α-芋螺毒素ArIB[V11L,V16D]多肽偶联药物与荧光探针的设计与合成

Design and synthesis of peptide-drug conjugates and fluorescent probe based onα-conotoxin ArIB[V11L,V16D]

α-芋螺毒素Ar IB[V11L,V16D]是目前已知最优的α7乙酰胆碱受体(nicotinic acetylcholine receptor,n ACh R)高选择性抑制剂。为探索该毒素的化学改造方法,丰富其在靶向n ACh R方面的应用,本研究利用连接子分别将喜树碱和7-氨基-4-甲基香豆素与Ar IB[V11L,V16D]的[2,4]位二硫键共价连接,构建了两个多肽偶联药物(peptide-drug conjugate,PDC)Ar IB[V11L,V16D]-5与Ar IB[V11L,V16D]-6和一个荧光标记肽Ar IB[V11L,V16D]-7;细胞毒活性评价结果表明两个PDC对非小细胞肺癌细胞系A549的IC_(50)分别是喜树碱的1.3倍与4.1倍,其活性在细胞水平上略有降低且与连接子结构相关;荧光光谱扫描结果表明荧光标记肽的激发波长与发射波长分别为340与403 nm,该荧光标记肽未发生荧光淬灭且保留了标记物7-氨基-4-甲基香豆素的荧光特性。该修饰改造为α-芋螺毒素Ar IB[V11L,V16D]在PDC与荧光探针方面的进一步应用奠定坚实基础。

α-Conotoxin ArIB[V11L,V16D]is currently the most optimal selective inhibitor ofα7 nicotinic acetylcholine receptor(nAChR)known.In order to explore chemical modification methods and enrich its application in targeting nAChR,this study utilized the linker to covalently connect camptothecin and 7-amino-4-methylcoumarin to the[2,4]disulfide bond of ArIB[V11L,V16D].Therefore,two peptide-drug conjugates(PDCs),ArIB[V11L,V16D]-5 and ArIB[V11L,V16D]-6,and one fluorescent-labeled peptide,ArIB[V11L,V16D]-7 were constructed.Cytotoxicity evaluation showed that the IC_(50)values against non-small cell lung cancer cell line A549 of the two PDCs were respectively 1.3 and 4.1 times of camptothecin,indicating slight reduction in activity at the cellular level which was related to the linker structure.Fluorescence spectrum scanning revealed that the excitation and emission wavelength of the fluorescent-labeled peptide were 340 nm and 403 nm respectively,and the fluorescence features of 7-amino-4-methylcoumarin as a marker were retained without fluorescence quenching.This modification strategy laid a solid foundation for the further application ofα-conotoxin ArIB[V11L,V16D]in PDCs and fluorescent probes.