真核生物集缩素(condensin)的主要作用是在细胞周期过程中调控染色体的动态变化。它是一种含5个亚基的蛋白质,由1个起核心催化作用的SMC2(structure maintenance of chromosomes 2)/SMC4异二聚体和3个起调节作用的非SMC亚基组成。目前,...真核生物集缩素(condensin)的主要作用是在细胞周期过程中调控染色体的动态变化。它是一种含5个亚基的蛋白质,由1个起核心催化作用的SMC2(structure maintenance of chromosomes 2)/SMC4异二聚体和3个起调节作用的非SMC亚基组成。目前,关于集缩素中SMC2/SMC4异二聚体的体内构象和分子作用机制仍不清楚。最近,对SMC2/SMC4异二聚体的结构解析取得许多新进展。该文在简要介绍SMC蛋白的基本结构、真核生物集缩素的发现、真核生物集缩素的结构组成的基础上,对近年来SMC2/SMC4异二聚体的结构解析的研究进展作一综述,以期为相关研究提供参考。展开更多
For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups,...For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.展开更多
文摘真核生物集缩素(condensin)的主要作用是在细胞周期过程中调控染色体的动态变化。它是一种含5个亚基的蛋白质,由1个起核心催化作用的SMC2(structure maintenance of chromosomes 2)/SMC4异二聚体和3个起调节作用的非SMC亚基组成。目前,关于集缩素中SMC2/SMC4异二聚体的体内构象和分子作用机制仍不清楚。最近,对SMC2/SMC4异二聚体的结构解析取得许多新进展。该文在简要介绍SMC蛋白的基本结构、真核生物集缩素的发现、真核生物集缩素的结构组成的基础上,对近年来SMC2/SMC4异二聚体的结构解析的研究进展作一综述,以期为相关研究提供参考。
文摘For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene （TDI） terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared （FFIR）, the gel permeation chromatography （GPC） and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of （60 ±2）℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is （25. 0 ± 0. 5）%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride （0. 4%, mass fraction）, as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.
文摘目的:采用高分辨液质联用技术快速分析和推定泊马度胺胶囊中的降解产物。方法:采用Agilent ZORBAX SB-CN色谱柱(150 mm×4.6 mm,5 mm),以质谱兼容性0.1%甲酸水溶液-甲醇为流动相,梯度洗脱,流速1.0 m L·min^(-1),检测波长为240 nm,对泊马度胺胶囊经酸、碱、高温、氧化及光照破坏产生的有关物质进行分离。通过电喷雾正离子化四极杆-飞行时间质谱(Q-TOF/MS)测定各有关物质的精确分子质量及分子式,再根据二级质谱(MS/MS)碎裂信息推定未知降解产物结构;喷雾电压3.5 k V,雾化器流量11 L·min^(-1),去溶剂气温度350℃,离子源气压310 k Pa,驱簇电压120 V,MS扫描范围m/z 100~1 000,MS/MS扫描范围m/z 50~800,MS/MS碰撞能量10~20 e V。结果:建立的HPLC分析方法下各有关物质与主成分分离良好,在强制降解供试品溶液中共检测到14个主要有关物质,经液质初步分析推定了它们的结构分别为泊马度胺的水解产物(有关物质1、2、3、7和8),3-氨基-1,2-苯二甲酸(有关物质4),2-硝基-6-[[(2,6-二氧代-3-哌啶基)氨基]羰基]-苯甲酸(有关物质5),2-亚硝基-6-[[(2,6-二氧代-3-哌啶基)氨基]羰基]-苯甲酸(有关物质6),N′-[2-(2,6-二氧代哌啶-3-基)-1,3-二氧代-4-异二氢吲哚]-乙酰肼(有关物质9),泊马度胺羟基化产物(有关物质10和12),3-硝基-N-(2,6-二氧-3-哌啶基)苯邻二甲酰亚胺(有关物质11),3-甲基氨基-N-(2,6-二氧-3-哌啶基)苯邻二甲酰亚胺(有关物质13),泊马度胺的羟基化二聚体产物(有关物质14)。结论:新建立的液质联用方法适用于泊马度胺胶囊中有关物质的检查,为泊马度胺制剂质量控制和工艺优化提供重要参考。
