团头鲂卵壳蛋白的分离与纯化

报道了一种从团头鲂卵壳中提取卵壳蛋白的有效方法。该提取淮经SDS－PAGE电泳鉴定后,证明有三条主要的蛋白带,其分子量分别为64KDa,56KDa和52KDa,借助于制备型SDS－PAGE电泳和电洗脱分离纯化技术,获得了三种高纯度的印壳蛋白。     

抗汉坦病毒NP scFv基因表达及生物活性分析

诱导已构建的重组质粒pGEX-6P—1—scFv原核表达抗汉坦病毒核衣壳蛋白单链抗体,并用酶免疫实验检测单链抗体生物活性。用IPTG诱导重组原核表达质粒pGEX-6P-1-scFv表达抗汉坦病毒NP单链抗体融合蛋白,经亲和层析纯化,并应用SDS—PAGE电泳检测单链抗体融合蛋白,应用酶免疫实验检测抗NP单链抗体生物学活性。SDS—PAGE电泳检测显示,原核重组质粒pGEX-6P-1-scFv已表达分子量约为56ku的单链抗体融合蛋白;酶免疫实验检测显示,单链抗体具有与汉坦病毒NP抗原特异性结合的生物学活性。结果表明,已构建的原核表达重组质粒pGEX-6P-1-scFv,能够成功表达具有与汉坦病毒NP抗原特异性结合生物学活性的单链抗体。     

人工合成草鱼生长激素cDNA在大肠杆菌中的表达

经密码子优化的人工合成草鱼生长激素cDNA与表达载体pET-28a( )重组,构建重组表达质粒PET－GH。转化在肠杆菌BL21（DE3）,筛选阳性克隆,IPTG诱导表达,12．5％的SDS－PAGE分析显示,大肠杆菌表达产物中含有与草鱼生长激素分子量一致的新增蛋白带,激光密度扫描,其产量约占菌体总蛋白的40％,金属离子螯合层析柱亲和纯化,获得电泳纯的重组蛋白。Western-blotting和酶联免疫吸附受体法检测证实,重组蛋白与抗草鱼生长激素的多克隆抗体发生特异性结合;复性合的重组蛋白有与天然草鱼生长激素一致的生物学活性。     

苏云金杆菌4.0718菌株杀虫晶体65kD原毒素的质谱分析

以苏云金杆菌4.0718菌株杀虫晶体65kD原毒素为材料,探索了从SDS－PAGE胶上回收蛋白质进行质谱分析的方法。蛋白纯化的步骤包括SDS－PAGE、电洗脱、脱盐、除SDS。电洗脱采用半透膜法,用超滤法脱盐,冷丙酮沉淀法除去SDS。结果表明,纯化的65kD原毒素经ESI－MS检测,分子量约64500Da。经MALDI－MS检测,未能有明显蛋白峰出现,这可能是该蛋白由于较强的疏水作用,溶解性差,在与基质混合时处于聚和悬浮态所致。     

汉坦病毒结构蛋白表位研究进展

汉坦病毒主要引起人类的两种疾病:肾综合征出血热和汉坦病毒肺综合征,汉坦病毒基因组由L、M、和S三个片段组成,分别编码病毒的RNA聚合酶、囊膜糖蛋白G1、G2和核衣壳蛋白NP。本文综述了核衣壳蛋白、囊膜蛋白G1和G2的B细胞表位和CTL表位的研究进展。     

黑素转铁蛋白在家兔网织红细胞膜上的表达及其在铁摄取中的作用

目的：研究黑素转铁蛋白（p97）在家兔网织红细胞膜上的表达及其在非转铁蛋白结合铁摄取中的作用。方法：聚丙烯酰胺凝胶电泳（SDS＝PAGE）和放射性同位素法（^59Fe）。结果：①网织红细胞孵育液浓缩后,经SDS－PAGE测定,在分子量97kD位置上可见一条明显的蛋白带;用磷脂酚肌醇磷脂酶C（PI－PLC）300mu/ml预处理网织红细胞后,孵育液浓缩再经SDS－PAGE测定,在分子量97kD处仍有一条明显的蛋白带,且其平均OD值高于未经处理的网织红细胞;而成熟的红细胞在此处却没有明显的蛋白带。②单纯用PI－PLC作用于网织红细胞,其铁摄取无明显变化（P＞0.05）。③去除内源性转铁蛋白后,再用PI－PLC作用网织红细胞,则胸浆内铁及整合到血红素中的铁均较未经处理的网织红细胞明显降低（P＜0.05）。结论：p97可能存在于家兔网织红细胞膜上,且在摄取非转铁蛋白结合铁的过程中可能发挥作用。     

γ-谷氢酰转肽酶的纯化及其特性的研究

从胎肝和肝癌组织中纯化的 GGTP,经4%—30% PAGE 鉴定氛明分成二部分,其中第一部分活力最强,经亲和层析柱吸附后,免疫动物获纯的抗血清.该部分 GGTP 经10% PAGE 显示一条带,其分子量为92kD,pI 值为4.2.但经 SDS-PAGE 则显示二条蛋白带,其分子量分别为64kD 和27kD.酶免疫抑制试验表明该抗血清对 GGTP Ⅱ,Ⅱ’具有抑制作用,双扩散免疫试验产生单一沉淀线,并互相融合在一起.说明二种组织来源的 GGTP 的免疫学特性相一致.     

汉坦病毒H8205部分核壳蛋白基因在E.coli中的表达

根据汉坦病毒H8205株NP基因的序列,设计一对引物,扩增NP前292个氨基酸多肽基因片段,克隆于表达载体pGEX-3X,与载体中26kD的谷胱苷肽巯基转移酶(GST)融合表达.SDS-PAGE显示表达产物(GST-NP)主要以包涵体形式存在.Western-blotting表明此融合蛋白有抗原性.包涵体经分离、洗涤、溶解后,Sepharose 6B层析纯化,用此融合蛋白作抗原,进行ELISA法检测临床HFRS病人标本的IgG和IgM,有很好的特异性和敏感性.有生物活性的汉坦病毒H8205 NP的体外表达成功,为汉坦病毒基因工程抗原的大量制备奠定了基础,也为汉坦病毒的临床检测和流行病学调查提供了一种廉价、安全、可靠的抗原.     

肾综合征出血热病毒R22株核蛋白基因的克隆序列分析及其表达

为研究肾综合征出血热病毒疫苗侯选株R22核蛋白的结构与特性,应用逆转录PCR扩增了R22编码区基因,并将扩增产物克隆于pET-3a表达质粒,测得R22株S片段编码区序列为1290个核苷酸。比较分析表明与Seoul型同源性高达96．2％,而与Hantaan型同源性仅为71．0％,与用血清学分型的结果一致。将克隆的pET－R22NP转化到BL21后,IPTG诱导得到较高效的表达,产物纯化后进行Westernblot分析,结果表达的NP仅与NP蛋白特异的单克隆抗体A35和3D9反应,而与G2蛋白特异的3D8不反应。表达的产物为汉坦病毒的诊断提供了特异性抗原。     

大肠杆菌脑微血管内皮细胞侵袭基因ibeB的编码产物为外膜蛋白前体

为进一步探讨大肠杆菌脑微血管内皮细胞侵袭基因ibeB的生物学特性 ,将ibeB基因克隆到pET2 8a(+)载体 ,以E .coliBL2 1 (DE3)为宿主菌 ,经IPTG诱导后 ,通过Ni2 + NTA树脂提纯IbeB蛋白 .SDS PAGE确定纯化蛋白的分子量 ;应用无蛋白酶的体外转录和翻译系统进一步鉴定ibeB基因表达蛋白的分子量 ;通过 [3 5S]Met标记的体内T7表达体系并结合膜蛋白分离技术定位IbeB蛋白在细菌中的亚细胞分布 ;利用细菌侵袭实验分析IbeB蛋白抗体对E .coliK1侵袭人脑微血管内皮细胞的封闭作用 .结果发现 ,ibeB基因的重组蛋白表达纯化产物呈现出 5 0kD和 34kD两种分子量大小 ,5 0kD存在于表达细菌的可溶性部分 ,而 34kD则存在于包涵体中 ;体外翻译实验也显示出较弱的 5 0kD和较浓的 34kD两个蛋白带 ;体内T7表达体系实验显示 34kD的IbeB成熟蛋白定位于E .coli的外膜 ;抗 34kDIbeB蛋白抗体能封闭E .coli对人脑微血管内皮细胞的侵袭 .这些结果提示 ,大肠杆菌脑微血管内皮细胞侵袭基因ibeB的编码产物为 5 0kD的外膜蛋白前体 ,该前体可通过分子内剪接形成成熟的 34kDIbeB蛋白     

Diversity of seed storage protein patterns in wild peanut (Arachis,Fabaceae) species

55 accessions of wild peanuts (Arachis spp.) introduced from South America were analyzed for seed storage protein composition using SDS-PAGE electrophoresis. The objectives of the study were to evaluate variability within sect.Arachis and to classify taxa based on protein composition. 25 different band positions were resolved. Individual accessions had 11 to 18 bands which included the conarachin region (MW > 50 kD), two to five bands in the acidic arachin region (MW 38–49.9 kD), three to seven in the intermediate MW region (23 to 37.9 kD), two to five bands in the basic arachin region (18–22.9 kD), and one to three bands in the low MW protein region (14–17.9 kD). These data were utilized in a principal coordinate analysis based on the matrix of genetic distances between all pairs of the 55 accessions. Several groups of accessions conformed to expected species classification includingA. batizocoi, A. stenosperma, andA. monticola; whileA. duranensis, A. cardenasii, A. helodes, andA. correntina did not form good groups. The study showed that great diversity exists for protein profiles and seed storage proteins have potential for aiding species classification and for serving as markers for interspecific hybridization studies.     

莲子贮存蛋白的主要亚基及积累模式

红莲（NelumbonuciferaGaertn）成熟于叶总蛋白含量达24．35g／100g干样品,其贮存蛋白（SP）的积累模式与豆科种子相似,即随成熟度的提高,SP猛增至占总蛋白含量的86％以上。对莲子不同发育阶段子叶蛋白SDS-PAGE图谱的光密度测定表明：莲子叶蛋白有12个主要SP亚基（SP1－12）。按分子量（MW）大小和积累顺序可分3组：A组是98kD和93kD的2个亚基,MW最大,积累最晚,但量最多;B组是3个亚基,MW为55－50kD,大小居中,积累最早,量最少;C组的7个亚基MW最小,在27－14kD之间,积累较早,量较多。对莲的不同品种、不同器官进行分析后发现,它们都有1个主峰为68kD的多连峰的代谢蛋白亚基,可能是莲共有的蛋白亚基。     

汉坦病毒H8205株G1P基因片段重组杆状病毒表达载体的构建及表达

将汉坦病毒H8205株G1P基因的保守序列(约1000bp)作为目的基因插入到BactoBac杆状病毒表达系统的pFastBacHTb供体质粒中,利用Tn7转座子同BacmidDNA同源重组,获得了含目的基因片段的重组杆状病毒DNA,并利用其转染Sf9昆虫细胞,72h后收集细胞悬液,再用该悬液侵染Sf9昆虫细胞,48h后收获病毒.采用IFA分析收获的产物,观察到了特异性的荧光,并且采用SDSPAGE和Western印迹也获得了与预期一致的结果.证明感染后的Sf9昆虫细胞所表达的蛋白中含有能与抗汉坦病毒H8205株多克隆抗体特异性结合目的蛋白.研究表明,采用杆状病毒表达系统可以成功表达出汉坦病毒H8205株包膜糖蛋白G1基因片段,为开发适合的以G1P为抗原的汉坦病毒诊断试剂进行了前期的探索.     

Protein Electrophoretic Analysis of Amyloplast and Cytoplasm Ribosomes from Lotus Cotyledon

Amyloplasts and cytoplasmic ribosomes in cotyledon cells of lotus (Nelvmbo nucifeva Gaertn. ) have been observed on the basis of morphology. Isolation of these ribosomes by centrifugation through 30% to 55% (W/V) sucrose density gradient resulted in three bands of amyloplasts ribosomes and four bands of cytoplasmic ribosomes. The authors used these ribosomes bands for SDS-PAGE electrophoresis to analyse ribosomes of proteins. The patterns of SDS-PAGE between cytoplasmic ribosomes of proteins and amyloplasts ribosomes of proteins were different. The amyloplasts ribosomes of proteins showed 26 kD and 23 kD bands, and the cytoplasmic ribosomes of proteins showed 65 kD band. The analysis of electrophoretic patterns of the cytoplasmic ribosomes of proteins showed that there was a newly synthesized ribosomes protein with 19 kD molecular weight in 18 to 20 days after fertilization.     

Electromicrographic Analysis Storage Protein Accumulation in Endosperms of Maize with Qualified Protein

The characteristics of storage protein accumulation of maize with qualified protein (MQP) and 02 maize were analysed basing on the genetical and biochemical point of views. The 22 kD and 20 kD zeins in the developing endosperms of maize accumulated 15 days after pollination. The structural genes encoding 22 kD and 20 kD zeins in the developing endosperms were simutaneously expressed. In the endosperms of MPQ and o2 maize the synthesis of 22 kD and 20 kD zeins was suppressed. That is to say, o2 gene negatively regulated the synthesis of 22 kD and 20 kD zeins. Two-dimentional electrophoretic analysis of zeins in the maize endosperms further revealed the effects of o2 gene and its modifiers on the synthesis of zeins. In Mol7 and Mo17/o2 endosperms the synthesis of 27 kD, 22 kD, 20 kD and 15 kD zeins was severely suppressed. In 041/oz and 040/o2 endosperms little difference existed SDS-PAGE analysis of the soluble proteins of Mol 7 and Mo17/o2 endosperms revealted that two bands with molecular weight (MW) of 38.7 kD and 26.7 kD were present in wild type but absent in o2 mutant, while two bands with MW 27.2 kD and 26.1 kD were present in o2 mutant but absent in wild type. These differences were resulted from the effect of o2 gene. In 040/02 and 041/o2 endosperms two bands with MW 18.6 kD and 17.6 kD were present in 041/o2 but absent in 040/02 while one band with MW 40. 2 kD was present in 040/02 and absent in 041/o2, which was closely related to the effects of the modifiers of o2 gene.     

优质蛋白玉米胚乳贮存蛋白积累的电泳分析

玉米胚乳的２２ ｋＤ和２０ ｋＤ醇溶蛋白在授粉后１５ 天开始积累,编码２２ ｋＤ 和２０ ｋＤ醇溶蛋白的结构基因在胚乳发育过程中同时表达。优质蛋白玉米和ｏ２ 玉米的胚乳中,２２ ｋＤ和２０ ｋＤ醇溶蛋白的合成受到抑制,即ｏ２ 基因对２２ ｋＤ和２０ ｋＤ醇溶蛋白的合成有负的调节作用。Ｍｏ１７／ｏ２ 和Ｍｏ１７ 胚乳醇溶蛋白的双向电泳结果表明,Ｍｏ１７／ｏ２ 的２７ ｋＤ、２２ ｋＤ、２０ ＫＤ和１５ ｋＤ醇溶蛋白的合成均受到强烈的抑制。遗系０４１／ｏ２ 和遗系０４０／ｏ２ 胚乳醇溶蛋白的双向电泳结果表明,二者只在高分子量的蛋白质斑点区域有一些细微的差别。可溶性蛋白的ＳＤＳ－ＰＡＧＥ分析表明,Ｍｏ１７／ｏ２ 胚乳的可溶性蛋白比其同型系Ｍｏ１７ 少３８．７ ｋＤ 和２６．７ ｋＤ两条谱带,多２７．２ ｋＤ和２６．１ ｋＤ两条谱带。二者出现的可溶性蛋白的差异是ｏ２ 基因调控的结果。遗系０４１／ｏ２ 胚乳的可溶性蛋白比其同型系０４０／ｏ２ 多１８．６ ｋＤ和１７．６ ｋＤ两条谱带,少４０．２ ｋＤ 一条谱带,这与ｏ２ 基因修饰因子的作用密切关联     

苏云金杆菌伴孢晶体的蛋白质和抗蛋白酶多肽及其毒力特性

以SDS-聚丙烯酰胺凝胶电泳分析了19种苏云金杆菌伴孢晶体的蛋白质和抗胰蛋白酶多肽。以鳞翅目的家蚕和双翅目的致倦库蚊进行了毒力测定。根据蛋白质和抗酶多肽的特性,19种晶体可分为7个类型。晶体蛋白质的组成、溶解特性及抗酶多肽的性质与其对两种昆虫的毒力特性密切相关。含分子量为130—138 kD(千道尔顿)或130—138 kD及60一65kD蛋白质,抗蛋白酶多肽(PRP)为68—75kD的晶体,对家蚕高毒,但绝大部分对库蚊无毒或微毒。含3种以上蛋白质(15一138kD),抗酶多肽为35—65kD的晶体,对库蚊有强烈毒性,对家蚕则无毒。缺少135kD蛋白质的两种晶体对家蚕低毒。HD一282和L—14晶体的P1蛋白质中同时含有杀鳞翅目和杀蚊毒素。讨论了伴孢晶体的蛋白质结构及结构与毒力之间的关系、晶体蛋白质及毒性肽的性质在菌株定向筛选和遗传工程研究中的意义。     

Isolation and Characterization of Photosystem Ⅱ of Porphyra yezoensis Ueda

The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were solubilized with SDS, the photosystem Ⅱ (PSⅡ) particles were isolated and purified. The activity of PSⅡ     

Common epitopes of protein antigens in Neisseria and Moraxella

Cross reactions between N. meningitidis and M. catarrhalis proteins were studied with the use of a panel of monoclonal antibodies to M. catarrhalis protein antigens. All antigenic preparations under study were shown to give cross reactions between N. meningitidis serotype porin of 39 kD (strain B125) and M. catarrhalis proteins of 40-41 kD. These M. catarrhalis proteins belonged to main proteins of class F and had the function of porins in the cell. In addition, the epitope of 41-kD antigen, detected by monoclonal antibodies 3E10, is common for both N. meningitidis porin and N. meningitidis iron-regulated proteins of 70 and 50 kD. The epitope of M. catarrhalis protein of 67 kD, detected by monoclonal antibodies 1G6, is common for N. meningitidis porin and N. meningitidis iron-regulated proteins of 50 and 55 kD.