Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生...Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生过敏原Ara h 2的间接双抗夹心化学发光酶免疫分析法,并对该方法的灵敏度、准确度、精密度和特异性进行评价。该方法的检出限为1.085 ng/mL,线性范围为3.12~200 ng/mL,添加回收率为78.30%~94.39%,批内和批间变异系数均小于10%,且特异性良好,与其他常见食物过敏原无交叉反应。该方法与相同抗体所建立的间接双抗夹心酶联免疫吸附测定(enzyme-linked immunosorbent assay, ELISA)方法相比,在灵敏度上表现出一定优势。该研究开发的化学发光酶免疫分析法可对花生食品生产过程中和消费前的Ara h 2过敏原成分检测提供可靠的技术支持。展开更多
Superoxide dismutase(SOD, EC 1.15.1.1) plays a key role in response to drought stress, and differences in SOD activity changes among cultivars are important under drought conditions. We obtained the full-length DNA of...Superoxide dismutase(SOD, EC 1.15.1.1) plays a key role in response to drought stress, and differences in SOD activity changes among cultivars are important under drought conditions. We obtained the full-length DNA of the chloroplast Cu/Zn-SOD gene(Ah CSD2)from 11 allotetraploid cultivars and 5 diploid wild species in peanut. BLAST search against the peanut genome showed that the Ah CSD2 genes g CSD2-1 and g CSD2-2 are located at the tops of chromosome A03(A genome) and B03(B genome), respectively, and both contain 8exons and 7 introns. Nucleotide sequence analyses indicated that g CSD2-2 sequences were identical among all the tested cultivars, while g CSD2-1 sequences showed allelic variations.The amino acid sequences deduced from g CSD2-1 and g CSD2-2 both contain a chloroplast transit peptide and are distinguished by 6 amino acid(aa) residue differences. The other 2aa residue variations in the mature peptide regions give rise to three-dimensional structure changes of the protein deduced from the genes g CSD2-1 and g CSD2-2. Sequences analyses of cultivars and wild species showed that g CSD2-2 of Arachis hypogaea and g Aip CSD2(Arachis ipaensis) are identical, and despite the abundant polymorphic loci between g CSD2-1 of A.hypogaea and sequences from A genome wild species, the deduced amino acid sequence of Ah CSD2-1(A. hypogaea) is identical to that of Adu CSD2(Arachis duranensis), whereas Aco CSD2(Arachis correntina) and Aca CSD2(Arachis cardenasii) both have 2 aa differences in the transit peptide region compared with Ah CSD2-1(A. hypogaea). Based on the Peanut Genome Project, promoter prediction revealed many stress-related cis-acting elements within the potential promoter regions(pp-A and pp-B). pp-A contains more binding sites for drought-associated transcriptional factors than pp-B. We hypothesize that the marked changes in SOD activity in different cultivars under drought stress are tightly regulated by transcription factors through transcription and expression of Ah CSD2 genes.展开更多
Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2) can be digested and cause allergic reactions. Making the allergens more resistant to digestion may aid in non-absorption and excretion ...Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2) can be digested and cause allergic reactions. Making the allergens more resistant to digestion may aid in non-absorption and excretion of the allergens. Our objectives were to make Ara h 1 and Ara h 2 more resistant to digestion and test them in a model system using trypsin as the digestive enzyme. The resistant allergens were prepared by covalently attaching p-aminobenzamidine (pABA), a protease inhibitor, to peanut allergens in an extract or on a PVDF membrane using glutaraldehyde, and were then tested for resistance to trypsin digestion. SDS-PAGE and Western blot were performed to determine the allergenic capacity of the modified allergens. A control was prepared using glycine instead. Results showed that Ara h 2, when covalently attached with pABA, was more resistant to trypin digestion than the native allergen. Similarly, Ara h 1, prepared on a PVDF membrane and treated with pABA, displayed a resistance to trypsin digestion. Treatment of the allergens with glycine (a control) instead of pABA showed that the modified allergens were as digestible as native allergens. Blot assays showed that the pABA-treated allergens exhibited a lower allergenic capacity than native allergens. It was concluded that pABA, when attached to peanut allergen Ara h 1 or Ara h 2, inhibited digestion of the allergen by trypsin and reduced their allergenic capacity as well.展开更多
构建经基因工程改造的Ara h 2表达载体,表达并纯化该蛋白,鉴定其过敏原性。将花生主要过敏原Arah 2基因序列进行颠换,并将颠换后的序列进行合成,再将合成后的基因克隆到原核表达载体pET-32a(+)上,然后转入Origami宿主表达菌中;利用Isopr...构建经基因工程改造的Ara h 2表达载体,表达并纯化该蛋白,鉴定其过敏原性。将花生主要过敏原Arah 2基因序列进行颠换,并将颠换后的序列进行合成,再将合成后的基因克隆到原核表达载体pET-32a(+)上,然后转入Origami宿主表达菌中;利用Isopropylβ-D-1-Thiogalactopyranoside(IPTG)诱导表达;通过Ni2+亲和层析纯化目的蛋白;Western blotting和ELISA鉴定该重组蛋白的过敏原性。测序结果表明合成后的序列成功整合到原核表达载体pET-32a(+)上。重组的目的蛋白纯化后经SDS-PAGE鉴定,蛋白大小与理论值相符。Western blotting和ELISA结果均表明经基因工程改造的Ara h 2(F-Ara h 2)蛋白与重组的Ara h 2(R-Ara h 2)蛋白相比,结合花生过敏患者混合血清中IgE显著降低。成功构建经基因工程改造的Ara h 2表达载体,初步的体外实验表明该基因表达的重组蛋白具有低致敏原性。展开更多
为探讨辐照处理对花生Ara h 2蛋白结构与致敏活性的影响,采用不同剂量^(60)Co-γ辐照处理分离纯化所得到的花生过敏原Ara h 2蛋白,结合紫外扫描光谱、圆二色谱(CD)和聚丙烯酰胺凝胶电泳(SDS-PAGE)评估辐照处理后Ara h 2蛋白的结构变化,...为探讨辐照处理对花生Ara h 2蛋白结构与致敏活性的影响,采用不同剂量^(60)Co-γ辐照处理分离纯化所得到的花生过敏原Ara h 2蛋白,结合紫外扫描光谱、圆二色谱(CD)和聚丙烯酰胺凝胶电泳(SDS-PAGE)评估辐照处理后Ara h 2蛋白的结构变化,并用免疫印迹法和间接酶联免疫吸附法检测辐照处理后Ara h 2的抗原性变化。结果表明,^(60)Co-γ辐照处理可以显著改变花生Ara h 2蛋白的构象,使其降解、发生交联。随着辐照剂量的增大,Ara h 2蛋白与抗体的结合能力呈逐渐下降趋势,且与蛋白紫外吸光度的增强和α-螺旋含量的降低呈现良好的相关性。当辐照剂量为10 kGy时,可基本破坏Ara h 2蛋白的结构和免疫活性。^(60)Co-γ辐照处理可以有效降低花生过敏原Ara h 2蛋白的致敏性,这为花生脱敏技术的研究提供了新思路。展开更多
文摘Ara h 2是花生主要过敏原之一,为开发食物中Ara h 2过敏原成分的快速检测方法,减少因误食导致花生过敏事件的发生,该研究采用鼠源单克隆抗体作为捕获抗体、兔源多克隆抗体作为检测抗体,通过棋盘法优化抗体工作浓度,建立了一种检测花生过敏原Ara h 2的间接双抗夹心化学发光酶免疫分析法,并对该方法的灵敏度、准确度、精密度和特异性进行评价。该方法的检出限为1.085 ng/mL,线性范围为3.12~200 ng/mL,添加回收率为78.30%~94.39%,批内和批间变异系数均小于10%,且特异性良好,与其他常见食物过敏原无交叉反应。该方法与相同抗体所建立的间接双抗夹心酶联免疫吸附测定(enzyme-linked immunosorbent assay, ELISA)方法相比,在灵敏度上表现出一定优势。该研究开发的化学发光酶免疫分析法可对花生食品生产过程中和消费前的Ara h 2过敏原成分检测提供可靠的技术支持。
基金financial support by the Natural Science Foundation of China (NSFC) (31201167)the earmarked fund for China Agriculture Research System (CARS-14)+1 种基金the Peanut Seed Industry Project in Shandong province of Chinathe earmarked fund for Agriculture Research System in Shandong province of China
文摘Superoxide dismutase(SOD, EC 1.15.1.1) plays a key role in response to drought stress, and differences in SOD activity changes among cultivars are important under drought conditions. We obtained the full-length DNA of the chloroplast Cu/Zn-SOD gene(Ah CSD2)from 11 allotetraploid cultivars and 5 diploid wild species in peanut. BLAST search against the peanut genome showed that the Ah CSD2 genes g CSD2-1 and g CSD2-2 are located at the tops of chromosome A03(A genome) and B03(B genome), respectively, and both contain 8exons and 7 introns. Nucleotide sequence analyses indicated that g CSD2-2 sequences were identical among all the tested cultivars, while g CSD2-1 sequences showed allelic variations.The amino acid sequences deduced from g CSD2-1 and g CSD2-2 both contain a chloroplast transit peptide and are distinguished by 6 amino acid(aa) residue differences. The other 2aa residue variations in the mature peptide regions give rise to three-dimensional structure changes of the protein deduced from the genes g CSD2-1 and g CSD2-2. Sequences analyses of cultivars and wild species showed that g CSD2-2 of Arachis hypogaea and g Aip CSD2(Arachis ipaensis) are identical, and despite the abundant polymorphic loci between g CSD2-1 of A.hypogaea and sequences from A genome wild species, the deduced amino acid sequence of Ah CSD2-1(A. hypogaea) is identical to that of Adu CSD2(Arachis duranensis), whereas Aco CSD2(Arachis correntina) and Aca CSD2(Arachis cardenasii) both have 2 aa differences in the transit peptide region compared with Ah CSD2-1(A. hypogaea). Based on the Peanut Genome Project, promoter prediction revealed many stress-related cis-acting elements within the potential promoter regions(pp-A and pp-B). pp-A contains more binding sites for drought-associated transcriptional factors than pp-B. We hypothesize that the marked changes in SOD activity in different cultivars under drought stress are tightly regulated by transcription factors through transcription and expression of Ah CSD2 genes.
文摘Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2) can be digested and cause allergic reactions. Making the allergens more resistant to digestion may aid in non-absorption and excretion of the allergens. Our objectives were to make Ara h 1 and Ara h 2 more resistant to digestion and test them in a model system using trypsin as the digestive enzyme. The resistant allergens were prepared by covalently attaching p-aminobenzamidine (pABA), a protease inhibitor, to peanut allergens in an extract or on a PVDF membrane using glutaraldehyde, and were then tested for resistance to trypsin digestion. SDS-PAGE and Western blot were performed to determine the allergenic capacity of the modified allergens. A control was prepared using glycine instead. Results showed that Ara h 2, when covalently attached with pABA, was more resistant to trypin digestion than the native allergen. Similarly, Ara h 1, prepared on a PVDF membrane and treated with pABA, displayed a resistance to trypsin digestion. Treatment of the allergens with glycine (a control) instead of pABA showed that the modified allergens were as digestible as native allergens. Blot assays showed that the pABA-treated allergens exhibited a lower allergenic capacity than native allergens. It was concluded that pABA, when attached to peanut allergen Ara h 1 or Ara h 2, inhibited digestion of the allergen by trypsin and reduced their allergenic capacity as well.
文摘构建经基因工程改造的Ara h 2表达载体,表达并纯化该蛋白,鉴定其过敏原性。将花生主要过敏原Arah 2基因序列进行颠换,并将颠换后的序列进行合成,再将合成后的基因克隆到原核表达载体pET-32a(+)上,然后转入Origami宿主表达菌中;利用Isopropylβ-D-1-Thiogalactopyranoside(IPTG)诱导表达;通过Ni2+亲和层析纯化目的蛋白;Western blotting和ELISA鉴定该重组蛋白的过敏原性。测序结果表明合成后的序列成功整合到原核表达载体pET-32a(+)上。重组的目的蛋白纯化后经SDS-PAGE鉴定,蛋白大小与理论值相符。Western blotting和ELISA结果均表明经基因工程改造的Ara h 2(F-Ara h 2)蛋白与重组的Ara h 2(R-Ara h 2)蛋白相比,结合花生过敏患者混合血清中IgE显著降低。成功构建经基因工程改造的Ara h 2表达载体,初步的体外实验表明该基因表达的重组蛋白具有低致敏原性。
文摘为探讨辐照处理对花生Ara h 2蛋白结构与致敏活性的影响,采用不同剂量^(60)Co-γ辐照处理分离纯化所得到的花生过敏原Ara h 2蛋白,结合紫外扫描光谱、圆二色谱(CD)和聚丙烯酰胺凝胶电泳(SDS-PAGE)评估辐照处理后Ara h 2蛋白的结构变化,并用免疫印迹法和间接酶联免疫吸附法检测辐照处理后Ara h 2的抗原性变化。结果表明,^(60)Co-γ辐照处理可以显著改变花生Ara h 2蛋白的构象,使其降解、发生交联。随着辐照剂量的增大,Ara h 2蛋白与抗体的结合能力呈逐渐下降趋势,且与蛋白紫外吸光度的增强和α-螺旋含量的降低呈现良好的相关性。当辐照剂量为10 kGy时,可基本破坏Ara h 2蛋白的结构和免疫活性。^(60)Co-γ辐照处理可以有效降低花生过敏原Ara h 2蛋白的致敏性,这为花生脱敏技术的研究提供了新思路。
