Hybrid Phospholipid-Phosphoinositides

描述（由申请人提供）：结合蛋白和脂质代谢酶的磷酸肌醇识别涉及与头部基团和二酰基甘油骨架的特异性相互作用，其在蛋白质与蛋白质之间存在显著差异。当荧光探针被引入肌醇头基时，结合和代谢被严重减弱或完全消除。当荧光探针被引入到酰基中时，许多所得衍生物不能显示足够的Km和Vmax值作为脂质激酶和磷酸酶的底物以及与同源PIP结合蛋白的结合。最近，Echelon Biosciences开发了一种新的方法来制造基于四碳苏糖醇骨架的磷脂-磷酸肌醇杂合体。这些被称为Pea-PIPs TM的新材料具有磷脂酰乙醇胺头基，其允许生化或化学探针连接在与磷酸肌醇头基和两个酰基链空间正交的位置。在第一阶段的资助中，我们将首先合成所有八个Pea-PIPns TM的完整曲目。其次，我们将制备两种具有四种不同亲水性连接臂的Pea-PIP TM，以优化探针-头基团距离。第三，我们将建立使用Pea-PIP TM作为脂质激酶、脂质磷酸酶和脂质结合蛋白的体外底物的可行性。

DESCRIPTION (provided by applicant): Phosphoinositide recognition by binding proteins and lipid-metabolizing enzymes involves specific interactions with the head group and diacylglycerol backbone, which vary significantly from protein to protein. When a fluorescent probe is introduced into the inositol head group, binding and metabolism are severely attenuated or abrogated entirely. When a fluorescent probe is introduced into the acyl groups, many of the resulting derivatives fail to show adequate Km and Vmax values as substrates for lipid kinases and phosphatases as well as binding to cognate PIP-binding proteins. Recently, Echelon Biosciences has developed a new approach to make phospholipid-phophoinositide hybrids based on a four-carbon threitol backbone. These new materials, known as Pea-PIPs TM, have a phosphatidylethanolamine head group that permits biochemical or chemical probes to be attached in a position spatially orthogonal to the phosphoinositide head group and the two acyl chains. In this Phase i grant, we will first synthesize a full repertoire of all eight Pea-PIPns TM. Second, we will prepare two Pea-PIPs TM with four different hydrophilic linker arms to optimize probe-head group distances. Third, we will establish the feasibility of using Pea- PIPs TM as in vitro substrates for lipid kinases, lipid phosphatases, and lipid binding proteins.