Dermaseptin-S8 多肽

H-ALWKTMLKKLGTVALHAGKAALGAAADTISQ-NH2

H-Ala-Leu-Trp-Lys-Thr-Met-Leu-Lys-Lys-Leu-Gly-Thr-Val-Ala-Leu-His-Ala-Gly-Lys-Ala-Ala-Leu-Gly-Ala-Ala-Ala-Asp-Thr-Ile-Ser-Gln-NH2

31

95.2

C₁₄₁H₂₄₀N₄₀O₃₈S

3135.71

固相合成

Dermaseptin sVIII has only one site of amino acid substitution when compared with dermaseptin sI. Unlike dermaseptin s1, mature dermaseptin sVI–sVIII peptides lacked the C-terminal tripeptide (-GE/AQ) of the precursor openreading frame deduced from their respective cDNAs. MS/ MS fragmentation of each peptide using a QTOF-Ultima instrument (Micromass, UK), established that each was C terminally amidated with either an isoleucine amide (sVI) or a glutamine amide (sVII–sVIII). The defensive skin secretions of frogs are known to contain a plethora of biologically active peptides, some of which share common primary structural features with endogenous vertebrate regulatory peptides and others that appear to have no obvious structural counterparts in higher vertebrates. The dermaseptins constitute a group of peptides that fall into the latter category displaying broad spectrum antimicrobial activity against both bacteria and fungi The role of this peptide family, typically consisting of 27–34 amino acid residues, is thought to be in defending the naked moist skin of the frogs against environmental or pathogenic microbial invasion. One must bear in mind that the integument of the amphibian plays many important physiological roles including respiration and osmoregulation—fundamental processes that could impinge upon the well-being of the animal if impaired by microbial colonisation. In fact, dermaseptins were the first vertebrate peptides to exhibit lethal effects against the filamentous fungi responsible for severe opportunistic infections accompanying immunodeficiency syndrome and the use of immunosuppressive agents.

一般情况下， Dermaseptin-S8 多肽 粉末应该保存在-20甚至-70摄氏度. Dermaseptin-S8 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

• Chen T, Tang L, Shaw C. Identification of three novel Phyllomedusa sauvagei dermaseptins (sVI-sVIII) by cloning from a skin secretion-derived cDNA library. Regul Pept. 2003;116(1-3):139-46

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。