KR-12 (human) 多肽

KRIVQRIKDFLR-NH2

H-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-NH2

12

99.81

C₇₁H₁₂₇N₂₅O₁₅

1570.93

1218951-51-9

固相合成

KR-12 peptide is derived from the human antimicrobial peptide LL-37, and corresponds to its amino acid residues 18-29. It retains the antimicrobial activity of LL-37 while showing low toxicity to human cells, making it a potential candidate for various applications, especially in cosmetics.

KR-12 peptide has a nearly perfect amphipathic α -helical structure. This unique structure endows it with strong antimicrobial properties. It can effectively inhibit the growth of a wide range of bacteria and yeast. Its minimal inhibitory concentration (MIC) values against different strains are impressively low, much lower than those of common cosmetic preservatives like methylparaben and Scutellaria baicalensis extract. When incorporated into cosmetic formulations, KR-12 peptide exhibits excellent bactericidal effects. It can kill gram - negative Escherichia coli at concentrations starting from 25 μg/mL and gram - positive Staphylococcus aureus at 100 μg/mL, while conventional preservatives show no significant bactericidal activity even at higher concentrations.

Moreover, KR-12 peptide shows very low cytotoxicity to mammalian cells. In MTT assays with RAW264.7 cells, it demonstrated negligible toxicity even at relatively high concentrations. This makes it a safe and effective alternative to traditional cosmetic preservatives, offering a new solution for ensuring the stability of cosmetic products without causing harm to the human body.

一般情况下， KR-12 (human) 多肽 粉末应该保存在-20甚至-70摄氏度. KR-12 (human) 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

• Yun, H., Min, H.J. & Lee, C.W. NMR structure and bactericidal activity of KR-12 analog derived from human LL-37 as a potential cosmetic preservative. J Anal Sci Technol 11, 14 (2020). https://doi.org/10.1186/s40543-020-00213-x
• Kamysz E, Sikorska E, Jaśkiewicz M, Bauer M, Neubauer D, Bartoszewska S, Barańska-Rybak W, Kamysz W. Lipidated Analogs of the LL-37-Derived Peptide Fragment KR12-Structural Analysis, Surface-Active Properties and Antimicrobial Activity. Int J Mol Sci. 2020 Jan 30;21(3):887. doi: 10.3390/ijms21030887. PMID: 32019109; PMCID: PMC7036753.
• Jacob B, Park IS, Bang JK, Shin SY. Short KR-12 analogs designed from human cathelicidin LL-37 possessing both antimicrobial and antiendotoxic activities without mammalian cell toxicity. J Pept Sci. 2013 Nov;19(11):700-7. doi: 10.1002/psc.2552. Epub 2013 Sep 17. PMID: 24105706.
• Mishra B, Epand RF, Epand RM, Wang G. Structural location determines functional roles of the basic amino acids of KR-12, the smallest antimicrobial peptide from human cathelicidin LL-37. RSC Adv. 2013 Nov 14;(42):10.1039/C3RA42599A. doi: 10.1039/C3RA42599A. PMID: 24307932; PMCID: PMC3844289.

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。