Development of Polymerized Liposomes for Protein Recognition

智力价值：建议开发旨在识别特定蛋白质的脂质体，其表面拓扑结构已印在脂质体的表面上。 本研究的目标蛋白是基质金属蛋白酶-9，它参与许多生理和病理过程。 将使用各种脂质（阳离子、中性和阴离子）构建脂质体，以便允许调节脂质体，使其凝胶转变温度高于靶蛋白经历热变性的温度。 具有适合光聚合的功能的脂质将包含在脂质混合物中。 一些脂质还具有与酶特异性结合的头基，从而使蛋白质相对于脂质体表面独特地定向。 在脂质体凝胶转变温度和蛋白质变性温度之间的中间温度下孵育复合物期间，膜的流动性将允许脂质体将其表面适应蛋白质表面，并形成用于随后与该蛋白质结合的互补模板。 然后冷却至脂质体凝胶转变以下并进行脂质体膜的光聚合，然后锁定模板。 初步工作表明，相对于未模板化的脂质体，酶对模板化脂质体的亲和力增强了1-2个数量级。 该工作将按如下方式进行：（i）合成结构多样的可聚合脂质，以配制用于同工酶选择性检测和抑制基质金属蛋白酶-9（MMP-9）的脂质体，（ii）配制具有不同类型头部基团的聚合脂质体，作为MMP同工酶的高度特异性多管脚抑制剂，（iii）使用螯合的Eu（III）和Tb（III）开发基于荧光的传感器，用于MMP-9 的同工酶选择性检测，(iv) 确定脂质体辅助检测和抑制 MMP-9 的机制更广泛的影响：所提出的工作为分子印迹开辟了一条新途径，特别是在蛋白质识别和“人工抗体”制备领域。 可以想象其应用在基于脂质体的生物战剂诊断工具、植物和动物病原体的检测以及预防和治疗剂的开发中。 PI 将支持两名在实验室工作的美国原住民本科生。 两者都将在其实验室接待高中生和公立学校教师，参加 NDSU 资助的夏季研究项目。

INTELLECTUAL MERIT: It is proposed to develop liposomes that have been designed to recognize specific proteins, the surface topology of which has been imprinted on the surface of the liposomes. The targeted protein for this study is matrix metalloproteinase-9, which is involved in a number of physiological and pathological processes. Liposomes will be constructed using a variety of lipids, cationic, neutral, and anionic, in order to permit tuning of the liposome so that its gel transition temperature lies above the temperature at which the target protein undergoes thermal denaturation. Lipids possessing functionality suitable for photopolymerization will be included in the lipid mixture. Some of the lipids will also have head groups that bind specifically to the enzyme so as to orient the protein uniquely with respect to the liposome surface. During incubation of the complex at a temperature intermediate between the gel transition of the liposome and the denaturation temperature of the protein, the fluidity of the membrane will permit the liposome to accommodate its surface to the surface of the protein and form a complementary template for later binding of that protein. Cooling below the gel transition of the liposome and photopolymerization of the liposome membrane then locks in the template. Preliminary work shows that the affinity of the enzyme for the templated liposome is enhanced by one - two orders of magnitude relative to the untemplated liposome. The work will proceed as follows: (i) synthesize structurally diverse, polymerizable lipids to formulate liposomes for isozyme-selective detection and inhibition of matrix metalloproteinase-9 (MMP-9), (ii) formulate polymerized liposomes with different types of head groups to serve as highly specific multi-prong inhibitors for MMP isozymes, (iii) develop fluorescence based sensors using chelated Eu(III) and Tb(III) for the isozyme-selective detection of MMP-9, (iv) determine the mechanisms of the liposome assisted detection and inhibition of MMP-9BROADER IMPACTS: The proposed work opens a new avenue to molecular imprinting, especially in the area of protein recognition and "artificial antibody" preparation. Applications can be imagined in liposome-based diagnostic tools for biological warfare agents, detection of plant and animal pathogens, and development of prophylactic and therapeutic agents. The PIs will support two Native American undergraduates working in the lab. Both will host high school students and public school teachers in their laboratories in NDSU-sponsored summer research programs.