B细胞成熟抗原(BCMA)是B淋巴细胞刺激因子(BLyS)的受体之一.它的胞外区与人IgG1Fc的融合蛋白eBCMA-Fc,又称为诱饵受体,具有拮抗BLyS的活性.为了设计新的拮抗肽,基于BCMA和Fc的晶体结构,通过计算机图形学技术、分子模拟方法,建立了eBCMA...B细胞成熟抗原(BCMA)是B淋巴细胞刺激因子(BLyS)的受体之一.它的胞外区与人IgG1Fc的融合蛋白eBCMA-Fc,又称为诱饵受体,具有拮抗BLyS的活性.为了设计新的拮抗肽,基于BCMA和Fc的晶体结构,通过计算机图形学技术、分子模拟方法,建立了eBCMA-Fc融合蛋白的三维理论结构.利用均方根位移(root mean square distance,RMSD)对eBCMA-Fc融合蛋白与单体eBCMA、Fc构象差异进行分析.融合蛋白eBCMA-Fc中的eBCMA段与单体eBCMA的主链碳原子间RMSD值为0.036nm,Fc段与单体Fc的主链碳原子间RMSD值为0.064nm.结果表明,对比单体,融合蛋白eBCMA-Fc并未因eBCMA与Fc直接连接而发生构象的变化.分子对接方法显示,融合蛋白eBCMA-Fc中的BCMA与BLyS作用,而Fc扮演着稳定BCMA构象的支架作用.为进一步验证上述理论分析,构建eBCMA-Fc融合基因,并将载有eBCMA-Fc融合基因的原核表达质粒转化BL21(DE3)菌、在细菌中表达.目的蛋白经蛋白A亲和柱纯化大约为36kD,与理论预测值34kD相近.免疫印迹表明抗人IgG抗体能够识别eBCMA-Fc融合蛋白.ELISA证实,eBCMA-Fc融合蛋白能够结合BLyS.随着eBCMA-Fc融合蛋白增加,结合BLyS的融合蛋白也相应增加.而对照人IgG,即使在高浓度条件下,也不结合BLyS.此外,eBCMA-Fc融合蛋白能够抑制BLyS对B细胞肿瘤Daudi细胞的作用.这些研究为下一步设计和筛选BLyS拮抗肽提供了实验基础.展开更多
Blymphocyte stimulator (BLyS) is also known as B cell activating factor belonging to the tumor necrosis factor (TNF) family (BAFF), or TNF and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-I).^1-...Blymphocyte stimulator (BLyS) is also known as B cell activating factor belonging to the tumor necrosis factor (TNF) family (BAFF), or TNF and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-I).^1-3 As a member of the TNF family, BLyS plays an important role in B cell development, and has been implicated in autoimmune diseases and B cell malignancies.展开更多
文摘B细胞成熟抗原(BCMA)是B淋巴细胞刺激因子(BLyS)的受体之一.它的胞外区与人IgG1Fc的融合蛋白eBCMA-Fc,又称为诱饵受体,具有拮抗BLyS的活性.为了设计新的拮抗肽,基于BCMA和Fc的晶体结构,通过计算机图形学技术、分子模拟方法,建立了eBCMA-Fc融合蛋白的三维理论结构.利用均方根位移(root mean square distance,RMSD)对eBCMA-Fc融合蛋白与单体eBCMA、Fc构象差异进行分析.融合蛋白eBCMA-Fc中的eBCMA段与单体eBCMA的主链碳原子间RMSD值为0.036nm,Fc段与单体Fc的主链碳原子间RMSD值为0.064nm.结果表明,对比单体,融合蛋白eBCMA-Fc并未因eBCMA与Fc直接连接而发生构象的变化.分子对接方法显示,融合蛋白eBCMA-Fc中的BCMA与BLyS作用,而Fc扮演着稳定BCMA构象的支架作用.为进一步验证上述理论分析,构建eBCMA-Fc融合基因,并将载有eBCMA-Fc融合基因的原核表达质粒转化BL21(DE3)菌、在细菌中表达.目的蛋白经蛋白A亲和柱纯化大约为36kD,与理论预测值34kD相近.免疫印迹表明抗人IgG抗体能够识别eBCMA-Fc融合蛋白.ELISA证实,eBCMA-Fc融合蛋白能够结合BLyS.随着eBCMA-Fc融合蛋白增加,结合BLyS的融合蛋白也相应增加.而对照人IgG,即使在高浓度条件下,也不结合BLyS.此外,eBCMA-Fc融合蛋白能够抑制BLyS对B细胞肿瘤Daudi细胞的作用.这些研究为下一步设计和筛选BLyS拮抗肽提供了实验基础.
文摘Blymphocyte stimulator (BLyS) is also known as B cell activating factor belonging to the tumor necrosis factor (TNF) family (BAFF), or TNF and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-I).^1-3 As a member of the TNF family, BLyS plays an important role in B cell development, and has been implicated in autoimmune diseases and B cell malignancies.