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1.
通过原核表达系统表达奥氏奥斯特他线虫(Ostertagiaostertagi)巨噬细胞转移抑制因子(OoMIF),并对该蛋白的酶功能进行鉴定。通过GenBank和NematodeV3.0数据库发表的序列,利用分子生物学软件设计了1对特异的引物,通过RT—PCR扩增OoMIF全基因,经测序分析后,将OoMIF亚克隆到pET28a(+),然后将鉴定为阳性的重组质粒转化到BL21中用IPTG进行诱导表达。利用HPLC对可溶性表达的重组OoMIF蛋白进行纯化,同时通过免疫印迹对线虫自身的MIF及纯化后的OoMIF进行鉴定,最后对OoMIF的互变异构酶和氧化还原酶活性进行鉴定。结果表明OoMIF具有互变异构酶活性,但没有氧化还原酶活性。为进一步探究OoMIF生物学功能及其MIF在宿主免疫调节中的作用提供依据。  相似文献   

2.
为筛选犬新孢子虫保护性抗原,克隆表达犬新孢子虫巨噬细胞转移抑制因子(MIF)并对其免疫原性进行分析。根据GenBank公布的犬新孢子虫MIF(NcMIF)序列,利用分子生物学软件设计2套特异性引物,以NcMIF mRNA反转录产物为模版,采用PCR扩增出NcMIF基因和2种突变基因NcMIFm和NcMIFhis,选用原核表达载体pET26b,分别构建重组质粒pET26b-NcMIF和pET26b-NcMIFm。重组质粒分别转入E.coli BL21(DE3)中进行表达,纯化后的蛋白利用免疫印迹法进行鉴定。结果显示,rNcMIF和rNcMIFm这2种重组蛋白在BL21(DE3)表达菌株中均为可溶性表达,诱导表达最佳条件为30℃诱导3h IPTG诱导浓度为1mmol/L;Western blot分析结果表明,该表达产物能与抗rNcMIF绵羊血清发生反应,说明获得的蛋白具有较好的抗原性和特异性。  相似文献   

3.
CD63是巨噬细胞表面的跨膜蛋白,已经证实其对人类免疫缺陷病毒Ⅰ型(HIV-Ⅰ)在人巨噬细胞中的复制有重要作用。为了探讨马传染病病毒与巨噬细胞的相互作用,对马巨噬细胞的表面蛋白(CD63)进行体外表达,通过跨膜区分析软件分析CD63蛋白的跨膜结构,利用分子克隆技术构建不同片段大小的重组质粒,并进行原核表达及诱导条件的优化。结果表明:全长CD63在原核系统中不表达,截短CD63蛋白为包涵体表达,当低温诱导时截短CD63可获得可溶性表达,大小约为20 ku。说明成功获得CD63可溶性表达蛋白。  相似文献   

4.
核糖体移码蛋白PA-X是流感病毒的一种新型蛋白,为了研究该蛋白对于猪流感病毒的生物学特性的影响,我们进行了PA-X特有序列的原核表达、蛋白纯化及其鉴定。通过RT-PCR和重叠PCR方法扩增PA-X特有序列的基因,利用基因重组技术构建原核表达载体,并进行菌液PCR和菌液测序鉴定,鉴定正确后克隆转化到BL21(DE3)中,进行蛋白表达及可溶性分析,同时用镍柱亲和层析法对其进行纯化。通过菌液PCR序列鉴定,PA-X特有序列的原核表达载体序列正确,编码框正确。转化BL21后目的蛋白表达成功,且大多数为可溶性蛋白。Western blot结果表明制备的多克隆抗体具有良好的免疫反应性。  相似文献   

5.
本试验对猪脑心肌炎病毒(encephalomyocarditis virus,EMCV)2A蛋白进行原核表达和纯化。采用大肠杆菌原核表达系统,将EMCV 2A基因插入原核表达载体pET-28a-sumo中构建重组原核表达质粒pET28a-EMCV-2A,经PCR和测序鉴定无误。将重组原核表达质粒转化至大肠杆菌BL21(DE3)感受态细胞中,超声破碎后,2A蛋白的表达主要以包涵体形式存在。通过优化蛋白表达条件,使目的蛋白能够实现可溶性表达。利用磁珠纯化方法对重组蛋白进行纯化,并以SDS-PAGE和Western blotting进行双重鉴定。结果显示,本试验成功构建2A的重组表达质粒;重组蛋白分子质量约为25 ku,与预期大小一致;IPTG浓度1.0 mmol/L、16 ℃低温诱导16 h为最佳诱导条件,约有50%的蛋白呈现可溶性表达;纯化后获得2A重组蛋白。本试验通过对EMCV 2A蛋白的原核表达及纯化,成功获得纯度较高的EMCV 2A蛋白,为进一步阐明EMCV的分子致病机制以及研发基因疫苗和抗病毒药物奠定基础。  相似文献   

6.
通过原核表达系统表达猪链球菌Sao-M和Ide_(Ssuis)基因,并分析其反应原性。根据GenBank数据库发表的序列,利用分子生物学软件设计了2对特异性引物,通过PCR扩增Sao-M和Ide_(Ssuis)基因,经测序分析后,分别克隆到pET28a(+)和pMAL-c2X,构建重组表达质粒pET28a:Sao-M和p MAL-c2X:Ide_(Ssuis),然后将鉴定为阳性的重组质粒分别转入宿主菌BL21和Rosetta2中用IPTG进行诱导表达,通过免疫印迹进行鉴定。实验表明,两种重组蛋白在原核系统中获得了高效的表达,并能与相应的阳性抗血清发生特异性反应。本研究为进一步探究Sao-M和Ide_(Ssuis)蛋白生物学功能及其在猪链球菌致病机制上的作用提供了依据。  相似文献   

7.
对犬新孢子虫巨噬细胞转移抑制因子(NcMIF)生物学特性进行鉴定,将NcMIF在大肠杆菌中以3种不同的形式进行表达,三种蛋白分别为NcMIF (成熟的蛋白质),NcMIFm (脯氨酸突变为甘氨酸)和NcMIFhis (在N端添加多组氨酸标记),对三种蛋白的多聚体状态、互变异构酶、氧化还原酶及是否与MIF受体(CD74)结合等进行分析。实验结果显示这三种重组的NcMIFs (rNcMIF)均不具备互变异构酶和氧化还原酶活性;甘氨酸替代脯氨酸的重组NcMIF减少了二聚体和三聚物的形成;N端额外添加的HIS标签增加了三聚物的形成;rNcMIF无法与重组人MIF竞争与MIF受体(CD74)结合,这表明CD74不是NcMIF受体结合;免疫荧光染色结果证明NcMIF定位于犬新孢子虫速殖子的顶端。免疫电镜结果进一步显示NcMIF存在于微线体、棒状体、致密颗粒及细胞核中。为进一步分析NcMIF在寄生虫免疫逃逸过程中发挥的作用提供参考。  相似文献   

8.
为探究水貂细小病毒(MEV)VP2蛋白的结构和功能,对MEV VP2蛋白进行原核表达并纯化,用ELISA初步评价重组蛋白在血清学诊断中的价值。通过大肠埃希菌表达外源基因的方法构建MEV VP2原核表达体系,经诱导表达得到以包涵体形式存在的目的蛋白,对蛋白进行纯化、透析复性并鉴定;加入分子伴侣pTf16质粒构建共表达系统,优化表达条件以提升可溶性目的蛋白的表达量,对表达产物进行纯化及鉴定。将纯化后的可溶性蛋白、复性后的包涵体蛋白及纯化后的全病毒蛋白作为抗原包被酶标板,用间接ELISA方法对MEV标准阴、阳性血清进行检测,初步对比评价3种抗原的血清学诊断价值。结果表明,经过双酶切和测序鉴定,成功构建重组蛋白原核表达载体;重组VP2蛋白的分子质量约为67ku;优化诱导温度和诱导试剂浓度未能解决包涵体表达问题;构建了共表达系统,优化表达条件后可溶性目的蛋白的表达量得到明显提高;SDS-PAGE和Western blot鉴定结果表明,两种重组蛋白皆具有良好的反应原性;间接ELISA结果表明可溶性表达蛋白更适合作为MEV的候选诊断抗原。通过分子伴侣共表达和包涵体蛋白复性的方法获得了大量有活性的目的蛋白,为建立水貂细小病毒血清学诊断方法和制备MEV病毒样颗粒(VLPs)及VP2蛋白多克隆抗体奠定了基础。  相似文献   

9.
为了研究新西兰兔SOD1蛋白分子的结构与功能,设计了一对特异性引物,通过RT-PCR方法克隆得到了该基因编码序列。将该编码序列克隆到分泌型原核表达载体PET-25b,经菌落PCR、双酶切和测序鉴定证实成功构建了重组表达载体。将重组质粒转化大肠杆菌表达菌株E.coli BL21(de3) PlysS,建立了分泌型原核表达系统。IPTG诱导培养重组菌后收集样品检测,经SDS-PAGE、Western blot鉴定,证实在培养物上清中检测到了SOD1蛋白的表达。至此,成功建立了新西兰兔SOD1基因的分泌型原核表达系统,实现了蛋白的可溶表达,为进一步研究该蛋白的结构与功能打下了基础。  相似文献   

10.
参照IBRV基因组序列,设计合成1对特异性引物,扩增了长约846 bp的gD基因片段。将目的片段定向克隆到pET-30a原核表达载体,酶切及测序鉴定均正确后,转化BL21(DE3)表达菌,经IPTG诱导得到了以可溶性形式表达的重组蛋白。重组蛋白纯化后,经免疫印迹检测证明具有良好的抗原性和特异性。本研究利用原核表达系统成功表达具有良好抗原性的gD蛋白,为IBRV的深入研究及诊断试剂的研制奠定了物质基础。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

15.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

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17.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

18.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

19.
正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in  相似文献   

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