FATTY ACID TRANSPORT IN THE INTESTINE

说明：本提案的具体目标是：1）确定 消化脂质产物从胶束转移的速率和机制， 囊泡和餐后消化阶段的混合群体。 这些 研究将使用最近开发的实验系统， 主要研究者（P.I.）来定量检测 管腔脂肪酸（FA）和单甘酯（MG）转移的机制; 2） 确定两种肠细胞FABP的分子机制， 调节FA和MG向膜的转移。 私家侦探最近 显示IFABP通过与FA的碰撞相互作用将FA转移到膜上， 膜。 这些研究将确定结构域 负责这些相互作用的定点诱变组合 蛋白质-膜相互作用的生物化学和生物物理分析。 此外，还研究了MG从LFABP向膜转移的速率和机理 将被确定，因为它最近已被证明，MG是一个 LFABP的特异性配体;和3）研究IFABP和LFABP在 细胞FA和MG摄取和转运。 私家侦探之前已经表明， Caco-2细胞，不像实际的肠上皮细胞，表达LFABP，但不表达IFABP。 在 这些研究私家侦探将使用Caco-2细胞，不像真正的肠细胞， 只表达LFABP而不表达IFABP。 在这些研究中，P.I.将使用 用野生型或特异性突变IFABP转染的Caco-2细胞， 检查L-和IFABP对细胞内运输的影响， FA和MG，以及肠上皮细胞脂质代谢。 长期目标是 研究的目的是通过调节 具体的运输过程。

DESCRIPTION: The specific aims of this proposal are: 1) To determine the rates and mechanisms of transfer of digestive lipid products from micelles, vesicles, and mixed populations of postprandial digestive phases. These studies will use a recently developed experimental system which allows the principal investigator (P.I.) to quantitatively examine the kinetic mechanisms of luminal fatty acid (FA) and monoglyceride (MG) transfer; 2) To determine the molecular mechanisms by which the two enterocyte FABP's modulate the transfer of FA and MG to membranes. The P.I. has recently shown that IFABP transfers FA to membranes by collisional interactions with the membrane. These studies will determine the structural domains responsible for these interactions using site-directed mutagenesis combined with biochemical and biophysical analysis of protein-membrane interactions. In addition, the rate and mechanism of MG transfer from LFABP to membranes will be determined, as it has been recently demonstrated that MG is a specific ligand for LFABP; and 3) To examine the role of IFABP and LFABP in cellular FA and MG uptake and transport. The P.I. has shown previously that Caco-2 cells, unlike actual enterocytes, express LFABP but not IFABP. In these studies, the P.I. will use Caco-2 cells, unlike actual enterocytes, express only LFABP but not IFABP. In these studies, the P.I. will use Caco-2 cells transfected with wild type or specific mutant IFABP's to examine the effects of L- and IFABP on both the intracellular trafficking of FA and MG, and on enterocyte lipid metabolism. The long term goal of this research is to enable the control of lipid assimilation by modulation of specific transport processes.