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1.
新发PDCoV和TGEV双重RT-PCR检测方法的建立及初步应用 总被引：1，自引：0，他引：1
猪Delta冠状病毒(Porcine deltacoronavirus,PDCoV)是一种新发现的冠状病毒,临床上主要引起感染仔猪出现水样腹泻、呕吐和脱水等症状,和猪传染性胃肠炎病毒(Porcine transmissible gastroenteritis virus,TGEV)感染引起的临床症状极为类似,且临床上PDCoV和TGEV混合感染时有发生,单靠临床诊断很难区分两种疾病,因此建立同时检测且区分PDCoV和TGEV的检测方法具有重要的临床意义.本研究根据GenBank中收录的PDCoVN基因和TGEVN基因序列设计了2对引物,在同一反应体系中同时扩增PDCoV的N基因片段和TGEV的N基因片段,通过对RT-PCR反应条件的优化,建立了同时检测PDCoV和TGEV的双重RT-PCR方法,并对该方法进行了特异性、灵敏性和重复性研究.结果显示,所建立的双重RT-PCR对PDCoV和TGEV的最低检测量分别是3.14×102 copies/μL和3.68× 103 copies/μL,利用该双重RT-PCR方法对猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)、猪博卡病毒(Porcinebocavirus,PBoV)、猪繁殖与呼吸综合征病毒(Porcine respiratory and reproductive syndrome virus,PRRSV)和猪伪狂犬病毒(P.pseudorabiesvirus,PRV)的扩增结果均为阴性,显示出较好的特异性.为了解所建立的双重RT-PCR方法的临床应用效果,对252份临床样品进行了检测.结果表明,双重RT-PCR检出PDCoV阳性样品31份(阳性率为12.30％),TGEV阳性样品12份(阳性率为4.76％),同时感染PDCoV和TGEV的阳性样品2份(阳性率为0.79％),且检测结果与单一PDCoV和TGEV RT-PCR相符.因此,本研究所建立的双重RT-PCR方法可用于PDCoV和TGEV的临床检测,为进一步研究PDCoV和TGEV的临床鉴别诊断和流行病学调查提供了理论依据和技术支持. 相似文献
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根据GenBank中猪圆环病毒2型(Porcine circovirus2,PCV2)的核苷酸序列设计2对引物,使用扩增全基因的引物对来源于河南省焦作、开封和滑县的3株PCV 2型JZ株、KF株和HX株的ORF2基因进行扩增,扩增片段克隆到pMD18 T上,获得重组质粒pMD18-T-ORF2,并对其进行测序,测序结果登录在GenBank上,登录号分别为EF028202、EF064149和EF467928.序列分析表明,PCV2河南分离株ORF2基因与其它PCV2 ORF2基因核苷酸序列同源性为92.4%～99.6%,氨基酸序列同源性为90.6%～97.9%,进化分析表明,河南分离株处于同一分支,与欧洲株亲缘关系较近.应用另一对引物从重组质粒pMD18-T-ORF2中PCR扩增出587 bp不包含核定位信号序列的ORF2基因,克隆到表达载体pET-32a,成功构建了重组质粒pET-32a-ORF2,经IPTG诱导表达了ORF2基因编码的结构蛋白,经SDS-PAGE和Western blotting检测,表达的重组蛋白分子量约为40 kD,可被PCV2阳性血清识别,说明PCV2 ORF2基因得到成功表达. 相似文献
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梅山猪氨肽酶基因N(pAPN)cDNA克隆、序列分析及重要变异位点的筛选 总被引：1，自引：0，他引：1
氨肽酶N(aminopeptidase N,APN)蛋白是猪(Sus scrofa)传染性胃肠炎病毒(Transmissible gastroenteritis virus,TGEV)和猪的流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)等一系列冠状病毒的受体蛋白。为探讨梅山猪APN基因的分子结构特征以及重要的变异位点,本研究通过PCR扩增和测序技术,结合生物信息学分析梅山猪APN基因功能区域和重要变异位点,对其蛋白质结构进行预测和分析。结果表明,梅山猪APN基因cDNA全长2 886 bp(GenBank登录号:KF280271),含有20个外显子,编码961个氨基酸。与GenBank数据库公布的标准序列(登录号:NM_214277.1)相比,梅山猪APN基因编码区变异共引起10处氨基酸突变与2处氨基酸缺失,其中Phe82Asn、Leu107Phe、Leu108 Ile、Ser330Pro、Trp399Arg和Glu465 Gly等6处突变位于APN酶催化活性区域,Gln747His突变、748Tyr和749Ser缺失突变位于APN病毒结合区域。蛋白结构和编码产物功能分析发现,pAPN为不稳定的亲水性蛋白,无信号肽,具有1个跨膜螺旋(跨膜区位于12~34氨基酸,二级结构元件以α螺旋和β折叠为主,编码产物主要参与细胞被膜(cell envelope)、中央中间代谢(central intermediary metabolism)、辅酶因子生物合成(biosynthesis of cofactors)等功能。Gln747His、748Tyr和749Ser缺失突变可能与氨肽酶N结合病毒能力有关。本研究对梅山猪pAPN基因功能的分析及变异位点的筛选,为今后筛选猪抗病毒性腹泻的有效遗传标记提供理论基础。 相似文献
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猪传染性胃肠炎病毒(TGEV)S蛋白5'端基因重组腺病毒的构建及其免疫特性 总被引：2，自引：0，他引：2
RT-PCR扩增出猪传染性胃肠炎病毒（Transmissible gastroenteritis virus, TGEV）S蛋白基因5'端包含 B、C抗原位点的1.0 kb DNA片段,并与穿梭载体pShuttle-CMV连接;然后与腺病毒（Adenovirus）骨架载体pAdEasy-1共转化大肠杆菌（Escherichia coli）BJ5183,通过同源重组获得重组腺病毒质粒。该重组腺病毒质粒转染HEK293细胞并进行噬斑纯化,获得了1株含有TGEV S蛋白5'端基因的重组人复制缺陷型血清5型腺病毒rAd-TGEV-S。随后用RT-PCR和间接免疫荧光（indirect immunofluorescent assay, IFA）检测目的基因的转录与表达。重组腺病毒rAd-TGEV-S在HEK293细胞连续传代9次后,病毒效价稳定,滴度平均为107. 7TCID50/mL。动物免疫试验显示, rAd-TGEV-S可以诱导小鼠产生TGEV特异性IgG和IgA。 相似文献
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根据GenBank中猪2型圆环病毒的核苷酸序列,设计两对引物,对来源于河南省不同地市的4株PCV2细胞培养物进行鉴定,并扩增出ORF2基因,克隆到pMD18－T载体上,获得重组质粒pMD18-T-ORF2,并对其进行测序,结果表明所克隆的ORF2基因与其它PCV2 ORF2基因核苷酸同源性在92.4%～99.6%之间,氨基酸同源性在90.6％～97.9％之间。同时采用PCR从重组质粒pMD18-T-ORF2中扩增出587bp的ORF2基因,克隆到表达载体pET-32a,成功构建了重组质粒pET-32a-ORF2,经诱导表达了ORF2基因编码的结构蛋白,表达的重组蛋白为融合蛋白,分子量为40kD,经Western-Blot检测,重组蛋白可被PCV2阳性血清识别。 相似文献
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制备兔多杀性巴氏杆菌(Pasteurella multocida,Pm)外膜蛋白A(OmpA)重组蛋白单抗,为兔多杀性巴氏杆菌病的诊断提供特异性强,灵敏度高的单克隆抗体。本研究选取并扩增Pm外膜蛋白基因OmpA,原核表达获得了的大小为37.6kD的OmpA重组蛋白,以纯化复性的兔多杀性巴氏杆菌OmpA重组蛋白作为免疫原,按常规方法免疫BALB/c小鼠(Mus musculus),取其脾细胞与SP2/0细胞融合,ELISA筛选出了4株分泌Pm OmpA蛋白单克隆抗体的杂交瘤细胞,分别命名为5D2、BC11、2A2和6A4。其中2A2细胞培养液效价为1∶256,5D2、BC11和6A4效价为1∶128;2A2腹水效价为1∶12800,其余3株达1∶6400。杂交瘤细胞经反复冻存、复苏及多次传代,仍能稳定分泌高效价抗体。Western blot显示,4株单克隆抗体均能与Pm OmpA重组蛋白重组发生特异性反应。用ELISA方法鉴定2A2单克隆抗体亚型为IgG2b,Protein A亲和纯化2A2腹水抗体,获得的单抗浓度为130μg/mL。选取纯化的2A2单克隆抗体进行潜在应用研究,Western blot与间接免疫荧光结果显示,单克隆抗体能与兔多杀性巴氏杆菌分离菌株发生特异性反应。表明利用体外重组表达兔多杀性巴氏杆菌OmpA融合蛋白制成的杂交瘤能够稳定分泌效价高、特异性强的单克隆抗体,可用于兔多杀性巴氏杆菌诊断,本研究结果为兔多杀性巴氏杆菌诊断试剂盒的研制提供技术参数。 相似文献
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猪传染性胃肠炎病毒（TGEV）S蛋白5′端基因重组腺病毒的构建及其免疫特性 总被引：1，自引：0，他引：1
RT-PCR扩增出猪传染性胃肠炎病毒（Transmissible gastroenteritis virus,TGEV）S蛋白基因5′端包含B、C抗原位点的1.0kb DNA片段,并与穿梭载体pShuttle-CMV连接;然后与腺病毒（Adenovirus）骨架载体pAdEasy-1共转化大肠杆菌（Es-chenchia coli）BJ5183,通过同源重组获得重组腺病毒质粒。该重组腺病毒质粒转染HEK293细胞并进行噬斑纯化,获得了1株含有TGEV S蛋白5′端基因的重组人复制缺陷型血清5型腺病毒rAd-TGEV-S。随后用RT-PCR和间接免疫荧光（indirect immunofluorescent assay,IFA）检测目的基因的转录与表达。重组腺病毒rAd-TGEV-S在HEK293细胞连续传代9次后,病毒效价稳定,滴度平均为10^7.7TCID50／mL。动物免疫试验显示,rAd-TGEV-S可以诱导小鼠产生TGEV特异性IgG和IgA。 相似文献
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利用噬菌体随机7肽库分析猪繁殖与呼吸综合征病毒(PRRSV)N蛋白B细胞抗原表位。以PRRSV BJ-4株N蛋白的单克隆抗体(mAb)GE3作为筛选分子，筛选噬菌体展示的随机7肽库。经序列测定和分子生物学软件分析，表明噬菌体展示的外源氨基酸序列与PRRSV BJ-4株N蛋白的50～55aa的氨基酸序列有极高的同源性。ELISA分析结果表明，筛选到的噬菌体能特异性地与PRRSV阳性血清结合，从而证实了该表位是单克隆抗体GE3所识别的抗原表位。 相似文献
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脂肪特异性磷脂酶A2基因(adipose-specific phospholipase A2,A dPLA)在脂肪组织甘油三酯水解过程中发挥着重要的调节作用,为了构建黄牛AdPLA基因原核表达系统,本研究通过Overlap PCR方法从黄牛(Bos taurus)基因组DNA中得到了AdPLA基因编码区全长,将其克隆到pGM-T载体上,阳性克隆经测序表明,与NCBI公布的序列(GenBank No.NM_001075280)完全一致.阳性质粒经BamH Ⅰ和HindⅢ双酶切后,将其定向重组到pET28a(+)原核表达载体上,转化感受态大肠杆菌(Escherichia coli) BL21 (DE3)中,用IPTG诱导融合蛋白表达.SDS-PAGE电泳表明,融合蛋白His-AdPLA在大肠杆菌中表达,证明成功构建了AdPLA基因原核表达系统,为进一步研究黄牛AdPLA基因的功能和AdPLA蛋白产品开发提供了依据. 相似文献
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Identification of oxidation products of (-)-epigallocatechin gallate and (-)-epigallocatechin with H(2)O(2) 总被引：4，自引：0，他引：4
Zhu N Huang TC Yu Y LaVoie EJ Yang CS Ho CT 《Journal of agricultural and food chemistry》2000,48(4):979-981
(-)-Epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) are two important antioxidants in tea. They also display some antitumor activities, and these activities are believed to be mainly due to their antioxidative effects. However, the specific mechanisms of antioxidant action of tea catechins remain unclear. In this study are isolated and identified two novel reaction products of EGCG and one product of EGC when they were reacted separately with H(2)O(2). These products are formed by the oxidation and decarboxylation of the A ring in the catechin molecule. This study provides unequivocal proof that the A ring of EGCG and EGC may also be an antioxidant site. This study also indicates an additional reaction pathway for the oxidation chemistry of tea catechins. 相似文献
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W R Dantzer J Hopper K Mullin S Hendrich P A Murphy 《Journal of agricultural and food chemistry》1999,47(10):4291-4296
14C-Fumonisin B(1) (FB(1)) was produced by Fusarium proliferatum M-5991 in modified Myro liquid medium and purified to >95% purity with a specific activity of 1.7 mCi/mmol. Nine male and nine female F344/N rats were each dosed by gavage with 0.69 micromol of (14)C-FB(1), (14)C-hydrolyzed FB(1), or (14)C-FB(1)-fructose/kg body weight. Urinary excretion of (14)C-FB(1) and (14)C-FB(1)-fructose was 0.5% and 4.4% of the total dose, respectively, and was similar between male and female rats. Urinary excretion of (14)C-hydrolyzed HFB(1) was significantly greater (P > 0.05) in female rats as compared with male rats (17.3% vs 12.8% of the total dose, respectively). There were no significant (P > 0.05) differences in biliary excretion of the three fumonisin compounds with a mean of 1. 4% of the dose excreted at 4 h after dosing. Lesser amounts continued to be excreted up to 9.25 h after dosing. Although biliary excretion of the (14)C-FB(1), (14)C-hydrolyzed FB(1), and (14)C-FB(1)-fructose was similar, increased urinary excretion of the (14)C-hydrolyzed FB(1) as compared to (14)C-FB(1) and (14)C-FB(1)-fructose indicated a greater absorption of the hydrolyzed form. 相似文献
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Roy A 《Journal of agricultural and food chemistry》1999,47(12):5209-5210
Terpinolene oxide, a monoterpene belonging to the p-menthane group, is easily derived from naturally abundant (R)-limonene. It was isomerized with montmorillonite clay catalyst to karahanaenone (2,2, 5-trimethylcyclohept-4-en-1-one) by ring enlargement. The enantiomers of the corresponding alcohol, karahanaenol (2,2, 5-trimethylcyclohept-4-en-1- ol), known for their individual organoleptic properties, were resolved through Pseudomonas cepacia lipase mediated enantiospecific alcoholysis of its acetate derivative. 相似文献
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The presence of ethylenediamine-N-(o-hydroxyphenylacetic)-N'-(p-hydroxyphenylacetic) acid (o,p-EDDHA) as the second largest component in commercial EDDHA iron chelates has recently been demonstrated. Here is reported the speciation of o,p-EDDHA by the application of a novel methodology through the determination of the complexing capacity, protonation, and Ca(2+), Mg(2+), Cu(2+), and Fe(3+) stability constants. The pM values and species distribution in solution, hydroponic, and soil conditions were obtained. Due to the para position of one phenol group in o,p-EDDHA, the protonation constants and Ca and Mg stability constants have different values from those of o,o-EDDHA and p,p-EDDHA regioisomers. o,p-EDDHA/Fe(3+) stability constants are higher than those of EDTA/Fe(3+) but lower than those of o,o-EDDHA/Fe(3+). The sequence obtained for pFe is o,o-EDDHA/Fe(3+) >/= o,p-EDDHA/Fe(3+) > EDTA/Fe(3+). o,p-EDDHA/Fe(3+) can be used as an iron chelate in hydroponic conditions. Also, it can be used in soils with limited Cu availability. 相似文献
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S. R. Verma J. P. S. Arora J. S. Shankar R. Chand 《Water, air, and soil pollution》1987,36(3-4):247-257
The effect of protein oxovanadium(V) ion concentration and pH on the ratio of diffusion current (id/id0) was studied in vanadium(V) ovalbumin-S and denatured ovalbumin systems. In both the cases marked decrease in diffusion current was observed at the respective pH values, indicating that binding takes place with cationic groups of the proteins. The binding sites (n) were found to be pH dependent. The uniformity of logK and ΔG 0 value at all pH values indicated the involvement of same sites in interaction. Furthermore, the linear scatchard plots in both the systems supported the involvement of single class of independent sites in oxovanadium(V) anion interaction. The difference in binding sites (n) has been attributed to the folded structure of ovalbumin-S while unfolded one of denatured ovalbumin. 相似文献
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The efficiency of As(III) oxidation by MnO2, and retention of oxidation products varies with system pH. Maximum retention by hydrous Mn(IV) oxide occurs at pH < 5, declining at higher pH to about half total As at pH 10. The adsorption capacities of pyrolusite and cryptomelane at pH ～6.5 for As(V) species were 10 and 25 mmol kg?1, respectively. HMO surface saturation (～10 mmol kg?1) was reached with equilibrium As(V) levels of 5 to 8 × 10?6 M but this was supplemented at higher levels by an absorption process where uptake increased linearly with concentration (e.g., 68 mmol kg?1 with 2 × 10?5 M As(V)). Added As(III) was avidly oxidized and most product retained at pH 3. At higher pH increasing amounts of As(III) remained unoxidized due to initial reactions apparently blocking access to internal pores. Added Na+ reduced the amount of As retained by the HMO, with the phosphate salt having a significant effect. Extraction studies confirmed that most As could be released by exposure to reducing agents or chelating agents (EDTA). The environmental significance of the results has been considered. 相似文献