日本血吸虫26kD抗原基因在BCG中的表达

研究了外源基因日本血吸虫２６ｋＤ抗原（Ｓｊ２６ＧＳＴ）在卡介苗（ｂａｃｉｌｕｓＣａｌｍｅｔｅ－Ｇｕｅｒｉｎ,ＢＣＧ）、耻垢分枝杆菌（Ｍ．ｓｍｅｇｍａｔｉｓ）和大肠杆菌（Ｅ．ｃｏｌｉ）中的表达．运用重组ＤＮＡ和聚合酶链反应（ＰＣＲ）等分子生物学技术,以表达Ｓｊ２６ＧＳＴ的Ｅ．ｃｏｌｉｐＧＥＸ衍生质粒为模板,经ＰＣＲ得到编码Ｓｊ２６ＧＳＴ的全长ｃＤＮＡ片段．将其按正确的阅读框顺序,克隆到人结核杆菌热休克蛋白（ｈｅａｔｓｈｏｃｋｐｒｏｔｅｉｎ,ＨＳＰ）７０的启动子下游,再将ＨＳＰ７０启动子和Ｓｊ２６ＧＳＴ基因一起亚克隆到Ｅ．ｃｏｌｉ－分枝杆菌穿梭质粒ｐＢＣＧ－２０００中,得到Ｅ．ｃｏｌｉ－分枝杆菌穿梭表达质粒ｐＢＣＧ－Ｓｊ２６．ｐＢＣＧ－Ｓｊ２６电转化入ＢＣＧ和Ｍ．ｓｍｅｇｍａｔｉｓｍｃ２１５５中表达Ｓｊ２６ＧＳＴ抗原,所表达的天然重组Ｓｊ２６ＧＳＴ（ｒＳｊ２６ＧＳＴ）为可溶性蛋白,在ＳＤＳ－ＰＡＧＥ上分子量为２６ｋＤ处可见明显的表达蛋白带．其表达量分别占ＢＣＧ和Ｍ．ｓｍｅｇｍａｔｉｓ菌体总蛋白的１５％和１０％．可见,Ｓｊ２６ＧＳＴ基因能在ＢＣＧ中高效表达．     

雄激素受体融合蛋白的表达及其多克隆抗体的制备与纯化

将雄激素受体的ｃＤＮＡ片段克隆到表达质粒ｐＧＥＸ－３Ｘ内,在Ｅ．ｃｏｌｉ中表达,得到可溶性表达产物ＧＳＴ－ＡＲ。用该融合蛋白制得的兔多克隆抗体,经ＧＳＴ－Ｓｅｐｈａｒｏｓｅ－４Ｂ亲和吸附纯化后,表现出较好的抗ＡＲ的专一性,可用于ＡＲ结构和功能的研究。     

重组人尿激酶原的分离纯化及性质研究

本文报道从人尿激酶原（ｐｒｏ－ｕｒｏｋｉｎａｓｅ,ｐｒｏ－ＵＫ）基因重组工程菌Ｅ．ｃｏｌｉＪＡ２２１表达产物的复性液中纯化尿激酶原的方法。复性产物经Ｚｎ＾２＋选择性沉淀,尿激酶抗体亲和柱层析,ｂｅｎｚａｍｉｄｉｎｅ－Ｓｅｐｈａｒｏｓｅ ＣＬ ４Ｂ亲和吸附,即得比活达１１００００ＩＵ／ｍｇ的纯化产品。样品经ＳＤＳ－ＰＡＧＥ鉴定,在还原及非还原条件下,均表现为分子量为４３ｋｄ的单一条带。动力学研究测得     

重组人融合基因Nm23—H1／HbFGF的构建及其在大肠杆菌中表达？…

根据Ｎｍ２３－Ｈ１与ＨｂＦＧＦｃＤＮＡ序列,人工合成一段中间核酸序列,将它分别与Ｎｍ２３－Ｈ１ｃＤＮＡ的上游引物及ＨｂＦＧＦｃＤＮＡ的下游引物组成两对引物,通过ＰＣＲ（聚合酶链式反应）构建出融合基因Ｎｍ２３－Ｈ１／ＨｂＦＧＦ,将其定向克隆于质粒载体ｐＢＶ２２０上,经诱导,ＳＤＳ－ＰＡＧＥ分析,表达产物分子量为３４ｋＤ,表达量占菌体总蛋白的１４％,表达产物以包涵体形式存在,ＥＬＩＳＡ和Ｗｅｓｔｅｒｎ     

HIV—1 p24蛋白在大肠肝菌中的高效可溶性表达,一步纯化抗原性分析

合成引物扩增ＨＩＶ－１ ｐ２４基因,并将其克隆到ｐＱＥ－３０质粒中,使其在大肠杆菌Ｅ．ｃｏｌｉ Ｍ１５中以ＩＰＴＧＨ诱导高效它ＳＤＳ－ＰＡＧＥ分析,该表达产物约占菌体总蛋白２０％,并且以可溶蛋白的形式存在于细菌裂解液上清之中。经镍离子柱亲和层一步纯化,洗脱产物中ｐ２４蛋白纯度达９５％。ＥＬＩＳＡ分析表明,该蛋白可与ＨＩＶ感染者血肖发生物异改正 免疫反应。以此蛋白交联Ｓｅｐｈａｒｏｓｅ ４Ｂ,新和层     

东亚钳蝎神经毒素在大肠杆菌中的表达

以山西风陵渡东亚钳蝎（ＢｕｔｈｕｓｍａｒｔｅｎｓｉＫａｒｓｃｈ）的尾腺总ＲＮＡ为模板,根据已知的蝎神经毒素保守氨基酸序列设计引物,利用ＰＣＲ技术,扩增并克隆了两个蝎神经毒素基因．序列分析表明,由两个基因导出的氨基酸序列（ＢｍＫＭｍ１和ＢｍＫＭｍ２）与已知的蝎神经毒素ＢｍＫⅠ、ＢｍＫⅡ、ＢｍＫⅢ、ＢｍＫＭ１、ＢｍＫＭ９有很高的同源性．将ＢｍＫＭｍ２基因重组到大肠杆菌分泌型表达载体ｐＥｘＳｅｃ１中进行表达．ＳＤＳ－ＰＡＧＥ证明表达产物被分泌到细胞周间质及培养液中．经ＩｇＧ－Ｓｅｐｈａｒｏｓｅ纯化后的蛋白质注射小白鼠表明表达产物有生物学活性     

粒细胞—巨噬细胞集落刺激因子／白细胞介素—3融合蛋白的表达研究

利用ＰＣＲ扩增得到粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）、白细胞介素－３（ＩＬ－３）完整基因片段,将其分别克隆ｐＧＥＭ－Ｔ构建成ＧＭ－ＣＳＦ／ＩＬ－３融合蛋白基因,ＤＮＡ序列与设计预期一致。将得到的融合蛋白基因克隆对７２ＲＮＡ聚合酶表达载体ｐＴ７ｚｚ,得到表达质粒ｐＦｕ,经转化至表达宿主Ｅ．ｃｏｌｉ ＢＬ２１（ＤＥ３）,在ＩＰＴＧ诱导下获得融合蛋白目的产物的直接表达。经ＳＤＳ－ＰＡＧＥ电泳鉴     

人表皮生长因子(EGF)与单核-巨噬细胞集落刺激因子(GM-CSF)融合蛋白在大肠杆菌中的表达

应用基因工程技术,将ＥＧＦ、ＧＭ－ＣＳＦ基因克隆到ｐＧＥＭ－３Ｚｆ（＋）载体的ＥｃｏＲＩ,ＢａｍＨＩ位点上,再将重组融合基因亚克隆到表达载体ｐＢＶ２２０的ＥｃｏＲＩ,ＢａｍＨＩ位点上,在大肠杆菌ＤＨ５α中进行表达,ＳＤＳ－聚丙烯酰胺凝胶电泳和Ｗｅｓｔｅｒｎｂｌｏｔ表明ＥＧＦ－ＧＭ－ＣＳＦ融合蛋白获得表达,并且具有ＥＧＦ、ＧＭ－ＣＳＦ的免疫学活性．这为进一步研究该融合蛋白的功能和肿瘤治疗提供一种新的基因产品．     

T7 启动子作用下人尿激酶原 cDNA 在大肠杆菌中的高效表达及分离纯化

化学合成的人尿激酶原ｃＤＮＡ克隆在表达质粒ｐＥＴ－１１ｄ中,在Ｔ７启动子的作用下,经０．１ｍｍｏｌ／Ｌ ＩＰＴＧ诱导,在大肠杆菌ＢＬ２１（ＤＥ３）ｐＬｙｓＳ中获得表达。其表达量占菌体总蛋白的１５％,表达产物以无活性的包涵体形式存在。经体外变复性,Ｚｎ＾２＋选择性沉淀,抗体亲和柱层析,及Ｂｅｎｚａｍｉｄｉｎｅ亲和吸附,所表达的人尿激酶原被纯化为单一条带,其比活约１１００００ＩＵ／ｍｇ。     

EB病毒DNA聚合酶基因的表达与纯化鼻咽癌病人诊断中的应用

以Ｅｐｓｔｅｉｎ－Ｂａｒｒ病毒（ＥＢＶ）ＤＮＡ聚合酶为抗原,建立了简便、快速、敏感和特异的鼻咽癌诊断方法。构建原表达载体ｐＲＳＥＴ－ＤＮＡ聚合酶及其亚克隆ＰＲＳＥＴ－Ａ１和ＢＬ２１（ＤＥ３）中表达的产物,经Ｗｅｓｔｅｒｎ－ｂｌｏｔ检测其抗原性并用于检测鼻咽癌（ｎａｓｏｐｈａｒｙｎｇｅａｌ ｃａｒｃｉｎｏｍａ,ＮＰＣ）病人血清中的抗体。在ＤＰＣ病人血清中存在抗ＥＢ病毒ＤＮＡ聚合酶的ＩｇＧ抗体,并证明     

日本血吸虫Sj Cyclophilin B基因的克隆、表达及免疫保护效果分析

本研究克隆和表达了日本血吸虫Cyclophilin B(Sj CyPB)编码基因的cDNA,分析其在日本血吸虫不同发育阶段虫体的表达情况,评估该重组抗原在小鼠体内诱导的抗血吸虫免疫保护效果。本研究以日本血吸虫童虫cDNA为模板,RT-PCR扩增其基因全长cDNA,提交序列到NCBI,登录号为GQ403665。荧光实时定量PCR分析该基因在日本血吸虫不同发育阶段虫体的表达情况,构建重组表达质粒,表达纯化重组蛋白。利用Western blotting检测重组蛋白的抗原性。以重组抗原免疫小鼠,评估其对小鼠诱导的免疫保护效果。结果表明,RT-PCR获得了Sj CyPB编码基因的全长cDNA,其开放阅读框为672bp。经分析确定其为CyPs家族中的CyPB基因,命名为Sj CyPB。荧光实时定量PCR分析表明,该基因在18d童虫期表达量最高,32d次之。构建了重组表达质粒pGEX-6P-1-SjCyPB,并在大肠杆菌中成功表达,表达产物分子量为49.5kDa。Western blotting试验显示该重组蛋白具有良好的抗原性,在小鼠免疫试验中,与空白对照组比较,免疫组小鼠获得31.5%的减虫率和41.01%的肝脏减卵率。本研究获得了日本血吸虫童虫期高表达的Sj CyPB基因的全长cDNA,成功构建了Sj CyPB原核重组表达质粒,并在大肠杆菌中成功表达,证实该重组抗原在小鼠体内诱导产生了部分免疫保护效果。     

人重组PSP及其生物活性研究

为了获得人重组 persephin( PSP)并研究其生物学活性 ,从人胎脑组织中提取总 RNA,以RT- PCR方法获取编码人 PSP成熟蛋白 c DNA.将人 PSP c DNA插入含 T7启动子的质粒 p ET-2 8a( + ) ,构建表达质粒 p ET- PSP,转化大肠杆菌 BL 2 1 ( DE3)获得表达菌株 BLPSP,经 IPTG诱导表达的 PSP形成包含体 .凝胶自动扫描分析表明 ,PSP表达量约占菌体总蛋白 2 0 %以上 .用Ni2 + - NTA树脂一步法纯化目的蛋白 ,纯度达 85%以上 .纯化和复性的 PSP蛋白能显著促进脊髓神经元的存活 .     

Receptor-Mediated Transcytosis of Cyclophilin B Through the Blood—Brain Barrier

Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein mainly located in intracellular vesicles and secreted in biological fluids. In previous works, we demonstrated that CyPB interacts with T lymphocytes and enhances in vitro cellular incorporation and activity of CsA. In addition to its immunosuppressive activity, CsA is able to promote regeneration of damaged peripheral nerves. However, the crossing of the drug from plasma to neural tissue is restricted by the relative impermeability of the blood-brain barrier. To know whether CyPB might also participate in the delivery of CsA into the brain, we have analyzed the interactions of CyPB with brain capillary endothelial cells. First, we demonstrated that CyPB binds to two types of binding sites present at the surface of capillary endothelial cells from various species of tissues. The first type of binding sites (K(D) = 300 nM; number of sites = 3 x 10(6)) is related to interactions with negatively charged compounds such as proteoglycans. The second type of binding sites, approximately 50,000 per cell, exhibits a higher affinity for CyPB (K(D) = 15 nM) and is involved in an endocytosis process, indicating it might correspond to a functional receptor. Finally, the use of an in vitro model of blood-brain barrier allowed us to demonstrate that CyPB is transcytosed by a receptor-mediated pathway (flux = 16.5 fmol/cm2/h). In these conditions, CyPB did not significantly modify the passage of CsA, indicating that it is unlikely to provide a pathway for CsA brain delivery.     

CD147 is a signaling receptor for cyclophilin B.

Cyclophilins A and B (CyPA and CyPB) are cyclosporin A binding proteins that can be secreted in response to inflammatory stimuli. We recently identified CD147 as a cell-surface receptor for CyPA and demonstrated that CD147 is an essential component in the CyPA-initiated signaling cascade that culminates in ERK activation and chemotaxis. Here we demonstrate that CD147 also serves as a receptor for CyPB. CyPB induced Ca(2+) flux and chemotaxis of CD147-transfected, but not control, CHO cells, and the chemotactic response of primary human neutrophils to CyPB was blocked by antibodies to CD147. These results suggest that CD147 serves as a receptor for extracellular cyclophilins.     

Cyclophilin B induces integrin-mediated cell adhesion by a mechanism involving CD98-dependent activation of protein kinase C-delta and p44/42 mitogen-activated protein kinases

Initially identified as a cyclosporin-A binding protein, cyclophilin B (CyPB) is an inflammatory mediator that induces adhesion of T lymphocytes to fibronectin, by a mechanism dependent on CD147 and alpha 4 beta 1 integrins. Recent findings have suggested that another cell membrane protein, CD98, may cooperate with CD147 to regulate beta1 integrin functions. Based on these functional relationships, we examined the contribution of CD98 in the pro-adhesive activity of CyPB, by utilizing the responsive promonocyte cell line THP-1. We demonstrated that cross-linking CD98 with CD98-AHN-18 antibody mimicked the responses induced by CyPB, i.e. homotypic aggregation, integrin-mediated adhesion to fibronectin and activation of p44/42 MAPK. Consistent with previous data, immunoprecipitation confirmed the existence of a heterocomplex wherein CD147, CD98 and beta1 integrins were associated. We then demonstrated that CyPB-induced cell adhesion and p44/42 MAPK activation were dependent on the participation of phosphoinositide 3-kinase and subsequent activation of protein kinase C-delta. Finally, silencing the expression of CD98 by RNA interference potently reduced CyPB-induced cell responses, thus confirming the role of CD98 in the pro-adhesive activity of CyPB. Altogether, our results support a model whereby CyPB induces integrin-mediated adhesion via interaction with a multimolecular unit formed by the association between CD147, CD98 and beta1 integrins.     

Cloning,expression, and purification of mouse heparanase

Heparanase is an endoglucuronidase that plays an important role in tumor invasion and metastasis. A full-length heparanase gene was cloned from a mouse embryo cDNA library and determined to encode a protein of 535 amino acids that is 77% identical to human heparanase. The full-length mouse gene was stably expressed in NS0 myeloma cells. The recombinant mouse heparanase protein was purified to homogeneity from cell lysates by a combination of Con-A affinity chromatography, heparin affinity chromatography, and size exclusion chromatography. The purified protein consisted of a non-covalent heterodimer of 50- and 8-kDa polypeptides, similar to the human homolog. The protein was enzymatically active in assays using radiolabeled ECM and heparan sulfate as substrates. The maximum heparanase activity was observed at acidic conditions; however, significant activity was also detected at neutral pH. The enzymatic activity of mouse heparanase was blocked by known heparanase inhibitors.     

Receptor type I and type II binding regions and the peptidyl-prolyl isomerase site of cyclophilin B are required for enhancement of T-lymphocyte adhesion to fibronectin

Cyclophilin B (CyPB), a cyclosporin A (CsA) binding protein, interacts with two types of binding sites at the surface of T-lymphocytes. The type I sites correspond to functional receptors involved in endocytosis and the type II sites to sulfated glycosaminoglycans (GAGs). Mutational analysis of CyPB has revealed that W128, which is part of the CsA-binding pocket, is implicated in the binding to the functional type I receptors and that two amino acid clusters located in the N-terminus ensure the binding to GAGs. The peptidyl-prolyl isomerase activity of CyPB is not required for receptor binding. We have recently demonstrated that CyPB enhances adhesion of peripheral blood T-lymphocytes to fibronectin, a component of the extracellular matrix. We intended to identify additional amino acids involved in the binding of CyPB to its functional type I receptor and to determine regions responsible for the stimulation of peripheral blood T-lymphocyte adhesion. We determined that residues R76, G77, K132, D155, and D158 of the calcineurin (CN) interacting region were implicated in the recognition of type I receptor but not of GAGs. We also found that two different changes in the N-terminal extension that abated binding to GAGs prevented adhesion of peripheral blood T-lymphocytes to coated CyPB, whereas abbrogation of the PPIase activity had no effect. On the other hand, the adhesion of peripheral blood T-lymphocytes to coated fibronectin was not stimulated by CyPB mutants devoid of either type I receptor or GAGs binding activity or by mutants of the PPIase site. Altogether, the results demonstrate that different regions of CyPB are involved in peripheral blood T-lymphocyte activation and imply a novel important physiological function for peptidyl-prolyl isomerase activity.     

Identification of two forms of cyclophilin from the hard tick Haemaphysalis longicornis

We have shown here the identification and characterization of two cyclophilin, cyclophilin A (CyPA) and B (CyPB), from the ixodid tick, Haemaphysalis longicornis. Both CyPA and CyPB contain the conserved peptidyl-prolyl isomerase (PPIase) domain, with CyPA consisting of 188 amino acids and CyPB of 216 amino acids. CyPA and CyPB share 50–67% amino acid sequence identity with the cyclophilins of other organisms, and are found in multiple organs throughout the developmental stages of ixodid ticks. In addition, recombinant CyPA and CyPB exhibited PPIase activity that could be inhibited by the cyclic peptides cyclosporin A (CsA). Silencing of CyPA through RNA interference has led to a significant reduction in the body weight of engorged ticks and their failure to lay eggs, in contrast to CyPB whose silencing did not result in any detectable phenotypic changes. Our results indicate that CyPA represents the major cyclophilin protein in H. longicornis involved in blood ingestion, viability, and oocyte development. This is the first report of cyclophilin proteins from ixodid and argasid ticks.