Hybrid Phospholipid-Phosphoinositides

说明(申请人提供)：结合蛋白和脂肪代谢酶识别磷脂酰肌醇涉及与头基和二酰甘油主链的特定相互作用，这两种作用因蛋白质而异。当将荧光探针引入肌醇头部基团时，结合和新陈代谢严重减弱或完全取消。当将荧光探针引入酰基时，所得到的许多衍生物不能显示足够的Km和Vmax作为脂蛋白和磷酸酶的底物，也不能与同源的PIP结合蛋白结合。最近，梯形生物科学公司开发了一种新的方法来制备基于四碳苏糖醇骨架的磷脂-磷脂杂化化合物。这些新材料被称为Pea-PIPs TM，具有磷脂酰乙醇胺头部基团，允许生化或化学探针附着在与磷脂酰肌醇头部基团和两个酰基链空间垂直的位置。在这个第一阶段授予，我们将首先合成一个完整的曲目所有八个豌豆-PIPns TM。其次，我们将制备两个具有四个不同亲水连接臂的Pea-PIPs TM，以优化探头基团的距离。第三，我们将确定使用Pea-PIPs TM作为脂激酶、脂磷酸酶和脂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.