Livagen 多肽

H-KEDA-OH

H-Lys-Glu-Asp-Ala-OH

4

96.9

C₁₈H₃₁N₅O₉

461.46

固相合成

Livagen is a tetrapeptide bioregulator with the sequence Lys-Glu-Asp-Ala. The peptide has shown high biological activity, particularly in experiments with rat liver cells. When exposed to nanomolar concentrations of Livagen, the rate of protein synthesis in hepatocyte cultures from older animals increased significantly, almost reaching the levels characteristic of young rat liver cells. Additionally, Livagen has been found to restore the intracellular circadian rhythm of biosynthesis that is often disrupted by aging.
Livagen's biological activity is of interest due to its potential role in the endogenous opioid system (EOS), which is involved in various physiological functions, including pain sensitivity, emotional reactions, learning capacity, memory, hormone secretion, and the regulation of several body systems such as respiratory, cardiovascular, digestive, and immune systems, as well as thermoregulation. In extreme cases, the EOS can mediate an increase in stress tolerance, preventing the transformation of an acute stress syndrome from a stage of adaptation to a stage of pathogenesis.
The study of Livagen's effects on the EOS focused on its ability to change the activity of enkephalin-degrading enzymes in human serum and to interact with μ- and δ-opioid receptors in the membrane fraction from rat brain. The research found that Livagen inhibits enkephalin-degrading enzymes in human serum more effectively than some well-known peptidase inhibitors, with an IC50 of 20 µM. However, it did not interact with μ- and δ-opioid receptors from the rat brain. This suggests that Livagen's mechanism of action is not through direct interaction with opioid receptors but possibly through the inhibition of enzymes that degrade endogenous opioids, which could make it a promising candidate for treating stress-induced and psychosomatic disorders.

一般情况下， Livagen 多肽 粉末应该保存在-20甚至-70摄氏度. Livagen 多肽 溶解后应该-70摄氏度分装保存，避免反复冻融. 了解更多细节，请查阅手册:多肽溶解及保存指南

• Kost NV, Sokolov OIu, Gabaeva MV, Zolotarev IuA, Malinin VV, Khavinson VKh. Vliianie novykh peptidnykh bioreguliatorov livagena i épitalona na énkefalindegradiruiushchie fermenty syvorotki krovi cheloveka [Effect of new peptide bioregulators livagen and epitalon on enkephalin-degrading enzymes in human serum]. Izv Akad Nauk Ser Biol. 2003 Jul-Aug;(4):427-9. Russian. PMID: 12942748.

三氟乙酸（TFA）是一种强酸，常用于从固相树脂中裂解合成的多肽，也可用于提高多肽纯化步骤中的HPLC性能。默认情况下，定制的多肽是以冻干的TFA盐的形式交付的，其中TFA的含量可能高达10-45%。

定制多肽中的TFA可能会导致后续检测数据出现无法解释的差异。例如，nM浓度的TFA已被证明会干扰细胞实验，在某些情况下会抑制细胞增殖，而在其他情况下会增加细胞活力。

TFA去除服务推荐用于:

• 将用于细胞试验的多肽
• 将被用作原料药或制成品的多肽
• 含有大量碱性残基的亲水多肽

干品多肽的重量中不仅仅包含多肽，还包含有一些非肽的组份，如水、被吸收的溶剂、配位离子和盐等。肽的净含量是指肽在其中的重量百分比，这个百分比的数值范围很大，可能从50%到90%，取决于纯度、序列以及合成和纯化的方法，不要将肽的净含量和肽的纯度混为一谈，他们是两个完全不同的概念。纯度通常是通过HPLC测定的。纯度定义的是多肽样品中含正确序列的组分的百分比，而肽的净含量是指样品中肽类物质相对于总物质所占的百分比，肽的净含量通常是氨基酸组分分析或紫外分光法测定的，这个信息主要是在一些对肽的浓度很敏感的实验中，对计算肽的浓度是很重要的。