Friedman Mendel, Levin Carol E
United States Department of Agriculture, Western Regional Research Center, Agricultural Research Service, Albany, CA, USA.
Methods Mol Biol. 2012;794:337-53. doi: 10.1007/978-1-61779-331-8_23.
This paper describes a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as L-lysine (L-Lys), L-methionine (L-Met), L -phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential amino acids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid. Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino acid for such determinations may be preferable to protein-based diets.
本文描述了一种通过在喂食合成全氨基酸饮食的小鼠中进行生长试验来测定D-氨基酸、D-肽和氨基酸衍生物营养价值的方法。进行了大量实验，其中用等摩尔当量的测试化合物替代一种营养必需氨基酸，如L-赖氨酸（L-Lys）、L-甲硫氨酸（L-Met）、L-苯丙氨酸（L-Phe）和L-色氨酸（L-Trp），以及半必需氨基酸L-半胱氨酸（L-Cys）和L-酪氨酸（L-Tyr）。结果表明，测试物质的生物利用率存在广泛差异。该方法通常适用于测定任何氨基酸衍生物作为相应L-氨基酸潜在营养来源的生物利用率和安全性。由于生物体被迫使用D-氨基酸或氨基酸衍生物作为被替代的必需或半必需氨基酸的唯一来源，并且由于游离氨基酸饮食允许更好地控制成分，因此使用全氨基酸进行此类测定可能比基于蛋白质的饮食更可取。
