目的:制备粉尘螨变应原第27组分(Der f 27)重组蛋白,鉴定其免疫活性。方法:构建pET-28a(+)-Der f 27质粒,转化至E.coli BL21(DE3)感受态细胞,经诱导表达和纯化后,获得重组变应原rDer f 27。IgE-ELISA和IgE-Western blot检测rDer f 27与...目的:制备粉尘螨变应原第27组分(Der f 27)重组蛋白,鉴定其免疫活性。方法:构建pET-28a(+)-Der f 27质粒,转化至E.coli BL21(DE3)感受态细胞,经诱导表达和纯化后,获得重组变应原rDer f 27。IgE-ELISA和IgE-Western blot检测rDer f 27与粉尘螨变应性鼻炎患者血清IgE结合率,分别将变应性鼻炎患者PBMC、人支气管上皮细胞BESA-2B与rDer f 27共孵育24 h后测定细胞因子表达;生物信息学软件分析Der f 27的理化性质和结构。结果:成功构建pET-28a(+)-Der f 27质粒并转化至BL21(DE3)细胞,经IPTG诱导表达和纯化后,SDS-PAGE和Western blot在约48 kD处见特异性条带;IgE-ELISA和IgEWestern blot检测rDer f 27与粉尘螨变应性鼻炎患者血清IgE结合率分别为39.5%和45.5%;与对照组相比,变应性鼻炎患者PBMC与rDer f 27共孵育后,IL-6和IL-8表达升高(P<0.05);BESA-2B细胞与rDer f 27共孵育后,IL-10和TGF-β表达降低,IL-17A和IL-23A表达升高(P<0.05);生物信息学结果显示Der f 27属于丝氨酸蛋白酶抑制物家族,具有此家族通用结构及功能,二级结构主要为α螺旋(42.62%)和无规则卷曲(35.60%)。结论:成功制备了具有较好免疫反应性和免疫原性的重组变应原rDer f 27,并揭示其为变应性鼻炎的重要变应原之一。展开更多
从高温土壤中分离得到的一株产耐热中性蛋白酶的嗜热芽孢杆菌,该菌分泌的胞外蛋白酶粗酶液经80%饱和度硫酸铵沉淀、DEAE-Sepharose Fast Flow阴离子交换层析和Superdax75凝胶层析分离纯化后,纯化倍数提高4．36倍,得率为5．3%,经SDS-PAG...从高温土壤中分离得到的一株产耐热中性蛋白酶的嗜热芽孢杆菌,该菌分泌的胞外蛋白酶粗酶液经80%饱和度硫酸铵沉淀、DEAE-Sepharose Fast Flow阴离子交换层析和Superdax75凝胶层析分离纯化后,纯化倍数提高4．36倍,得率为5．3%,经SDS-PAGE电泳测得其分子量为30．6kDa。酶的最适温度与pH实验表明,该酶最适温度为65℃、最适pH为7．5,并且该酶在50℃时表现出1h以上的稳定性。该蛋白酶的活性受到丝氨酸族蛋白酶专一性抑制PMSF和金属离子螯合剂EDTA强烈抑制,Zn^(2+)能提高酶活性,因此该蛋白酶为Zn^(2+)激活的丝氨酸族蛋白酶。展开更多
Lumbrukinase gene from earthworm ( L.bimastus ) was obtained by RT\|PCR. The product, PI 239 , was sequenced and analyzed by biology programs and database. The gene including signal peptide coding sequence was cloned ...Lumbrukinase gene from earthworm ( L.bimastus ) was obtained by RT\|PCR. The product, PI 239 , was sequenced and analyzed by biology programs and database. The gene including signal peptide coding sequence was cloned into an eukaryotic vector and the clones were obtained by transferring into BHK cells. The gene was fused with EGFP gene at C\|terminal to be detected conveniently by its fluorescence. The lumbrukinase gene PI 239 has 852 nucleotides that code for 239 amino acid residues as mature peptide chain. The N terminal of PI 239 shares certain homology with those known lumbrukinase. The enzyme contains relative more acidic amino acid residues, and has homology to serine protease. It belongs to the acidic protein, serine protease. Conformation prediction indicates that its secondary structure mainly consists of β sheet. It has two super secondary structure motifs with the active sites Asp188 and Ser189 in between. The DNA and mRNA of the whole gene could be detected in BHK clones, but no recombinant protein detected. Under cofocal microscope, the cells transferred with fused gene showed fluorescence indicating that the fused protein was expressed. In addition, the cells containing the fused gene died soon while most of the control cells were still alive. It seemed that the protein could be expressed in BHK cells as a cytotoxin, though at a low level.展开更多
文摘目的:制备粉尘螨变应原第27组分(Der f 27)重组蛋白,鉴定其免疫活性。方法:构建pET-28a(+)-Der f 27质粒,转化至E.coli BL21(DE3)感受态细胞,经诱导表达和纯化后,获得重组变应原rDer f 27。IgE-ELISA和IgE-Western blot检测rDer f 27与粉尘螨变应性鼻炎患者血清IgE结合率,分别将变应性鼻炎患者PBMC、人支气管上皮细胞BESA-2B与rDer f 27共孵育24 h后测定细胞因子表达;生物信息学软件分析Der f 27的理化性质和结构。结果:成功构建pET-28a(+)-Der f 27质粒并转化至BL21(DE3)细胞,经IPTG诱导表达和纯化后,SDS-PAGE和Western blot在约48 kD处见特异性条带;IgE-ELISA和IgEWestern blot检测rDer f 27与粉尘螨变应性鼻炎患者血清IgE结合率分别为39.5%和45.5%;与对照组相比,变应性鼻炎患者PBMC与rDer f 27共孵育后,IL-6和IL-8表达升高(P<0.05);BESA-2B细胞与rDer f 27共孵育后,IL-10和TGF-β表达降低,IL-17A和IL-23A表达升高(P<0.05);生物信息学结果显示Der f 27属于丝氨酸蛋白酶抑制物家族,具有此家族通用结构及功能,二级结构主要为α螺旋(42.62%)和无规则卷曲(35.60%)。结论:成功制备了具有较好免疫反应性和免疫原性的重组变应原rDer f 27,并揭示其为变应性鼻炎的重要变应原之一。
文摘从高温土壤中分离得到的一株产耐热中性蛋白酶的嗜热芽孢杆菌,该菌分泌的胞外蛋白酶粗酶液经80%饱和度硫酸铵沉淀、DEAE-Sepharose Fast Flow阴离子交换层析和Superdax75凝胶层析分离纯化后,纯化倍数提高4．36倍,得率为5．3%,经SDS-PAGE电泳测得其分子量为30．6kDa。酶的最适温度与pH实验表明,该酶最适温度为65℃、最适pH为7．5,并且该酶在50℃时表现出1h以上的稳定性。该蛋白酶的活性受到丝氨酸族蛋白酶专一性抑制PMSF和金属离子螯合剂EDTA强烈抑制,Zn^(2+)能提高酶活性,因此该蛋白酶为Zn^(2+)激活的丝氨酸族蛋白酶。
文摘Lumbrukinase gene from earthworm ( L.bimastus ) was obtained by RT\|PCR. The product, PI 239 , was sequenced and analyzed by biology programs and database. The gene including signal peptide coding sequence was cloned into an eukaryotic vector and the clones were obtained by transferring into BHK cells. The gene was fused with EGFP gene at C\|terminal to be detected conveniently by its fluorescence. The lumbrukinase gene PI 239 has 852 nucleotides that code for 239 amino acid residues as mature peptide chain. The N terminal of PI 239 shares certain homology with those known lumbrukinase. The enzyme contains relative more acidic amino acid residues, and has homology to serine protease. It belongs to the acidic protein, serine protease. Conformation prediction indicates that its secondary structure mainly consists of β sheet. It has two super secondary structure motifs with the active sites Asp188 and Ser189 in between. The DNA and mRNA of the whole gene could be detected in BHK clones, but no recombinant protein detected. Under cofocal microscope, the cells transferred with fused gene showed fluorescence indicating that the fused protein was expressed. In addition, the cells containing the fused gene died soon while most of the control cells were still alive. It seemed that the protein could be expressed in BHK cells as a cytotoxin, though at a low level.
