金属离子、离子对和氢键合位点的三维图案，其与所选蛋白质所呈现的图案互补。将用离子脂质、脂质（季铵盐）、金属螯合脂质和在其头部基团上具有伯胺部分的脂质制备混合的可聚合脂质体。可聚合的二酰基磷酸胆碱（两性离子）将用作这些脂质体的主要成分。在制造之后，这些脂质体（处于未聚合状态）将被允许与所选择的蛋白质相互作用。 由于脂质的横向扩散流动性，脂质体表面上的金属离子将与蛋白质的表面暴露组氨酸的图案互补地取向。 脂质体上的季铵头基将通过蛋白质表面上的酸性氨基酸侧链（Asp、Glu）定位。能够形成氢键的蛋白质的氨基酸侧链（例如，Ser、Thr、Lys、Asn、Gln和Arg）将与脂质体上的伯胺部分相互作用。 该平衡步骤的结果是在脂质体表面上产生金属离子、电荷和氢键合位点的图案，其与蛋白质表现出的表面图案互补。然后，这些图案化的脂质体将被光聚合以捕获和锁定由平衡步骤产生的表面图案。 聚合的脂质体将通过在三维中的大量同时和互补的相互作用“识别”所选择的蛋白质;因此脂质体和蛋白质之间的结合将是强的和选择性的。

This proposal aims to continue the work on the fabrication of robust, selective, chemical receptors for proteins using polymerized liposomes. During this project period, the method will be developed to a high degree of selectivity. After the optimization studies, the liposomes will be tested for separation of proteins, biological imaging, targeted delivery and the fabrication of biosensors. The proposed method for creating stable chemical receptors for proteins relies on creating a three dimensional pattern of metal ions, ion pairs and hydrogen bonding sites on a liposome, complementary to the pattern exhibited by the protein of choice. Mixed polymerizable liposomes will be prepared with ionic lipids, lipids (quaternary ammonium salts), metal-chelating lipids and lipids with primary amine moiety on their head-groups. Polymerizable diacyl phosphocholine (zwitter ionic) will be used as the major constituent of these liposomes. After fabrication, these liposomes (in the unpolymerized state) will be allowed to interact with the selected protein. Due to the lateral diffusional mobility of the lipids, the metal ions on the liposome surface will orient complementary to the pattern of surface-exposed histidines of the protein. The quaternary ammonium headgroups on the liposomes will be positioned by the acidic amino acid side chains (Asp, Glu) on the protein surface. Amino acid side chains of the protein capable of forming hydrogen bonds (e.g., Ser, Thr, Lys, Asn, Gln and Arg) will interact with the primary amine moieties on the liposome. The result of this equilbration step is the creation of a pattern of metal ions, charges and hydrogen bonding sites on the liposome surface complementary to the surface pattern exhibited by the protein. These patterned liposomes will then be photo-polymerized to capture and lock the surface pattern created by the equilibration step. The polymerized liposomes will "recognize" the selected protein by a wide array of simultaneous and complementary interactions in three dimensions; hence binding between the liposomes and the protein will be strong and selective.