Oral Complex Carbohydrate Sensing

摘要 碳水化合物在人类饮食中起着重要作用，其摄入量直接影响 人类健康。为了控制碳水化合物的摄入，了解味觉系统是如何 对他们做出回应。最近，我们报道了人类可以品尝到以葡萄糖为基础的寡糖，而且他们的 检测不依赖于已知的甜味受体。在这些发现的基础上，这项提议寻求 确定人类可以品尝的低聚糖的范围，并进一步确定其结构 低聚糖的特性，使其能够被人类感知。这个项目有两个主要部分 假设：(1)人类可以品尝到广泛的寡糖，以及(2)味觉的检测取决于 低聚糖的分子结构与单体构筑块、链类型的关系 糖苷键的长度、位置和数量，以及末端残基。这两个假设将得到检验。 通过使用一系列天然存在的、定义明确的低聚糖和精选的衍生物。两种功能 将考虑不同类别的低聚糖：(A)淀粉衍生的可消化低聚糖 饮食能量的主要来源和(B)非淀粉低聚糖，不被人类消化，但 被认为对健康有益的(例如，益生素)。认识到商业上可用的低聚糖是 对于不同形态的“鸡尾酒”，我们建议提纯或分离目标低聚糖。 因此，这一项目的另一个重要成果将是可供公众使用的 用于人体试验的定义明确的、天然的和衍生的低聚糖的制备。这些化合物 应该被证明是未来以分子表征为目的的有价值的候选配体 寡糖受体(S)。

SUMMARY Carbohydrates play a significant role in the human diet and the extent of their consumption directly impacts human health. In order to control carbohydrate consumption, it is critical to understand how the gustatory system responds to them. Recently, we reported that humans can taste glucose-based oligosaccharides and that their detection is independent of the known sweet receptor. Building upon these findings, this proposal seeks to establish the range of oligosaccharides that humans can taste and further to determine the structural characteristics of oligosaccharides that enable their perception by humans. This project has two overarching hypotheses: (1) that humans can taste a wide range of oligosaccharides, and (2) that taste detection depends on the molecular structures of oligosaccharides with respect to the types of monomer building blocks, chain length, position and number of glycosidic linkages, and terminal residues. These two hypotheses will be tested by using a range of naturally existing, well-defined oligosaccharides and selected derivatives. Two functionally different groups of oligosaccharides will be considered: (a) starch-derived digestible oligosaccharides that are primary sources of dietary energy and (b) non-starch oligosaccharides that are not digested by humans but are considered beneficial to health (e.g., prebiotics). Recognizing that commercially available oligosaccharides are heterogeneous “cocktails” with undefined profiles, we propose to purify or isolate target oligosaccharides. Accordingly, an important additional outcome of this project will be publically available protocols for the preparation of well-defined, natural and derivatized oligosaccharides for human testing. These compounds should prove to be valuable candidate ligands for future studies aimed at the molecular characterization of oligosaccharide receptor(s).