NUTRITIONAL ROLE OF MANGANESE BINDING MOLECULES IN MILK

这项提案的总体目标是描述锰元素的特征 牛奶中的结合配体及其在吸收中的作用 金属。利用外在Labvel技术研究几种锰结合配体 已经在人奶、牛奶和婴儿配方奶粉中被鉴定出来 调查员。这些锰结合蛋白和低分子量 LIGHTAND将进一步提纯并使用生化方法进行表征 凝胶渗透和离子交换柱层析等技术， 圆盘和水平聚丙烯酰胺凝胶电泳法 分析和制备等电聚焦和薄层 层析法。理化性质，包括数量 金属结合部位、金属结合亲和力、氨基酸组成和 如果时间允许，多肽物种的主要序列将是 调查过了。内源性结合的异同 配体和外源标记的结合配体将通过使用 大鼠柔软剂的体内和体外标记。.的存在 成人和哺乳期肠粘膜中锰结合配体的研究 还将对大鼠和培养的皮肤成纤维细胞进行研究。他们的 性能将与牛奶金属载体的性能进行比较。这个 人乳、牛奶中矿物质的相对生物利用度 和婴儿配方奶粉，以及化学形式对 生物利用度，例如当它们以无机盐、有机形式存在时 盐或金属多肽将在三个不同的水平上进行研究， 即全动物水平采用哺乳大鼠，组织水平采用培养 大鼠肠道和细胞水平的培养皮肤成纤维细胞。 将使用放射性锰，其摄取量将通过计数来测量 乳鼠、组织或细胞的同位素含量。反应的动力学 从外源性标签奶中摄取锰的过程将在 这三个层次都是。代谢和蛋白质合成的影响 抑制剂和温度将在体外使用这两种药物进行研究 系统。这项提议的长期目标之一是理解 化学环境对痕量生物利用度的影响 矿物。从这个项目中获得的信息将有助于澄清 锰的吸收机制。这一知识将确保 生产一种更合适的乳房温和替代品，并将谨慎 婴儿的微量矿物质缺乏或毒性的发展。这个 制定的程序将有助于更有力地比较 不同的乳房温和替代品。它们还可以用来评估 牛奶中其他必需微量元素、维生素等的生物利用度。 这项研究还将提供有关成熟过程的信息。 胃肠道的。

The overall objective of this proposal is to characterize the manganese binding ligands in milk and to study their functions in absorption of this metal. Using extrinsic labvel techniques several manganese binding ligands have been identified in human milk, cow's milk and infant formula by the investigator. These manganese binding proteins and low molecular weight lighand will be further purified and characterized using biochemical techniques such as gel permeation and ion exchange column chromatography, disc and horizontal polyacrylamide gel electrophoresis with and withour SDS, analytical and preparative isoelectric focusing and thin layer chromatography. The physicobiochemical properties, including the number of metal binding sites, metal binding affinities, amino acid composition, and if time allows, the primary seqeunce of the peptidic species will be investigated. The similarity and difference between endogenous binding ligands and extrinsically labelled binding ligands will be studied by using in vivo and in vitro labelling of mild from rats. The presence of manganese binding ligands in the intestinal mucosa of adult and suckling rats and in cultured skin fibroblasts will also be investigated. their properties will be compared with those of the milk metal carriers. The relative bioavailability of the mineral from human breast milk, cow's milk and infant formula, and the effects of the chemical form on bioavailability, such as when they are present as inorganic salts, organic salts, or metallopeptides will be studied at three different levels, namely, whole animal level using suckling rats, tissue level using cultured rat intestine and cellular level using cultured skin bibroblasts. Radioactive Mn will be used, and its uptake will be measured by counting the isotopic content of the suckling rat, tissue or cells. the kinetics of the uptake process for Mn from extrinsic labelled milk will be studies at all three levels. The effects of metabolic and prtein synthesis inhibitors, and temperature will be investigated using the two in vitro systems. One of the long term objectives of this proposal is to understand the effect of chemical environment on the bioavailability of the trace minerals. The information obtained from this project will help to clarify the mechanism of absorption of manganese. This knowledge will insure the production of a more approporate substitue for breast mild and will caution the development of trace mineral deficiency or toxicity in infants. The procedures developed will be useful for more vigorous comparison among the different breast mild substitutes. They can also be used to evaluate the bioavailability of other essential trace minerals, vitamins, etc. in milk. This study will also provide information concerning the maturation process of the gastrointestinal tract.