毛腿鼠耳蝠Myotis fimbriatus不同组织酯酶同工酶的比较

采用聚丙烯酰胺不连续凝胶垂直板活性电泳,分析了毛腿鼠耳蝠的心脏、肝脏、肾脏、胸肌、肺、胃、小肠、舌8种组织的酯酶.结果表明:毛腿鼠耳蝠8种组织的酯酶同工酶存在差异,其分布和活性具有明显的组织特异性,与器官或组织所执行的功能有关.     

绿色荧光蛋白标记的NTE活性域表达载体的构建及表达

利用含有特定限制性内切酶识别位点的引物,通过聚合酶链式反应扩增出人神经病靶标酯酶活性域的编码序列,经T载体克隆测序正确后,双酶切回收特异片段定向插入到增强型绿色荧光表达载体pEGFP-N3中,通过酶切反应鉴定,构建了绿色荧光蛋白标记的神经病靶标酯酶活性域的融合表达载体pNEST-EGFP.采用脂质体转染的方法将其转染到人神经瘤母瘤细胞SH-SY5Y中,用荧光显微镜观察发现神经病靶标酯酶活性域分布于细胞质中,而且没有导致内质网膜的聚集,表明表达载体成功构建和表达.     

Characterization of carrot pectin methylesterase

The most alkaline form of pectin methylesterase was purified from ripe carrot roots and used for structural analysis. Determination of an N-terminal blocking group and of the primary structure allowed comparisons with other forms, and facilitated crystallographic determination of the three-dimensional structure. The mature enzyme has 319 residues and the N-terminal blocking group was shown to be a pyroglutamyl residue derived from a glutaminyl cyclization. Few other methylesterases have been isolated and assigned to exact mature forms, and together with the present enzyme, only two have been analyzed in three-dimensional structure. However, comparison of 39 forms, mainly from GenBank data, reveals clear relationships and identifies sub-groups of this enzyme type, deviating in structure but centering around two functionally important and conserved Asp residues at positions 136 and 157 in the carrot enzyme. Received 2 January 2002; accepted 4 January 2002     

嗜热酯酶EstTs1的远源三维结构模建及分子对接

利用Phyre网络服务器,构建嗜热酯酶EstTs1的三维结构,并通过分子动力学优化构型,得到了可靠的构型.分子对接研究表明,p-硝基苯基丁酸酯是EstTs1的最适底物,其大小正适合EstTs1的活性口袋.Thr111是底物与酶结合的重要残基,与底物形成了氢键; Ser85是重要的催化残基.     

Cycles of juvenile hormone esterase activity during the juvenile hormone-driven cycles of oxygen consumption in pupal diapause of flesh flies

Summary During diapause O₂ consumption in fly pupae is a cyclic event (4-day periodicity at 25°C) driven by cycles of juvenile hormone activity. Levels of juvenile hormone esterase activity change systematically during the cycle, with highest activity observed at the nadir of the O₂ consumption cycle.Supported in part by grant 88-37153-3473 from the USDA Competitive Grants Office and grant 23-088 from the USDA Forest Service. Thanks to Dr Ming Tu Chang for her helpful advice.     

酯酶与表面活性剂复配控制OCC浆中的胶黏物

从去除胶黏物以及降低胶黏物黏性角度出发,探讨了酯酶与表面活性剂L64复配处理旧瓦楞箱板（OCC）浆料后,胶黏物的去除效果以及胶黏物黏性的变化．结果表明：与空白样相比,酯酶与表面活性剂L64复配处理OCC浆料对浆中胶黏物有较好的去除效果及降黏效果,并且酯酶与表面活性剂L64复配处理对OCC浆料中的胶黏物去除效果明显优于单独酯酶处理的作用效果;复配处理浆料时,对大胶黏物和微细胶黏物的去除率分别为47．26％、14．29％．纸张物理强度的测定结果表明：酯酶与表面活性剂L64复配处理并不会对OCC纸张物理强度产生负面影响．     

阿魏酸酯酶O42807在毕赤酵母GS115中的表达

研究阿魏酸酯酶O42807基因(fae)在巴斯德毕赤酵母GS115中的表达及重组阿魏酸酯酶的酶学特性.化学合成fae基因序列,构建分泌型重组质粒pPIC9K-fae,经线性化后电转化至毕赤酵母GS115,对筛选出的高活性转化子进行诱导表达.SDS-PAGE分析显示:发酵上清液为单一条带,表观相对分子质量为42 ku,酶活为78.49 nkat·mL^-1,比活力为524.38 nkat·mg^-1,最适反应温度为50 ℃,在40~45 ℃温度范围内较稳定,最适反应p     

槟榔酯酶同工酶的比较分析

采用聚丙烯酰胺凝胶电泳法,测定与分析了不同产地、不同品种、不同器官的槟榔酯酶同工酶酶谱、酶含量、泳动率（ Ｒｆ） 、酶活性及分布状况．结果表明,各酶区新酶带的带位迁移和酶带活性的变化程度与生境、种类、部位不同密切相关     

香菇完全亲和双单杂交初步研究

选用香菇的野生株（Ｑ）与栽培株苏香的４种孢子单核体进行完全亲和双单杂交。运用拮抗试验并辅以液体出菇试验初步鉴定出１２个杂交后代,且对杂交后代酯酶同工酶进行了检测。显著性检验研究表明,大多数杂交后代在菌丝生长速率与ＣＭＣ酶活方面表现了明显的杂种优势,４个代表菌株可产生正常的子实体。酯酶同工酶聚类分析与农艺性状分析表明杂交后代及其与亲本之间都显示了不同程度差异,表明１～１２号菌株是真正的双单杂交后代,认为菌株间酯酶同工酶酶相似系数值可以作为香菇遗传育种选择亲本的辅助的遗传标记。