Ⅱ型糖尿病的红细胞膜GPA基因表达

为了研究Ⅱ型糖尿病（ＮＩＤＤＭ）患者红细胞膜血型糖蛋白Ａ（ＧＰＡ）的基因表达,采用不连续聚蔗糖（Ｐｅｒｃｏｌ）密度梯度法分离１５名正常人和２５例ＮＩＤＤＭ患者外周血的网织红细胞,提取其总ＲＮＡ,继以Ｎｏｒｔｈｅｒｎ斑点杂交观测此两组的红细胞膜ＧＰＡ基因的表达水平．采用碱性磷酸酶酶联免疫检测完成红细胞膜ＧＰ的Ｗｅｓｔｅｒｎ印迹．结果表明,ＮＩＤＤＭ患者组红细胞膜ＧＰＡ的ｍＲＮＡ含量较正常人组显著增加（分别为１１．９２±１０．５和１０．１８±１．０８积分光密度,Ｐ＜０．０１）．免疫印迹图谱显示,有６例ＮＩＤＤＭ患者的区带３ａ、３ｂ界限模糊,３例的区带３ａ、３ｂ和４明显浅染．推测ＮＩＤＤＭ患者红细胞膜ＧＰＡ减少可能引起其基因表达呈代偿性增强,而障碍或许出现在翻译环节上,这些与ＮＩＤＤＭ患者红细胞变形能力（ＲＣＤ）的明显降低甚为相符．     

植原体免疫主导膜蛋白Imp基因原核表达载体构建及表达

旨在构建植原体免疫主导膜蛋白Imp基因原核表达载体,并进行初步表达。以重组克隆质粒pMD18-T-Imp为模板,PCR扩增Imp基因片段。构建表达载体pET-28a(+)-Imp,转化宿主菌E.coliBL21(DE3)。筛选阳性克隆,提取重组质粒作PCR鉴定、酶切鉴定及IPTG诱导表达鉴定。PCR及双酶切结果显示,重组质粒pET-28a(+)-Imp构建成功。经IPTG诱导BL21(pET-28a(+)-Imp)表达约20 kD的蛋白,与预期的携带6×His-Tag的目的蛋白(19.5 kD)大小相符,主要以包涵体形式存在。结果显示,构建的表达载体pET-28a(+)-Imp在E.coliBL21(DE3)中能够达一定量表达,为进一步纯化Imp蛋白奠定基础。     

波摩那型钩端螺旋体外膜蛋白LipL32基因片段的克隆表达

目的　构建L3 2_pGEX_5x_2重组质粒 ,诱导表达重组钩端螺旋体外膜脂蛋白LipL3 2。方法　PCR获取编码LipL3 2的基因片段 ,构建重组克隆载体和表达载体 ,转化受体菌 ,诱导表达重组LipL3 2蛋白。将重组LipL3 2蛋白和钩体抗血清进行Western_blot。结果　扩增出约 750bp的LipL3 2成熟蛋白基因 ,LipL3 2基因插入pGEX_5x_2表达载体 ,表达产物谷胱甘肽S_转移酶 (GST ,2 6× 10 3)与LipL3 2蛋白的融合蛋白的相对分子质量约为 53× 10 3 ,与预期大小一致。Western_blot显示重组LipL3 2蛋白能与钩体抗血清特异结合。结论　LipL3 2蛋白能在大肠埃希菌中表达 ,重组LipL3 2蛋白具有免疫反应性     

Potential Difference Across the Nuclear Membrane: A Regulator of Gene Expression?

We propose a model for eukaryotic gene regulaion in which a variable electric field at the nuclear periphery, caused by a potential difference across the inner nuclear membrane, controls macroraolecular interactions, including those between DNA and regulatory proteins. Evidence for the existence of a nuclear membrane potential and DNA contact with the nuclear periphery is presented. The suggestion is made that each cell type is characterized by a specific magnitude of nuclear membrane potential.     

NaCl-Induced Alterations in Both Cell Structure and Tissue-Specific Plasma Membrane H+ -ATPase Gene Expression

NaCl-induced plasma membrane H+-ATPase gene expression, which occurs in roots and fully expanded leaves of the halophyte Atriplex nummularia L. (X. Niu, M.L. Narasimhan, R.A. Salzman, R.A. Bressan, P.M. Hasegawa [1993] Plant Physiol 103: 713-718), has been differentially localized to specific tissues using in situ RNA hybridization techniques. Twenty-four-hour exposure of plants to 400 mM NaCl resulted in substantial accumulation of H+ pump message in the epidermis of the root tip and the endodermis of the root elongation/differentiation zone. In expanded leaves, NaCl induction of plasma membrane H+-ATPase message accumulation was localized to bundle-sheath cells. Ultrastructural analyses indicated that significant cytological adaptations in root cells included plasmolysis that is accompanied by plasma membrane invaginations, formation of Hechtian strands and vesiculation, and vacuolation. These results identify specific tissues that are involved in the regulation of Na+ and Cl- uptake into different organs of the halophyte A. nummularia and provide evidence of the intercellular and interorgan coordination that occurs in the mediation of NaCl adaptation.     

家蚕核型多角体病毒BmNPV囊膜蛋白P74膜外区克隆和原核表达

通过PCR扩增家蚕核型多角体病毒(Bombyx mori nucleopolyhedrovirus,BmNPV)囊膜蛋白p74基因膜外区片段,对切胶纯化得到的DNA目的片段与原核表达载体pET28a进行连接,通过不同浓度的IPTG对含有pET28a-p74重组质粒的大肠杆菌BL21(DE3)进行诱导,对诱导产物进行SDS-PAGE电泳.结果表明p74基因膜外区获得了表达;通过His单抗对原核表达产物进行Western blotting分析,其结果证实诱导蛋白带为融合有组氧酸的目的蛋白.对割胶获得的P74蛋白和免疫佐剂进行克分研磨,以研磨后的匀浆液对昆明小鼠进行皮下多点注射,通过收获的抗血清对BmNPV ODV病毒粒子进行Westem blotting分析,检测到一条分子量大小为74 kD的特异杂交带,表明获得的多抗可用于P74蛋白功能的进一步研究.     

球毛壳菌（Chaetomium globosum）过氧化物膜蛋白过敏原基因克隆、序列分析及原核表达

以球毛壳菌cDNA文库中获得过氧化物膜蛋白（pero）基因片段（GenBank Accn:BP099709）为基础,用RACE 技术获得该基因的全长cDNA序列。序列长747bp,由412bp的3′RACE产物和508bp的5′RACE产物拼接而成。开放阅读框501bp,编码166个氨基酸,蛋白分子量为17.5kD,理论等电点为5.75。利用cDNA两侧非编码区序列作引物克隆出该基因的DNA序列,序列分析表明该基因由2个内含子和3个外显子组成。ClustalX多序列比对表明：该基因与粗糙脉孢菌（Neurospora crassa）的过氧化物膜蛋白过敏原同源性最高（83%）。将pero基因编码区克隆到原核表达载体pET28a中,构建成表达质粒pET28a-pero并转化大肠杆菌BL21,IPTG诱导后SDS-PAGE检测表达情况,结果发现在21kD处有一特异性融合蛋白带,大小与预期相符,说明该基因已经在大肠杆菌中表达。克隆的cDNA序列、DNA序列及推测的氨基酸序列在GenBank登录(登录号分别为AY555771,AY584753,AAS66898)。     

致病钩体表层膜蛋白新基因（Lslp）的克隆表达及免疫原性研究

克隆表达钩端螺旋体表层膜蛋白新基因Lslp并分析表达产物的免疫原性。根据前期研究得到的致病钩体新基因Lslp(GenBankAF32 5 80 7)的序列设计引物 ,在 6株致病钩体中扩增Lslp基因并测序。以BamHⅠ酶切Lslp和pGEX 1 λT ,构建重组质粒并用酶切和PCR鉴定 ,进一步在大肠杆菌中诱导表达 ,并进行免疫印迹分析 ;纯化表达产物免疫家兔 ,ELISA检测血清抗体滴度。结果显示Lslp在 6株致病钩体中均能扩增出相应片段 ,且序列同源性达到99 6 % ;构建高效原核表达重组质粒pGST LslP ,经IPTG诱导在大肠杆菌中可表达出 6 6kDGST融合蛋白 ,并能与全钩抗血清发生免疫印迹反应 ;将上述融合蛋白免疫新西兰大白兔产生 1 :5 1 2 0高滴度的IgG抗体。研究结果提示致病钩体膜蛋白新基因Lslp可在大肠杆菌进行高效表达 ,表达产物能被全钩抗血清识别 ,为研究钩体的致病机制和筛选保护性抗原提供了基础     

柞蚕核型多角体病毒基因表达载体系统的构建与基因表达

柞蚕是一种野外饲养的经济昆虫,主要分布在我国东北部山区。柞蚕以蛹滞育越冬,其蚕蛹个大、容易固定、保存时间长、无须饲养、容易运输等优点。利用柞蚕蛹作为生物反应器生产外来蛋白质,可以大规模机械化生产,减少操作上的烦琐和劳动力。本文利用柞蚕核型多角体病毒(AnpeNPV)作为基因表达载体,在柞蚕培养细胞(AnPe细胞)和柞蚕蛹中成功地表达了β-半乳糖苷酶基因（LacZ）,并利用AnPe细胞筛选、纯化获得了AnpeLacZ重组病毒。该重组病毒的β-半乳糖苷酶产量,在TC-100(含10%FBS)培养的AnPe细胞中最高酶活性为感染后第12天的40.9 units/ml,在SF-900Ⅱ培养的AnPe细胞中最高酶活性为感染后第18天的59.9 units/ml,后者表达量稍高,但时间滞后。AnpeLacZ在5℃保存了7个月的柞蚕蛹中,感染后第15天酶活性达到最高,雌蛹14.3 units/g,雄蛹11.7 units/g,雌蛹比雄蛹略高。结果显示,柞蚕核型多角体病毒和柞蚕蛹可以作为一个可以机械化大规模生产的新型杆状病毒基因表达载体系统开发和利用。     

Gene Expression Analysis

The response of cells to extracellular signals usually requires altered expression of many genes, possibly including several distinct metabolic pathways. In some cases, only a subset of genes involved in such responses are known, which requires techniques to analyze changes in the expression of multiple genes, both known and unknown. Three techniques, two‐dimensional gel electrophoresis, differential display, and gene discovery arrays, provide opportunities for measuring changes in gene expression levels, as well as for identifying novel gene products.