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1.
亚洲璃眼蜱免疫抑制蛋白P36的分子鉴定及重组表达   总被引:1,自引:0,他引:1  
为了解蜱吸血和病原传播的分子机制,本研究从亚洲璃眼蜱唾液腺中克隆获得一个编码免疫抑制蛋白P36的同源性基因,该基因全长924bp,编码区为708bp,预测的编码蛋白包含235个氨基酸,分子量为27ku。BLAST分析表明,该基因预测的氨基酸与美洲花蜱和安氏革蜱唾液腺中的免疫抑制蛋白P36高度同源。RT-PCR分析表明,该基因在未吸血成蜱中没有表达,但吸血后表达。将目的基因与载体pGEX-4T-1连接后转化BL21表达菌,经诱导后得到GST融合重组蛋白。该实验结果为进一步研究P36奠定了基础。  相似文献   

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为了进行抗蜱和蜱传病疫苗的研究,本实验对亚洲璃眼蜱雌蜱吸血前后唾液腺消减文库中获取的一个全长编码基因P18进行了研究。该基因全长519bp,共编码170个氨基酸,分子量为18.36Ku,等电点为4.28。BLAST分析表明,该基因预测的氨基酸与肩突硬蜱、篦子硬蜱唾液腺的抗凝血小肽有30%~40%低度同源性。将该基因亚克隆到pET-32a( )表达载体,转化BL21(DE3)宿主菌,经IPTG诱导,重组融合蛋白以可溶性形式高效表达。将可溶性重组蛋白免疫小鼠后获得的抗血清。经免疫印迹分析表明,该重组蛋白抗体可特异性的识别半饱雌蜱唾液腺中的天然蛋白抗原,而未吸血雌蜱唾液腺中则不显现特异条带。RT-PCR结果进一步证实,该基因在蜱吸血后的唾液腺中差异表达。  相似文献   

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为真核融合表达亚洲璃眼蜱(H.asiaticum)唾液腺中的组胺结合蛋白(HBP)与渗透肽TAT,并研究其生物学活性,本研究将编码HBP的基因片段与编码渗透肽TAT基因片段通过酶切位点Eco RⅠ酶切连接后克隆至真核表达载体p Fast Bac HTa中,构建重组杆粒r Bac-HBP-TAT,转染至sf9昆虫细胞中,制备重组病毒并进行融合蛋白的表达。经SDS-PAGE、western blot和间接免疫荧光试验检测结果表明,HBP-TAT在Bac-to-Bac杆状病毒系统中获得稳定表达,融合蛋白约为31 ku。此外,组胺结合试验证明HBP-TAT具有与组胺结合的能力。本研究为研制新型蜱源抗组胺药物提供了实验依据。  相似文献   

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本研究利用RNA干扰技术研究亚洲璃眼蜱p36基因在其生长、发育、繁殖方面的生物学功能。通过注射p36基因的dsRNA成功实现了该基因的表达沉默,干扰组表达量下降了99%。蜱p36基因沉默后,24 h的吸附率下降了50%,饱血率下降了55.5%,卵孵化率下降了100%。结果表明p36基因在亚洲璃眼蜱吸血和繁殖中具有重要作用。  相似文献   

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根据丝氨酸蛋白酶保守性氨基酸序列设计引物,以镰形扇头蜱半饱血雌蜱cDNA为模板,经PCR扩增得到SP30基因的保守区,通过5’RACE(rapid amplification of cDNA Ends)和3’RACE技术得到全长基因。将该基因连入原核表达载体pGEX-4T-1,经IPTG诱导纯化得到重组蛋白。以镰形扇头蜱卵、幼蜱、若蜱、成蜱各发育阶段的cDNA为模板进行Real-timePCR实验。结果显示,SP30基因全长1194 bp,开放阅读框长900 bp,编码299个氨基酸,预计蛋白分子质量30 kDa。Real-time PCR分析结果表明,该基因在四个不同的发育阶段均有不同程度的表达。  相似文献   

6.
为了进行抗蜱及蜱传病疫苗的研究,本研究根据微小牛蜱巴西株报道的一种抗菌多肽核苷酸序列设计引物,从微小牛蜱中国安徽株克隆到该抗菌多肽基因,全长383bp,编码110个氨基酸残基,该蛋白预测的分子量为12.2ku,等电点为4.87.经同源性比较,该微小牛蜱巴西株抗菌多肽基因有100%的相同性.经RT-PCR分析表明,该基因在微小牛蜱卵、幼蜱、半饱血雌蜱、饱血雌蜱和雄蜱这几个阶段均有表达.将该基因亚克隆到pET-28a( )表达载体,转化BL21(DE3)宿主菌,经IPTG诱导,可成功表达.重组融合蛋白大小为15ku左右,与预期大小一致.初步体外抗菌试验表明,重组蛋白具有一定的抗菌活性.Western-blot显示,兔抗微小牛蜱唾液抗体能够识别重组表达蛋白.  相似文献   

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《畜牧与兽医》2015,(5):12-15
P0分子是一种核糖体蛋白,具有抗蜱免疫作用。本文采用RACE技术从镰形扇头蜱(Rhipicephalus haemaphysaloides)中获得了P0全长基因。通过对P0全长基因序列进行分析发现,P0全长基因为1 118 bp,具有一个编码319个氨基酸的开放阅读框,没有信号肽序列。推测P0的蛋白大小约为35 ku。P0与其他蜱种具有很高的同源性,与微小扇头蜱(Rhipicephalus microplus)和长角血蜱(Haemaphysalis longicornis)的P0基因同源性分别为94%和87%。编码区克隆到表达载体p GEX-4T-1中,转化表达宿主菌BL21,可表达出分子量约为60 ku的重组融合蛋白。表达的蛋白以包涵体的形式存在于菌体中。表达产物经GST树脂纯化后可得到纯度较高的目的蛋白。抗P0重组蛋白鼠血清可以识别蜱体内的P0蛋白,大小在35 ku。研究结果将为镰形扇头蜱新型防治技术研究提供基础。  相似文献   

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为克隆和研究柔嫩艾美耳球虫(E.tenella)新基因,本研究在所获得的ESTs序列的基础上,应用RACE技术克隆获得了1个在子孢子阶段高表达新基因的全长cDNA序列(GU553107),命名为ZB7-C11,该基因全长1439bp,ORF为525bp,编码174个氨基酸,预测表达蛋白的分子量约为18.7ku。Real-timePCR对E.tenella不同发育阶段(未孢子化卵囊、孢子化卵囊、子孢子和裂殖子)表达量进行分析显示,该基因在子孢子阶段的表达高于其它阶段。另外,将ZB7-C11克隆于pGEX-4T中构建重组质粒pGEX-4T-C11,转化大肠杆菌BL21(DE3)中,经IPTG诱导表达6h后其表达量最高,并且重组蛋白分子量约44.7ku大部分以可溶性存在。Westernblot分析显示该重组蛋白可被抗E.tenella的多克隆抗血清识别,表明该蛋白具有较好的反应原性。该结果为进一步研究该基因的生物学功能奠定了基础。  相似文献   

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采用RT—PCR技术首次从孤雌生殖长角血蜱四川株克隆到P27/30基因,扩增序列全长670bp,包含完整的开放阅读框,编码201个氨基酸,预测蛋白相对分子质量为23.38ku。同源性分析表明孤雌生殖长角血蜱中国株与日本株P27/30基因同源性高达99.85%。经RT—PCR检测分析,该基因在孤雌生殖长角血蜱的卵、幼蜱、若蜱、饥饿成蜱和饱血成蜱这几个阶段均有表达。将该基因亚克隆后连接到pET32a(+)原核表达载体,转化BL21(DEa)宿主菌,经IPTG诱导可成功进行表达。表达的目的蛋白大小为24ku左右,与预期大小一致;Western-blot显示兔抗长角血蜱全虫抗体能够识别该重组表达蛋白。  相似文献   

11.
Tian Z  Liu G  Zhang L  Yin H  Wang H  Xie J  Zhang P  Luo J 《Veterinary parasitology》2011,181(2-4):282-290
A Haemaphysalis longicornis heat shock protein 70 (HLHsp70) was identified from a cDNA library synthesized from tick eggs. The HLHsp70 cDNA is 2311 bp in length and encodes 661 amino acid residues with the predicted molecular weight of 72.5 kDa and an isoelectronic point (pI) of 5.2. It also contains the highly conserved functional motifs of the Hsp70 family and a specific endoplasmic reticulum (ER) retention signal "KDEL" that is common among ER-localized proteins. The HLHsp70 exhibits 90% amino acid identity to the putative Hsp70 of Ixodes scapularis, and 85% to Gallus gallus 78 kDa glucose-regulated protein precursor. Real time RT-PCR analysis showed that the expression levels of the Hsp70 in ovaries and salivary glands were significantly higher than in other tested tissues in partially fed females. Although the expression level of the HLHsp70 was constantly low in unfed ticks, it was significantly induced by blood-feeding. Further, the expression was positively correlated to the temperature (4-37°C, tested). Western blot analysis showed that the rabbit antiserum against the recombinant HLHsp70 protein (rHLHSP70) recognized bands of approximately 100, 72, and 28 kDa from egg lysates, as well as a 72kDa fragment in protein extracts from partially fed larvae. Immunization of rabbits with the rHLHSP70 did not result in a statistically significant reduction of female tick engorgement and oviposition. These results suggest that although HLHSP70 plays a role in the physiological activities of ticks, as a constitutive protein it was not suitable for selection as a candidate vaccine antigen against ticks.  相似文献   

12.
The most abundant protein present in Boophilus microplus eggs, vitellin, was isolated and purified as a non-covalent complex of six glyco-polypeptides of Mr 44-107kDa. The protein complex bound haem. Immuno-blots demonstrated that antibodies raised to vitellin recognised a 200kDa polypeptide in the haemolymph of adult female ticks. This is consistent with the general proposal that in arthropods vitellin is derived by proteolytic processing from a large precursor protein, vitellogenin. In parallel with this study, an 80kDa glycoprotein (GP80) was independently purified from larvae of B. microplus using efficacy in vaccination trials as an assay. Antibodies to GP80 also recognised a 200kDa protein in the haemolymph of ticks and a major 87kDa polypeptide present in the vitellin complex. Conversely, antibodies to purified vitellin recognised GP80. The amino-terminal amino acid sequences of the 87kDa vitellin polypeptide and GP80 were identical for at least the first 11 residues and internal peptide sequences from both polypeptides were co-located in a single but incomplete deduced amino sequence of B. microplus vitellogenin. Thus, GP80 is a processed product from vitellogenin and highly related to but not completely identical with the 87kDa vitellin polypeptide. Vaccination trials in the model host sheep were performed with purified vitellin and GP80. Sheep vaccinated with either purified vitellin or GP80 returned significantly reduced numbers of engorged female ticks with decreased weights and reduced oviposition. In contrast, sheep vaccinated with recombinant hexahis-GP80, which was incorrectly folded and not glycosylated showed no significant effects on ticks. It was concluded that vitellin and GP80 could induce immune responses that partially protect sheep from the tick, B. microplus. However, critical protective epitopes are associated with the folding of the protein and/or the oligosaccharides attached to it.  相似文献   

13.
Gao J  Luo J  Fan R  Guan G  Ren Q  Ma M  Sugimoto C  Bai Q  Yin H 《Veterinary parasitology》2007,147(1-2):140-149
There should be some differences between antibodies generated by feeding ticks on animals and those derived by immunizing animals with tick extracts. Here, we found serum collected from sheep immunized with Haemaphysalis qinghaiensis salivary gland extracts could detect two more protein bands with molecular weights of 22 and 37 kDa (P22 and P37) on Western blots of extracts of tick salivary glands than serum from tick infected animals. Rabbit anti-H. qinghaiensis differential protein immune serum was then generated from P22 and P37 and was used to immunoscreen a cDNA library constructed from salivary glands, Malpighian tubules and ovaries of partially engorged H. qinghaiensis. A cDNA contains an open reading frame of 483 bp that codes for 160 amino acid residues with a coding capacity of 18 kDa was cloned and designated Hq02. Expression analysis by RT-PCR showed that this gene is expressed in salivary glands, midguts, other organs and different developmental stages of H. qinghaiensis. The predicted amino acid sequence of the Hq02 gene had high homology to some known myosin alkali light chain (MLC) proteins. A fusion protein consisting of 130 amino acids of Hq02 protein and 335 amino acids of T7 gene 10 protein was expressed in Escherichia coli and used to immunize sheep. Western blot showed that only rabbit anti-H. qinghaiensis differential protein immune serum could recognize the expressed Hq02 protein, while rabbit anti-H. qinghaiensis saliva immune could not. This proved Hq02 protein was a "concealed" antigen. Immunization with the recombinant Hq02 conferred a 21.8% reduction of engorgement weight for adult female ticks that fed on the immunized sheep. This is the first report of tick myosin alkali light chain and the function of this protein is discussed.  相似文献   

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Interleukin-17 (IL-17 or IL-17A) is a proinflammatory cytokine produced by activated T cells. IL-17A plays important roles in inflammation and host defense. In this study, the cDNA of the goose IL-17A (GoIL-17A) gene was cloned from thymocytes. Recombinant GoIL-17A (rGoIL-17A) was expressed using a baculovirus expression system and then biologically characterized. The complete open reading frame (ORF) of GoIL-17A contains 510 base pairs that encode 169 amino acid residues, including a 29-amino acid signal peptide and a single potential N-linked glycosylation site. This protein has a molecular weight of 18.9 kDa. The amino acid sequence showed 95.9%, 84.6%, 45.0% and 38.4% similarity with the corresponding duck, chicken, rat, and human IL-17A sequences, respectively. The six conserved cysteine residues were also observed in GoIL-17A. A recombinant, mature form of GoIL-17A was produced and its biological activities in goose embryonic fibroblasts were investigated. RT-PCR analysis revealed a marked up-regulation of IL-6 and IL-8 mRNA expression in goose embryonic fibroblasts treated with 1–50 μg of rGoIL-17A for 12 h. The GoIL-17A gene sequence and the biologically active recombinant protein may be useful for understanding the role of IL-17A in immune regulation.  相似文献   

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【目的】旨在通过分析细胞色素P450家族成员11A1(CYP11A1)的生物信息功能及其在新西兰白兔卵巢颗粒细胞中对繁殖性能相关基因的调控作用,为探究其在卵泡发育过程中调控功能奠定基础。【方法】根据GenBank上兔CYP11A1基因的序列,设计特异性引物,以新西兰白兔卵巢组织cDNA为模板,PCR扩增并克隆CYP11A1基因序列,构建pcDNA3.1-CYP11A1过表达重组载体;用Mega 5.1在线软件构建系统进化树,并通过生物信息学软件对CYP11A1蛋白的氨基酸组成、理化性质、磷酸化位点、保守结构域、二级结构、三级结构、亚细胞定位、蛋白互作进行预测分析。分离新西兰白兔卵巢颗粒细胞,并通过免疫荧光法鉴定颗粒细胞特异性抗体卵泡刺激素受体(FSHR)的表达。设计3条干扰CYP11A1基因表达的引物(siRNA-1、siRNA-2、siRNA-3),筛选出干扰效率最高的1条,并将其与pcDNA3.1-CYP11A1过表达重组载体转染到卵巢颗粒细胞中,用实时荧光定量PCR检测颗粒细胞中羟基类固醇17-β脱氢酶1(HSD17B1)骨形态发生蛋白15(BMP15)和促卵泡刺激素受体(FSHR)等繁殖相关基因mRNA表达水平。【结果】成功克隆新西兰白兔CYP11A1基因,其CDS全长序列为1 557 bp,编码518个氨基酸,其中亮氨酸含量(10.6%)最高,精氨酸(7.6%)、缬氨酸(7.4%)和丙氨酸(7.2%)次之。进化树分析显示,CYP11A1蛋白序列与家鼠、人和猩猩的距离最近。生物信息学分析显示,CYP11A1蛋白理论等电点为7.4,正负电荷残基数各占50个,脂肪族氨基酸指数为82.16,不稳定性指数39.54,其中氨基酸序列中亲水性残基数量多于疏水性残基;CYP11A1蛋白具有40个潜在的磷酸化位点,其中以苏氨酸、丝氨酸和酪氨酸最为丰富;CYP11A1蛋白二级结构由α-螺旋(48.31%)、无规则卷曲(40.22%)、延伸链(7.42%)和β-转角(4.04%)组成,三级结构为弯曲螺旋状。亚细胞定位预测结果显示,CYP11A1蛋白主要分布于线粒体(52.2%)、细胞质(17.4%)和细胞核(13.0%)中,还具有1个p450家族的结构域,并与多个繁殖性能相关的蛋白(STAR、CYP21A2、CYP17A1和FDX1)相互作用。分离的兔颗粒细胞表达FSHR,可以用于后续试验;CYP11A1基因在颗粒细胞中过表达后,HSD17B1和FSHR基因表达量极显著上调(P<0.05),BMP15基因表达量显著上调(P<0.01);干扰CYP11A1基因表达后,BMP15和FSHR基因的表达量极显著下调(P<0.01),HSD17B1基因表达量显著下调(P<0.05)。【结论】CYP11A1是一个稳定、亲水、相对保守且具有抗氧化和类固醇激素合成功能的蛋白。CYP11A1基因可调控卵巢颗粒细胞中与繁殖性能相关的基因HSD17B1、BMP15、FSHR的表达,说明CYP11A1基因在母兔繁殖过程中发挥一定作用。  相似文献   

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We investigated the terminal location of NcSRS2, a surface antigen of Neospora caninum that has potential use for diagnosis, and demonstrated its importance as a vaccine component against neosporosis, in an insect-baculovirus expression system. To examine the role of the hydrophobic C-terminal tail in NcSRS2, four types of recombinant baculoviruses were constructed. Immunoblotting and N-terminal amino acid analysis revealed cleavage of a 6 kDa of the N-terminal signal peptide in the mature NcSRS2 protein. The recombinant NcSRS2 (rNcSRS2) lacking 25, and 62 amino acids from the termination codon were detected in supernatants from recombinant virus-infected cells, but not in recombinants with truncated 147 amino acids from the termination codon, and intact NcSRS2 gene (401 amino acids). By flow cytometric and confocal laser scanning microscopic analyses, the truncation of the hydrophobic C-terminal tail in NcSRS2 was shown to result in the reduction of protein expression on the cell surface relative to intact rNcSRS2. Except for the recombinant lacking the 147 C-terminal residues, three other rNcSRS2 were detected in the supernatants after treatment with phosphatidylinositol-specific phospholipase C. Our results demonstrate that the N. caninum NcSRS2 is a transmembrane protein that contains a glycosylphosphatidylinositol-anchor molecule in insect cells, and that the hydrophobic C-terminal domain is an essential component for GPI-membrane attachment. We have likewise shown the usefulness of the insect-recombinant baculovirus system in the expression of rNcSRS2.  相似文献   

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