Septide 多肽

Pyr-FFPLM-NH2

Pyr-Phe-Phe-Pro-Leu-Met-NH2

5

95.82

C₃₉H₅₃N₇O₇S

763.94

79775-19-2

119137

固相合成

Septide is a synthetic peptide with the amino acid sequence [pGlu⁶, Pro⁹]Substance P^9-11. It is known to have tachykinin-like actions despite its apparent lack of binding to any known tachykinin receptor initially. However, later studies have shown that Septide binds to the NK-1 receptor with high affinity.
Binding Affinity to NK-1 Receptor: In homologous binding assays, Septide has a Kd value of 0.55 ± 0.03 nM, indicating high-affinity binding to the NK-1 receptor. In competition against radiolabeled NKA, Septide also appears as a high-affinity ligand on the NK-1 receptor, with a Ki value of 1.90 ± 0.35 nM. Similarly, NKA can compete with high affinity for Septide binding on the NK-1 receptor, with a Ki value of 0.21 ± 0.01 nM.
Role in Tachykinin Receptor Actions: The finding that Septide binds with high affinity to the NK-1 receptor suggests that the NK-1 receptor may function as a general tachykinin receptor, binding subnanomolar concentrations of not only the naturally occurring neuropeptides substance P (SP) and neurokinin A (NKA), but also the synthetic peptide Septide. This observation challenges the previous notion that a special "septide receptor" or an extra NKA binding receptor might exist.
Overall, Septide is an important peptide in the study of tachykinin receptors and their functions, providing insights into the complex interactions between peptides and receptors in the nervous system.

一般情况下， Septide 多肽 粉末应该保存在-20甚至-70摄氏度. Septide 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

• Hastrup H, Schwartz TW. Septide and neurokinin A are high-affinity ligands on the NK-1 receptor: evidence from homologous versus heterologous binding analysis. FEBS Lett. 1996 Dec 16;399(3):264-6. doi: 10.1016/s0014-5793(96)01337-3. PMID: 8985159.

三氟乙酸（Trifluoroacetic acid，简称 TFA）是高效液相色谱（简称 HPLC）纯化过程中常用的反离子。TFA 的存在可能会对肽的净重量、外观及溶解度产生影响，具体如下：

对净重量的影响：TFA 盐会增加产物的总质量。在大多数情况下，肽的含量占总重量的 80% 以上，剩余部分则为 TFA。

对溶解度的影响：TFA 盐通常能提高肽在水溶液中的溶解度。

在生物检测中的影响：对于大多数标准的体外检测，残留的 TFA 水平一般不会造成干扰。但需注意，在高灵敏度的细胞研究或生化研究中，需关注其存在可能带来的影响。

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。