The role of the acidic fragment (Asp-Glu-Glu) in delicious peptides was investigated in detail by using the Na+ or K+ salts of acidic oligopeptides so that amount of Na+ or K+ intake of peptides composed of acidic amino acids could be varied by changing their sequences. The taste of these peptides was confirmed to vary with Na+ or K+ intake. Additionally, in order to study the role of basic (Lys-Gly) and acidic (Asp-Glu-Glu) fragments in delicious peptides for producing the taste, five delicious peptide analogs, Ser-Leu-Ala-Lys-Gly-Asp-Glu-Glu, Ser-Leu-Ala-Asp-Glu-Glu-Lys-Gly, Lys-Gly-Ser-Leu-Ala-Asp-Glu-Glu, Lys-Gly-Asp-Glu-Glu, and Glu-Glu-Asp-Gly-Lys, were synthesized. The intensity of the umami and/or salty taste of these peptides and their Na salts was almost the same, despite their chemical structures being different. These results indicate that the acidic fragment as well as the basic fragment plays an important role in the taste production and intensity of delicious peptides, and that an umami or salty taste can be produced by the localization of the cation of the basic fragment and the anion of the acidic fragment.

中文翻译：

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碱性和酸性片段在美味肽（Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala）中的作用以及钠和钾盐在酸性寡肽中的味觉行为。

通过使用酸性寡肽的Na +或K +盐详细研究了酸性片段（Asp-Glu-Glu）在美味肽中的作用，从而可以通过改变氨基酸来改变由酸性氨基酸组成的肽的Na +或K +摄入量他们的顺序。这些肽的味道被证实随Na +或K +摄入量而变化。此外，为了研究碱性（Lys-Gly）和酸性（Asp-Glu-Glu）片段在美味肽中产生味道的作用，提供了五个美味的肽类似物，Ser-Leu-Ala-Lys-Gly-Asp- Glu-Glu，Ser-Leu-Ala-Asp-Glu-Glu-Lys-Gly，Lys-Gly-Ser-Leu-Ala-Asp-Glu-Glu，Lys-Gly-Asp-Glu-Glu和Glu-Glu合成了-Asp-Gly-Lys。这些肽及其钠盐的鲜味强度和/或咸味几乎相同，尽管它们的化学结构不同。