A mini-library system to investigate non-essential residues of lipid-phosphatidylserine (PS) binding peptide-peptoid hybrid PPS1.
A mini-library system to investigate non-essential residues of lipid-phosphatidylserine (PS) binding peptide-peptoid hybrid PPS1.
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用于研究脂质-磷脂酰丝氨酸 (PS) 结合肽-类肽杂合体 PPS1 的非必需残基的迷你文库系统。
DOI：
10.1039/c7md00372b
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Udugamasooriya,DGomika
中科院分区：
文献类型：
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作者：
Shukla,SatyaPrakash;Udugamasooriya,DGomika
我们最近发现了一种多肽-类肽杂交物PPS1，它能特异性识别脂质-磷脂酰丝氨酸(PS)。PPS1由不同的带正电荷和疏水残基的区域组成。PPS1单体没有活性，但二聚体PPS1D1在体外对肺癌细胞表现出比正常细胞更强的细胞毒性，并抑制了体内肿瘤的生长。PPS1D1的最小药效基团表明，第一个(蛋氨酸)和第四个(N-赖氨酸)残基对PPS1D1的细胞毒活性并不重要。在本研究中，我们进一步研究了这两个残基，特别是位于最重要的四个残基疏水区和两个带正电荷残基之间的第四个残基，以确定这些残基的替换是否可以提高活性或使PPS1D1对结合识别完全不敏感。将第四个带正电的N-赖氨酸取代为具有不同物理化学性质的取代基，如芳香族疏水基团、脂族脂环基团、杂环基团和带负电基团，开发了一个包含39个衍生物的微型文库。对HCC4017肺癌细胞进行标准3-(4，5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium比色法和/或钙黄素AM细胞活力测定，结果表明，PPS1D1第4位对大多数变化不敏感，但负电荷反转对其活性有显著影响。这种观察可能是由于附近的正电荷残基被中和了，这是结合所必需的。此外，通过消除第一位甲硫氨酸来缩短每个单体序列不会影响活性。
We recently identified a peptide–peptoid hybrid, PPS1, which specifically recognized lipid-phosphatidylserine (PS). PPS1 consists of distinct positively charged and hydrophobic residue-containing regions. The PPS1 monomer was inactive, but the dimeric form, PPS1D1, displayed strong cytotoxicity to lung cancer cells compared to normal cells in vitro, and reduced the tumor growth in vivo. The minimum pharmacophore of PPS1D1 showed that the first (methionine) and fourth (N-lysine) residues were not important for PPS1D1 cytotoxic activity. In this study, we further investigated these two residues, in particular the fourth residue that lies between the most important four-residue hydrophobic region and two positively charged residues, to determine whether replacements of these moieties could gain activity improvements or render PPS1D1 totally insensitive for binding recognition. The positively charged fourth residue N-lysine was replaced with substituents having varied physiochemical properties, such as aromatic-hydrophobic, aliphatic-alicyclic, heterocyclic, and negatively charged residues, developing a mini-library of 39 derivatives. The standard 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetric and/or the calcein AM cell viability assays performed on HCC4017 lung cancer cells indicated that the fourth position of PPS1D1 was insensitive to most changes, except that reversal of the negative charge significantly affected the activity. This observation may be due to the neutralization of the nearby positively charged residue that is essential for binding. In addition, shortening each monomeric sequence by eliminating the methionine at the first position did not affect the activity.