FLUORESCENCE STUDIES OF FATTY ACID BINDING PROTEINS

脂肪酸结合蛋白（FABP）是一类小分子胞浆蛋白 在许多哺乳动物组织和细胞类型中丰富，包括 肠、肝、心脏、髓磷脂和脂肪细胞。 一般认为 FABPs作为游离脂肪酸（FFA）的转运体发挥重要作用 或作为FFA水平的细胞内缓冲液。 然而，它们的确切作用尚不清楚， 来自不同组织的FABPs之间的差异（只有24%的FABPs被识别出来）。 有些情况下）表明，可能存在不同的约束力和使用 不同组织间FFA类型不同。 本研究的长期目标是（1）了解 FABPs的生物学功能，特别是生物化学和 组织特异性FABP的生物学意义;（2）在氨基上构建 酸水平一个清晰的分子图像描述如何结合亲和力和 特异性被构建到FABP中;以及（3）设计具有新的 可用于构建特异于以下的探针的结合性质： 生物学上重要的FFA类型。 这些探测器将来可能会 重要的诊断应用。 具体来说，我们将使用荧光光谱法来监测 FFA与FABP的结合。 这项技术将使我们能够测量 精确地计算了这种结合的热力学和动力学性质， 一组不同的FABP和FFA的反应。 这类研究有 由于缺乏合适的测定，过去不可能 系统 我们计划检测5种组织中FABP的结合情况 上述（在某些情况下来自人类和啮齿动物）的FFA 不同的长度和不饱和度。 这些研究将提供 FABPs生物学作用的重要线索。 然后我们计划解剖 通过进行相同的结合研究进一步研究FABP-FFA相互作用 与专门设计的突变重组FABP和使用我们的 积累的实验结果与计算机辅助分子 建模方法来构建FABP-FFA复合物的相干图像。 最后，我们计划利用这些研究的结果来构建 具有新的FFA结合亲和力和特异性的重组FABP。

Fatty acid binding proteins (FABP) are a family of small cytosolic proteins that are abundant in many mammalian tissues and cell-types, including intestine, liver, heart, myelin, and adipocytes. It is generally believed that FABPs play important roles as transporters of free fatty acids (FFA) among intracellular organelles or as intracellular buffers of FFA levels. Their precise role(s) are unknown, however, and the substantial sequence divergence among FABPs from different tissues (as little as 24% identify in some cases) suggests that there may be differential binding and usage of different FFA types among different tissues. The long-term goals of the present studies are (1) to understand the biological function(s) of FABPs, and in particular, the biochemical and biological significance of tissue-specific FABPs; (2) to build at the amino acid level a clear molecular picture describing how binding affinity and specificity are built into FABPs; and (3) to design FABPs with novel binding properties that can be used to construct probes specific for biologically important FFA types. These probes may in the future have important diagnostic applications. Specifically, we will use a fluorescent spectroscopic method to monitor the binding of FFA to FABP. This technology will allow us to measure accurately the thermodynamic and kinetic properties of this binding reaction for a set of distinct FABPs and FFAs. Studies of this kind have not been possible in the past due to the absence of a suitable assay system. We plan to examine the binding of FABPs from the 5 tissues mentioned above (in some cases from both humans and rodents) to FFAs of varying lengths and levels of unsaturation. These studies should provide important clues to the biological role of FABPs. We then plan to dissect further the FABP-FFA interaction by carrying out the same binding studies with specifically designed mutant recombinant FABPs and to use our accumulated experimental results together with computer-aided molecular modeling methods to construct a coherent picture of the FABP-FFA complex. Finally, we plan to use the results of these studies to construct recombinant FABPs with novel FFA binding affinities and specificities.