NOVEL METHODS FOR PREPARING SYNTHETIC ANTIBODIES

这项建议旨在继续利用聚合脂质体制造强健的、选择性的蛋白质化学受体的工作。在本项目期间，该方法将向高度选择性发展。在优化研究后，脂质体将用于蛋白质分离、生物成像、靶向传递和生物传感器的制造。所提出的为蛋白质创建稳定的化学受体的方法依赖于在脂质体上创建金属离子、离子对和氢键位置的三维图案，与所选择的蛋白质所展示的图案互补。由离子脂、脂类(季铵盐)、金属络合脂类和头上带有伯胺基团的脂类制备混合可聚合脂质体。可聚合的二酰基磷胆碱(Zwitter Ion)将被用作这些脂质体的主要成分。制造完成后，这些脂质体(处于未聚合状态)将被允许与所选蛋白质相互作用。由于脂类的横向扩散迁移性，脂质体表面的金属离子将与蛋白质表面暴露的组氨酸图案方向互补。脂质体上的季铵盐头基会被蛋白质表面的酸性氨基酸侧链(天冬氨酸、谷氨酸)所定位。能够形成氢键的蛋白质的氨基酸侧链(如丝氨酸、苏氨酸、赖氨酸、天冬氨酸、谷氨酰胺和精氨酸)将与脂质体上的伯胺部分相互作用。这一平衡步骤的结果是在脂质体表面上创建了金属离子、电荷和氢键位置的图案，与蛋白质显示的表面图案互补。这些图案化的脂质体随后将被光聚合，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广泛的同时和互补的三维相互作用来“识别”选定的蛋白质；因此，脂质体和蛋白质之间的结合将是强大的和选择性的。

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.