柞蚕核蛋白CREB的初步分离鉴定

从柞蚕蛹血淋巴细胞中提取总核蛋白,利用SDS-PAGE法对它进行分离,并采用免疫印迹法对核蛋白CREB进行初步鉴定.核蛋白经电泳分析出现了7条主要的蛋白质谱带,其分子量分别为118,90,55,50,41,20和13 ku.Western blotting结果显示核蛋白与CREB抗体发生了较强的结合反应,在41 ku位置附近出现了清晰的反应条带,推测其可能为柞蚕的CREB蛋白.     

A neuronal antigen in the brains of Alzheimer patients

A monoclonal antibody was prepared against pooled homogenates of brain tissue from patients with Alzheimer's disease. This antibody recognizes an antigen present in much higher concentration in certain brain regions of Alzheimer patients than in normal brain. The antigen appears to be a protein present in neurons involved in the formation of neuritic plaques and neurofibrillary tangles, and in some morphologically normal neurons in sections from Alzheimer brains. Partial purification and Western blot analysis revealed the antigen from Alzheimer brain to be a single protein with a molecular weight of 68,000. Application of the same purification procedure to normal brain tissue results in the detection of small amounts of a protein of lower molecular weight.     

家蚕类胰岛素相关肽结合蛋白2（BmIBP2） 的原核表达与组织特异性分析

【目的】从体外表达家蚕中新发现的1个免疫球蛋白超家族成员-类胰岛素相关肽结合蛋白2（BmIBP2）,并制备其多克隆抗体,为进一步深入研究BmIBP2的生物学功能奠定基础。【方法】以家蚕中肠的总cDNA为模板,利用普通PCR方法,扩增出BmIBP2基因的成熟肽序列;通过构建重组表达质粒pET-28a-BmIBP2对BmIBP2的成熟肽进行重组表达;制备多克隆抗体,通过免疫共沉淀的方法研究BmIBP2蛋白的组织特异性。【结果】SDS-PAGE电泳分析表达产物发现,重组蛋白rBmIBP2主要以包涵体的形式表达,目的蛋白大小约为30 kD;以兔抗His-tag抗体为一抗进行Western blot检测,结果表明rBmIBP2具有良好的免疫反应性;用镍离子亲和层析的方法可获得纯化的rBmIBP2,以纯化的rBmIBP2为抗原免疫新西兰白兔制备多克隆抗体,Western blot结果显示家蚕的中肠组织匀浆液中有1条约28 kD大小的条带,大小与BmIBP2成熟肽的蛋白分子量基本一致,而脂肪体、血淋巴、丝腺、精巢及卵巢的组织匀浆液中没有检测到特异反应条带。【结论】成功地实现了BmIBP2在大肠杆菌中的表达和纯化,并获得其多克隆抗体,Western blot结果证明BmIBP2被正确表达,并明确了该蛋白只在家蚕中肠表达的组织特异性。     

Effects of Monoclonal Antibody Against Porcine 40-kDa Adipocyte-Specific Membrane Protein on Endocrine Secretion in Pigs

The present study was to investigate the effect of monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein on endocrine secretion in pigs, in order to provide the evidence for application of this antibody to reduce excessive fat deposition in pig production. 40 Landrace×Saba pigs were randomly divided into 8 groups： 2 control groups were given saline with 10 mL, respectively, and the 6 treatment groups were given monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein with 0.1, 0.5, and 1.0 mg ·kg^-1 body weight at 15 or 60 kg body weight, respectively, all treatments were performed by intraperitoneal injection. The results showed that this monoclonal antibody could significantly reduce serum insulin level and increase levels of serum growth hormone （GH）, insulin-like growth factor-1（IGF-1）, triiodothyronine （T3）, and tetraiodothyronine （T4） either at 15 or 60 kg body weight injection. However, more marked effect was observed at 15 kg body weight treatment. Moreover, the dose-dependent effect of this monoclonal antibody on endocrine secretion was also observed. This result revealed that this monoclonal antibody increased secretion of hormones regulating fat lysis and reduced secretion of hormones regulating fat synthesis, suggests the reduction of porcine excessive fat deposition by this monoclonal antibody was carried out through affecting hormones regulating fat metabolism.     

eGFP标记狂犬病病毒G基因与EgM123基因重组融合蛋白的表达与鉴定

【目的】反向遗传学技术构建EgM123基因重组狂犬病SRV₉病毒疫苗株,研究狂犬病病毒G基因、细粒棘球绦虫EgM123基因、eGFP基因重组质粒在真核细胞中的蛋白表达效果与蛋白免疫原性,为通过反向遗传学拯救eGFP标记EgM123基因重组狂犬病病毒,制备狂犬病-包虫病二联基因重组疫苗提供研究基础。【方法】将已构建的携带eGFP增强型绿色荧光蛋白的狂犬病病毒G基因重组细粒棘球绦虫EgM123基因重组质粒(3033 bp)利用脂质体转染方法转染BHK-21细胞,使其在BHK-21细胞中表达出融合蛋白,并通过荧光显微镜观察、SDS-PAGE聚丙烯酰氨凝胶电泳、Western blotting试验鉴定融合蛋白的荧光蛋白表达、融合蛋白分子量,鉴定其免疫原性。【结果】在转然后48 h可见绿色荧光蛋白的表达;通过SDS-PAGE聚丙烯酰氨凝胶电泳结果显示,重组质粒在BHK-21细胞中表达获得分子量约为120KDa的融合蛋白;Western blotting结果显示,将蛋白凝胶转移PVDF膜分别经狂犬病病毒G蛋白单克隆抗体、EgM123多克隆抗体、GFP单克隆抗体分别孵育,均在120KDa处可见抗原抗体结合条带。【结论】eGFP标记的狂犬病病毒G基因重组细粒棘球绦虫EgM123基因重组质粒在真核细胞中成功表达出融合性蛋白,且具有免疫原性,     

新基因RSTA14-44在大肠杆菌中的表达及抗体制备

RSTA14-44 基因是中国协和医科大分子生物学试验室在研究中获得的一个新基因,全长 1124 bp,可读编码框自 100bp~684 bp,编码 194 个氨基酸,预测其编码蛋白质分子量为 21.8 KDa。构建了包含 RSTA14-44 cDNA 全部编码框的 pET30a(+)-14 表达载体质粒,经过聚丙烯酰氨凝胶电泳纯化,免疫家兔制备了抗 RSTA14-44 抗体。Western免疫印迹分析表明,该抗体具有较高的反应性和特异性,适合用作 RSTA14-44 蛋白的进一步研究。     

Specific endocrine tissue marker defined by a monoclonal antibody

One of two mouse monoclonal antibodies (LK2H10) produced by hybridoma technology against a human endocrine tumor (pheochromocytoma) demonstrated specific immunoreactivity for 69 normal and neoplastic endocrine and tissues known to contain secretory granules. This immunoreactivity was specific, since other normal tissues, tumors from endocrine cells without granules, and tumors from other nonendocrine tissues were negative when tested with antibody LK2H10. The antibody reacted with human fetal adrenal medulla and human pancreatic endocrine cells and with adrenal medullary cells from monkeys and pigs. The antigen detected by antibody LK2H10 is associated with cytoplasmic secretory granules, has an estimated molecular weight of 68,000, and may be related to human chromogranin.     

兔支气管败血性波氏杆菌fimN基因的原核表达

应用PCR方法扩增兔支气管波氏杆菌(Bb)的菌毛蛋白基因( fimN),将fimN基因克隆到表达载体pET-28a(+)中,获得重组质粒pET28a-fimN。将此重组质粒转化受体菌BL21后,用IPTG进行诱导表达,SDS-PAGE结果显示表达蛋白分子量大小约为27 kD,与理论预期值相符。用Western-blot试验分析纯化的表达产物,结果表明,该重组蛋白能与Bb阳性血清发生特异性反应。     

Catalytic hydrolysis of vasoactive intestinal peptide by human autoantibody

Vasoactive intestinal peptide (VIP) labeled with 125I, [Tyr10-125I]VIP, can be hydrolyzed by immunoglobulin G (IgG) purified from a human subject, as judged by trichloroacetic acid precipitation and reversed-phase high-performance liquid chromatography (HPLC). The hydrolytic activity was precipitated by antibody to human IgG, it was bound by immobilized protein G and showed a molecular mass close to 150 kilodaltons by gel filtration chromatography, properties similar to those of authentic IgG. The Fab fragment, prepared from IgG by papain treatment, retained the VIP hydrolytic activity of the IgG. Peptide fragments produced by treatment of VIP with the antibody fraction were purified by reversed-phase HPLC and identified by fast atom bombardment-mass spectrometry and peptide sequencing. The scissile bond in VIP deduced from these experiments was Gln16-Met17. The antibody concentration (73.4 fmol per milligram of IgG) and the Kd (0.4 nM) were computed from analysis of VIP binding under conditions that did not result in peptide hydrolysis. Analysis of the antibody-mediated VIP hydrolysis at varying concentrations of substrate suggested conformity with Michaelis-Menton kinetics (Km). The values for Km (37.9 X 10(-9) M) and the turnover number kcat (15.6 min-1) suggested relatively tight VIP binding and a moderate catalytic efficiency of the antibody.     

Ras p21 as a potential mediator of insulin action in Xenopus oocytes

The oncogene protein product (p21) of the ras gene has been implicated in mediating the effects of a variety of growth factors and hormones. Microinjection of monoclonal antibody 6B7, which is directed against a synthetic peptide corresponding to a highly conserved region of p21 (amino acids 29 to 44) required for p21 function, specifically inhibited Xenopus oocyte maturation induced by incubation with insulin. The inhibition was dose-dependent and specific since (i) the same antibody had no effect on progesterone-induced maturation, (ii) immunoprecipitation and Western blotting indicated that the antibody recognized a single protein of molecular weight 21,000 in oocyte extracts, and (iii) inhibition was not observed with identical concentrations of normal immunoglobulin. Thus, p21 appears to be involved in mediating insulin-induced maturation of Xenopus oocytes. Furthermore, the mechanism may involve phosphorylation of p21, as p21 was found to be a substrate of the insulin receptor kinase.     

尼罗罗非鱼Hsc70的原核表达和多克隆抗体制备

通过原核表达系统表达尼罗罗非鱼热休克蛋白Hsc70,纯化该蛋白并制备其多克隆抗体。对尼罗罗非鱼热休克蛋白进行生物信息学分析,设计特异性引物,扩增出Hsc70基因,通过双酶切与pET-28a构建重组质粒表达载体,并转入大肠埃希菌B21中通过诱导剂IPTG进行原核诱导表达,表达产物用SDS-PAGE鉴定并用镍柱进行纯化。将纯化后的重组蛋白免疫日本大耳兔制备多克隆抗体,用ELISA测定抗体效价,Western blot检测抗体特异性。结果表明,原核表达系统成功表达了尼罗罗非鱼热休克蛋白Hsc70,重组蛋白分子量约为75 ku,主要以包涵体形式表达。经镍柱纯化得到高纯度的Hsc70;该蛋白免疫日本大耳兔获得特异性多克隆抗体,效价为1∶2 048 000;Western blot检测到一条75 ku的特异性条带,表明该抗体能特异性地识别尼罗罗非鱼Hsc70蛋白。尼罗罗非鱼Hsc70蛋白在大肠埃希菌中成功表达,制备的重组蛋白和多克隆抗体为深入研究尼罗罗非鱼Hsc70的功能提供了分子工具。     

卷须链霉菌木聚糖酶B的纯化

为了进一步研究链霉菌木聚糖酶的酶学性质，探讨了卷须链霉菌一种木聚糖酶的纯化方法。粗酶液经硫酸铵饱和度为20％～50％的分级沉淀和Q-sephrose FF离子交换柱层析2步纯化，得到一种电泳纯的木聚糖酶。定名为XynB；酶蛋白纯化倍数达到10．0倍，酶活力回收率达到24．0％。SDS-PAGE结果表明，该木聚糖酶的分子质量为22．0ku，属于低分子质量的木聚糖酶。     

壳聚糖防治金叶女贞褐斑病的研究

[目的]对壳聚糖防治金叶女贞褐斑病的效果进行了研究,为壳聚糖在防治金叶女贞褐斑病上的应用提供参考。[方法]采用病原菌的分离培养及人工感染的方法,对壳聚糖体外抑制金叶女贞褐斑病菌以及预防和治疗金叶女贞褐斑病进行了试验。[结果]3种分子量的壳聚糖体外抑菌效果都很好,其中分子量5万～6万效果最好,1万～2万次之,6000效果稍差;壳聚糖预防试验中,分子量5万～6万和1万～2万的预防效果都很好,在2.0%浓度时,可以达到免疫效果,分子量6000的效果较差,感病率51.37%～83.32%;治疗效果与治疗时间关系密切,24h施药时各分子量的2.0%浓度也达到免疫效果;36和48h施药时分子量1万～2万和5万～6万的高浓度治疗效果不错,其他均较差。[结论]分子量5万～6万、浓度1.5%～2.0%的壳聚糖预防和治疗金叶女贞褐斑病,能够达到很好效果,治疗时间以感菌后48h以内为好。     

磺胺间二甲氧嘧啶(SDM)单克隆抗体的制备及初步鉴定

用磺胺间二甲氧嘧啶人工免疫原(BSA-SDM)免疫Balb/c小鼠,利用细胞融合技术筛选抗磺胺间二甲氧嘧啶单克隆抗体(SDMmAb)杂交瘤细胞,体内诱生腹水法制备SDMmAb,并鉴定其免疫学特性;鉴定结果表明,筛选出3株杂交瘤细胞,单克隆抗体的蛋白亚型为IgG1;分子量为178.1KDa,染色体数目为76～87条。与其他7种磺胺药(SD、SMM、SMZ、SQ、ST、PST、SMT、SPD)有很高的交叉反应性,可用于推广磺胺类药物多残留快速检测试剂盒的研制应用。     

小麦自噬相关基因ATG4和ATG8的原核表达及蛋白纯化

细胞自噬与植物生长、发育和逆境响应等过程密切相关。本研究构建了小麦重要自噬相关基因TaATG4a和TaATG8h的原核表达载体并导入大肠杆菌。IPTG诱导表达后的蛋白质SDS-PAGE电泳结果表明,两个基因在大肠杆菌中均能够高效表达,表达重组蛋白的分子量与预测分子量基本一致。利用Ni柱亲和层析方法进一步获得了纯度较高的重组蛋白,为今后的体外酶活分析、抗体制备和Western杂交等研究奠定了基础。     

Primary Study on Experiment of Tetraploid Induction in Haliotis discus hannai with PEG

The experiment was performed on induction tetraploid of Haliotis discus hannai at two-cell stage through cell fusion with PEG treatment. In this paper, the orthogonal experiment of three factors and three levels [L9 (34)] was used. Three factors and three levels were molecular weight of PEG: 8 000, 6 000, 4 000 mol·g-1; PEG concentration: 45%, 50%, 55%; treatment duration time: 1, 2, 3 min, respectively. The results showed that the optimal pattern of three factors and three levels on inducing tetraploid of Haliotis discus hannai at two-cell stage through using PEG treatment were: molecular weight 4 000, concentration 55%, treatment duration time: 2 min. The highest tetraploid induction rate was 10.8% at embryo period. The three factors treatment sequence was treatment duration time→concentration→molecular weight.     

甜菜夜蛾卵黄原蛋白多克隆抗体制备及其在不同发育时期蛋白表达

【目的】制备甜菜夜蛾(Spodoptera exigua)卵黄原蛋白(vitellogenin,Vg)多克隆抗体,并检测甜菜夜蛾不同发育时期血淋巴中的Vg蛋白表达量变化,为进一步研究Vg转运与利用机制以及生物学功能打下基础。【方法】以羽化24 h的甜菜夜蛾雌成虫c DNA为模板,通过PCR扩增得到甜菜夜蛾Vg基因片段,其包含vitellogenin-N结构功能区。将Vg目的片段连入pMD-19T载体后进行测序,利用DNAMAN软件分析该基因序列的准确性及编码蛋白的特性。将测序正确的Vg基因片段通过Nde Ⅰ和Xba Ⅰ限制性内切酶连接到原核表达载体pCzn1。将重组表达载体pCzn1-Vg转入大肠杆菌Arctic Express,离心收集诱导表达的菌液,超声波破碎菌体沉淀,取上清液与沉淀进行SDS-PAGE检测,分析Vg重组蛋白的可溶性。在不同温度、不同浓度IPTG条件下诱导表达Vg重组蛋白,筛选最优表达条件。经Ni-NTA琼脂糖凝胶亲和层析柱纯化得到了Vg重组蛋白,将该蛋白免疫新西兰白兔,制备兔抗Vg血清抗体。采用间接ELISA方法检测血清抗体的效价,并通过Western blot法检测甜菜夜蛾雌虫不同发育阶段血淋巴中Vg蛋白的表达差异。【结果】扩增所得Vg基因片段为2 091 bp,编码697个氨基酸,预测蛋白分子量为80.88 k D。通过大肠杆菌表达出的Vg重组蛋白相对分子量为80 k D,其大小与预期的Vg重组蛋白带大小相符合。其主要以包涵体形式表达,而在上清中表达量不明显。不同温度、不同浓度IPTG条件下诱导表达Vg重组蛋白的结果显示温度为25℃,IPTG浓度为0.6 mmol·L~(-1)时,Vg重组蛋白表达量最高。继续提高温度和IPTG浓度,对提高Vg重组蛋白的表达量无明显作用,且杂蛋白增多。新西兰白兔经4次免疫后,间接ELISA法检测表明,制备的兔抗Vg抗体具有较好的灵敏度,效价达到1﹕512 000。Western blot检测Vg蛋白在甜菜夜蛾不同发育阶段血淋巴中的表达,其杂交出的单一条带在180 k D左右。Vg蛋白在甜菜夜蛾雌蛹末期开始微弱表达。雌成虫羽化后血淋巴中Vg蛋白表达量先升高后降低,呈动态变化,到羽化48 h表达量最高,随后降低。【结论】纯化获得了Vg重组蛋白,并明确了最优表达条件(温度为25℃,IPTG浓度为0.6 mmol·L~(-1));制备了高效价的甜菜夜蛾Vg多克隆抗体,明确了甜菜夜蛾Vg蛋白的表达规律。     

鲤鱼春季病毒血症病毒磷蛋白基因的克隆与原核表达

【目的】克隆鲤鱼春季病毒血症病毒（SVCV）的磷蛋白（P蛋白）基因,并对其进行原核表达,为进一步制备SVCV-P蛋白单克隆抗体及建立新的SVCV诊断方法奠定基础。【方法】采用RT-PCR方法扩增SVCV P蛋白基因,将其克隆入pET-28a(＋)载体中,获得原核重组表达质粒pET28-P,进行原核表达。将该重组原核表达质粒转化至大肠杆菌Rosetta感受态细胞中,用0.4 mmol/L IPTG进行诱导表达,用镍亲和层析试剂盒对表达产物进行纯化,分别用SDS-PAGE和Western Blotting方法对表达产物进行鉴定。【结果】成功克隆了SVCV-P蛋白基因,该基因长度为933 bp。成功构建了原核重组表达质粒pET28-P,其诱导表达产物分子质量约为37 ku;表达的重组P蛋白可被SVCV阳性血清所识别。【结论】成功克隆了SVCV P蛋白基因,获得了分子质量约为37 ku的重组P蛋白。     

重组鸡白细胞介素2的诱导表达与生物学活性测定

 将去除信号肽的鸡IL-2基因编码框克隆到原核表达载体pBAD/His B，实现了重组鸡IL-2(rchIL-2)蛋白在大肠杆菌中的高效表达。SDS-PAGE分析显示，表达蛋白的分子量约为18 kD。用rchIL-2为抗原制备了单克隆抗体和多克隆抗体，建立了检测rchIL-2含量的抗原捕获ELISA，探讨了天然chIL-2蛋白的体外表达动力学。非变性条件下纯化的rchIL-2 (0.4 ng) 对Con A活化的鸡T淋巴细胞具有明显的增殖活性，而对鸭及鹅的T淋巴细胞无增殖活性。抗chIL-2多克隆抗体可完全中和rchIL-2和天然chIL-2蛋白的生物学活性，而单克隆抗体无中和rchIL-2和天然chIL-2蛋白生物学活性的功能。这些研究结果证实，大肠杆菌表达的rchIL-2及其多克隆抗体拥有生物学功能，而获得的单克隆抗体不具有chIL-2的中和特性。