| 摘要: |
| 目的:筛选出能影响配体TRAIL功能的死亡受体DR5来源的反义多肽。方法:依据蛋白质密码理论，编写可按参数要求进行氨基酸序列匹配比对的生物学软件，利用该软件对TRAIL(序列Ⅰ)和DR5(序列Ⅱ)进行比对，寻找两序列间的反义同源盒匹配序列。结合蛋白质和配体-受体复合物的结构信息，进一步理论筛选相互作用区域，合成可能与TRAIL作用的小分子活性肽。采用ELISA结合和竞争实验，分析所合成多肽与TRAIL的结合；在TRAIL诱导细胞凋亡实验中，分析与死亡受体竞争结合TRAIL的程度，观察多肽影响TRAIL介导细胞凋亡的生物活性。结果:经软件初筛选和理论分析，共合成10条多肽。通过ELISA结合实验筛选到一条多肽(命名为“FR-11”)，能与TRAIL发生浓度依赖性的特异结合，并能抑制DR5与配体TRAIL的结合。该多肽与TRAIL 97～103aa的匹配率大于50％，计算机模拟三维结构显示该序列位于DR5的胞外区，是与TRAIL结合的关键区域。细胞学实验表明：FR-11肽能够抑制TRAIL介导的SW1990细胞和L929细胞的凋亡，这种抑制作用呈FR-11浓度依赖性，而在TRAIL浓度较低时更为明显，提示能抑制TRAIL与死亡受体的结合。结论:根据蛋白质密码理论设计的软件能筛选出影响配体-受体相互作用的功能反义多肽；某些多肽能模拟受体与配体发生结合，具有抑制配体介导的生物活性。 |
| 关键词: DR5 反义多肽 TRAIL 细胞凋亡 |
| DOI：10.3724/SP.J.1008.2008.00892 |
| 投稿时间：2008-01-20修订日期：2008-05-19 |
| 基金项目:上海市科委生物医药重点攻关项目(034319223). |
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| Synthesis of DR5-derived complementary peptide FR-11 and its inhibitory effect on TRAIL-mediated cell apoptosis |
| GAO Yun,WANG Liang-hua,SUN Ming-juan,REN Na,ZONG Ying,JIAO Bing-hua* |
| (Department of Molecular Biology and Biochemistry,College of Basic Medical Sciences,Second Military Medical University,Shanghai 200433,China) |
| Abstract: |
| Objective:To synthesize DR5-derived complementary peptide(s) that can influence the function of TRAIL and to observe its(their) inhibitory effect on TRAIL-mediated cell death.Methods: A software was designed to identify the matching domains of two known peptide sequences according to the theory of Proteomic Code.The antisense homology box sequences between DR5 and its ligand TRAIL were searched by the designed software.Possibly active peptide(s) was/were selected and synthesized based on the structural information of TRAIL-DR5 complex.The binding between TRAIL molecule and the selected peptide(s) was examined by ELISA; the inhibitory effect of the selected peptide(s) against TRAIL-induced cell death was studied by cellular experiments.Results: Ten complementary peptide sequences were obtained based on software selection and structural analyzing.One active DR5-derived peptide FR-11 was selected with ligand-binding analysis using ELISA; FR-11 showed specific binding to TRAIL in a dose-dependant manner and blocked the binding of TRAIL with DR5.The matching rate between FR-11 and TRAIL 97-103aa was higher than 50%.Computer analysis showed that FR-11 corresponded to the extracellular domain of DR5,a key binding site to TRAIL.Further study indicated that FR-11 inhibited TRAIL-induced apoptosis of SW1990 cells and L929 cells in a dose-dependant manner; the inhibitory effect of FR-11 was more potent when the concentration of TRAIL was low,suggesting that it inhibited the binding between TRAIL and death receptor.Conclusion: The software designed based on the theory of Proteomic Code can be used to select complementary peptides which influence the interaction between ligand and receptor.The selected peptide FR-11 can bind to the ligand TRAIL and subsequently inhibit the biological function of the ligand. |
| Key words: DR5 antisense peptide TRAIL apoptosis |
