CAJ | 학술논문

东亚钳蝎是一类广泛分布于我国且具有重要药用价值的野生资源.其氯离子通道神经毒素(BmK CT)对人脑神经胶质瘤细胞具有靶向特异性的抑制作用.利用SWISS-MODEL服务器对BmK CT进行蛋白质原子结构的同源建模,利用Insight II软件包对建模结果做能量最小化和分子动力学优化,获得最佳候选模型.三维结构对比分析表明,BmK CT与以色列蝎氯通道毒素(Cltx)三维结构极为相似,均由一个α-helix和两个反向平行的β-sheet构成,但BmK CT属于βαβ型,而Cltx属于αββ型.表面静电势分析表明,BmK CT和Cltx分子表面分布着大量正电势,暗示两分子功能相似,且其中的碱性氨基酸及产生的正电势对其与受体结合起决定作用.采用晶体生长试剂盒(Crystal Screening Kit)中的51个缓冲液配方筛选BmK CT的结晶条件,在7号配方(1.4 mol/L 乙酸钠,0.1 mol/L 甲次砷酸钠,pH 6.51中筛选到柱状六边形晶体.
동아겸갈시일류엄범분포우아국차구유중요약용개치적야생자원.기록리자통도신경독소(BmK CT)대인뇌신경효질류세포구유파향특이성적억제작용.이용SWISS-MODEL복무기대BmK CT진행단백질원자결구적동원건모,이용Insight II연건포대건모결과주능량최소화화분자동역학우화,획득최가후선모형.삼유결구대비분석표명,BmK CT여이색렬갈록통도독소(Cltx)삼유결구겁위상사,균유일개α-helix화량개반향평행적β-sheet구성,단BmK CT속우βαβ형,이Cltx속우αββ형.표면정전세분석표명,BmK CT화Cltx분자표면분포착대량정전세,암시량분자공능상사,차기중적감성안기산급산생적정전세대기여수체결합기결정작용.채용정체생장시제합(Crystal Screening Kit)중적51개완충액배방사선BmK CT적결정조건,재7호배방(1.4 mol/L 을산납,0.1 mol/L 갑차신산납,pH 6.51중사선도주상륙변형정체.
BmK CT,one of the key toxin from Buthus matensii Karsch,has been shown to bind specifically to glioma cell surface as a specific chloride channel blocker. In this study, three dimensional structure of BmK CT was modeled and the crystallization condition of BmK CT was filtrated. Prediction of three dimensional structure of BmK CT was performed by SWISS-MODEL workspace and the quality of generated mode was further examined by energy minimization and molec-ular dynamics (MD) simulation using Insight II 2000 software package. Crystallization of BmK CT was performed using the hanging-drop method. 51 conditions (Crystal Screening Kit, Hampton Research) were used to get good quality and well repeating crystals. The structure of BmK CT and Cltx consisted of a small three-stranded antiparallel β-sheet packed against an α-helix. But BmK CT belonged to βαβ type and Cltx αββ type. The calculated electrostatic potential surface around the BmK CT and Cltx molecule were found to be mainly positive, which suggested that this clustering of positively charged residues and the strong positive field they produce might well have important implications on the interaction with the receptors. The results showed that hexagonal column crystal could be obtained from a condition containing 1.4 mol/L sodium acetate,0.1 mol/L Na cacodylate,pH 6.51,at 4℃ and the protein was dissolved in ddH_2O.