Evidence for the Existence of Cross-Linked Intermediates during Unfolding and Refolding of CK in UGGE

IntroductionCreatine kinase ( CK) plays an important role incell energy metabolism[1] .It catalyses thereversible transfer of a phosphoryl group fromATP to creatine generating phosphocreatine andADP.Owing to its importance in bioenergetics,CK has been extensively studied.There are fourisoforms of the enzyme:muscle type( MM) ,braintype ( BB) ,hybrid type ( MB) ,and mitochondriatype( Mi Mi) .Muscle- CK is a dimer composed of twoidentical subunits,both with relative molecularmass of4.3×…     

基于Pro/E二次开发实现复杂钣金件的展开设计

基于P ro/E软件建构了钣金件的实体模型及其工程图,以P ro/E提供的二次开发工具P ro/TOOLK IT为基础,通过建立参数关系和编写控制程序完成了参数的获取、传递及修改,实现了只需在U I对话框中输入参数而不需修改源程序代码便可以实现多种相似钣金件的设计、展开及其二维工程图的生成和输出.     

鸡溶菌酶和重组大肠杆菌融合蛋白(NADP-GDH)体外分子交联的初步研究

用PCR方法克隆的大肠杆菌NADP特异性谷氨酸脱氢酶 (NADP specificglutamatedehydrogenase ,NADP GDH)基因和其突变基因 ,插入表达载体pTrcHisC构建重组蛋白质表达体系 .经过IPTG诱导表达 ,用Talon固定化金属亲和层析树脂纯化出重组的天然和突变NADP GDH ,将它们和溶菌酶 (Lysozyme)通过热诱导去折叠方法进行体外蛋白质分子交联实验 ,在去折叠反应液中加入还原剂二硫苏糖醇 (DTT)后 ,不但没有分子间二硫键交联形成 ,同时也没有其他分子间共价键 (异肽键 )交联的形成 .另外 ,半胱氨酸残基定点突变后的NADP GDH重组蛋白质 ,无法参与形成分子间二硫键 ,实验证实经过热诱导去折叠后也没有分子间共价键 (异肽键 )交联 .这些结果进一步证明蛋白质分子间二硫键的形成能够促进蛋白质其他分子间共价键 (异肽键 )的形成 .     

试论高职院校职业指导的开展与推动

高职院校的职业指导有利于高职院校根据市场需求来定位自身的发展，有利于增强办学活力，促进招生、就业，但目前高职院校在职业指导的开展中普遍存在着管理者思想不够重视、没有建立配套的职业指导课程体系、符合资格的职业指导教师严重匮乏等问题。因此，高职院校首先要树立正确的职业指导观，其次是要完善学校职业指导课程体系，再次是要建立“双赢”的学校职业指导机制。此外，还要提高职业指导的专业化水平，从而推动职业指导工作迈上新台阶。     

汽车车架厚板冲压件毛坯展开CAD

汽车车架厚板冲压件的毛坯展开,目前尚无商品化软件可直接应用,文章提出一种实用的几何展开计算方法,并编制出相应的软件,结合工艺试验中获得的数据和经验,可较精确地估算出局部拉伸区材料流动的规律,自动生成汽车车架厚板冲压件毛坯展开图     

A conformationally isoformic thermophilic protein with high kinetic unfolding barriers

The basis for the stability of thermophilic proteins is of fundamental interest for extremophile biology. We investigated the folding and unfolding processes of the homotetrameric Thermoanaerobacter brockii alcohol dehydrogenase (TBADH). TBADH subunits were 4.8 kcal/mol less stable towards guanidinium chloride (GdmCl) unfolding compared to urea, indicating ionic modulation of TBADH stability. Strongly denaturing conditions promoted mono-exponential unfolding kinetics with linear dependence on denaturant concentration. Here TBADH unfolded >40-fold slower when extrapolated from urea as compared to GdmCl unfolding. A marked unfolding hysteresis was shown when comparing refolding and unfolding in urea. An unusual biphasic unfolding trajectory with an exceptionally slow phase at intermediate concentrations of GdmCl and urea was also observed. We advocate that TBADH forms two distinctly different tetrameric isoforms, and likely an ensemble of native states. This unusual supramolecular folding behavior has been shown responsible for formation of amyloidotic yeast prion strains and can have functional importance for TBADH. Received 9 November 2007; received after revision 19 December 2007; accepted 8 January 2008     

奇奇核~(86)Nb的能谱统计

用粒子 转子理论模型计算奇奇核86Nb低自旋下的能谱 ,研究了不同自旋下能谱最近邻能级间距分布(NNS)和能谱刚性度 (Δ3 )的特点 ,并就影响能谱统计特征的因素进行了分析     

参数具有对称性的等变分歧问题的通用开折

讨论分歧参数带有对称性的等变分歧问题在左右等价群的一个子群下的开折,分别给出了其开折是平凡和通用的充要条件.     

奇奇核^84Y的能谱统计

用粒子－转子模型计算奇奇核＾８４Ｙ低自旋下的能谱,重点研究不同自旋下能谱最近邻能级间距分布（ＮＮＳ）和能谱刚性度（△３）的特点,并就影响能谱统计特征的因素进行了分析。