AK15 多肽

H-AKKKLSRWWLRWWVK-OH

H-Ala-Lys-Lys-Lys-Leu-Ser-Arg-Trp-Trp-Leu-Arg-Trp-Trp-Val-Lys-OH

15

95.2

C₁₀₃H₁₅₅N₂₉O₁₇

2071.51

固相合成

AK15 is a small mycobacteriophage-derived peptide. AK15 adopted cationic amphiphilic α-helical structure. Both AK15 and AK15–6 directly inhibited M. tb by trehalose 6, 6’-dimycolate (TDM)–binding and membrane–disruption. They both exhibited bactericidal activity, cell selectivity, and synergistic effects with rifampicin, and none induced drug resistance to M. tb. They efficiently attenuated mycobacterial load in the lung of M. tb–infected mice. AK15 and its isomer AK15–6 showed apparent affinity to mycobacterial cord factor. The pre–incubation of AK15 or AK15–6 with TDM blocked the anti–mycobacterial activity of the peptides. AK15 and its isomer AK15–6 impaired the surface morphology of M. tb. AK15 and its isomer AK15–6 increased the passive diffusion of the fluorescent dye into M. tb. AK15 and its isomer AK15–6 induced the leakage of intracellular ATP from M. tb. AK15 and its isomer AK15–6 showed cell selectivity to M. tb. Positively charged residues, aromatic residues and α–helix constitute the key structural requirements of the peptides. AK15 and its isomer AK15–6 showed none induced drug resistance to M. tb. AK15 and its isomer AK15–6 generated synergistic effects with rifampincin against M. tb. AK15 and its isomer AK15–6 exhibited thermal stability and low toxicity to mice. AK15 and its isomer AK15–6 restrained TDM-stimulated inflammatory signaling activation and inflammatory cytokine production in murine macrophages. AK15 and its isomer AK15–6 efficiently protected mice from M. tb infection. AK15 and its isomer AK15–6 enhanced modest basal immune responses in BMDMs and mice.

一般情况下， AK15 多肽 粉末应该保存在-20甚至-70摄氏度. AK15 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

• Yang Y, Liu Z, He X, et al. A small mycobacteriophage-derived peptide and its improved isomer restrict mycobacterial infection via dual mycobactericidal-immunoregulatory activities. J Biol Chem. 2019;294(19):7615-7631

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。