SIGNIFICANCE OF FOLATE-BINDING PROTEINS IN HUMAN MILK

这项提案将集中在颗粒物和 母乳中可溶性叶酸结合蛋白的鉴定(1)影响因素 参与确定牛奶中它们的数量和质量含量， 以及(2)这些叶酸结合蛋白在摄取中的功能作用 肠道中的叶酸。 颗粒状叶酸结合蛋白生物合成的研究 关于多肽骨架的加工、糖基化和 可能与膜插入有直接关系的酰化反应，叶酸 结合能力和可能转化为可溶性叶酸结合 蛋白质将在培养的乳腺细胞中进行研究。的影响 叶酸缺乏会对这些叶酸结合蛋白的分泌产生影响 在哺乳期大鼠身上进行了研究。 母乳、唾液、胃、 胰腺和肠道分泌物的结构完整性和配基 这些蛋白质的结合能力及其在叶酸吸收中的作用 将在大鼠肠道细胞和刷状边缘小泡中发现。在……里面 此外，自发结合的可能性，脂类相互作用， 并通过这些人乳叶酸结合到膜组件上 蛋白质将在体外进行研究。最后，这些蛋白质在 叶酸在体内的吸收将在大鼠模型中进行测试，这将 接近模拟食物对叶酸的吸收。这些研究可能会允许 全面认识叶酸结合蛋白的意义 母乳的含量及其在叶酸吸收中的作用。

This proposal will focus on two major aspects of the particulate and soluble folate binding proteins of human milk to identify (1) the factors involved in determining their quantitative and qualitative content in milk, and (2) the functional role of these folate binding proteins in the uptake of folates in the intestine. Studies on the biosynthesis of particulate folate binding proteins with respect to processing of the polypeptide backbone, glycosylation and acylation that may have a direct bearing on the membrane insertion, folate binding capacity and possible conversion to the soluble folate binding protein will be investigated in cultured mammary cells. The effect of folate deficiency on the secretion of these folate binding proteins will be investigated in lactating rats. The influence of various components of human milk, saliva, gastric, pancreatic and intestinal secretions on the structural integrity and ligand binding capacity of these proteins and their role in the uptake of folates will be identified in rat intestinal cells and brush border vesicles. In addition, the possibility of spontaneous incorporation, lipid interaction, and binding to membrane components by these human milk folate binding proteins will be studied in vitro. Finally, the role of these proteins in absorption of folates in vivo will be tested in a rat model which will closely simulates food folate absorption. These studies may allow for a comprehensive understanding of the significance of folate binding proteins of human milk and their role in the absorption of folates.