An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the fre...An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the free base porphyrin and its Zn（Ⅱ） complex form were 2. 66 and 27.31 × 10^5 l,/mol at 20 ℃ respectively. The interactions of the free base porphyrin were further investigated at temperatures between 15 ℃ and 37 ℃, The thermodynamics parameters, changes in free energy, enthalpy and entropy, were -31.23, 22.92, 54.15 ld/mol respectively. The heat capacity change was -355.53 J · mol^-1·K^-1 The binding was driven by entropic contribution, and showed strong enthalpy-entropy compensation. It was governed primarily by hydrophobic forces.展开更多
We describe a two-step method that uses wheat germ agglutinin immobilized on Sepharose gel followed by immunoaffinity chromatography (IAC) to extract recombinant human erythropoietin and Darbepoetin from equine plasma...We describe a two-step method that uses wheat germ agglutinin immobilized on Sepharose gel followed by immunoaffinity chromatography (IAC) to extract recombinant human erythropoietin and Darbepoetin from equine plasma. Lectin affinity chromatography was shown to be an effective approach for isolating these epoetins from plasma and in combination with IAC;this method gave superior recovery when compared to the use of the latter technique alone. Moreover, due to the ease with which it can be scaled up, it is particularly well suited for pre-concentrating larger volumes of samples prior to IAC and this provides a facile way of improving the overall sensitivity with which these foreign proteins can be detected in equine plasma.展开更多
In order to refine the products of wheat germ agglutinin(WGA),several ion exchangers,such as D261,732,DEAE-cellulose-32 and CM-cellulose-32, have been used to removed proteins and pigments with different colors,such a...In order to refine the products of wheat germ agglutinin(WGA),several ion exchangers,such as D261,732,DEAE-cellulose-32 and CM-cellulose-32, have been used to removed proteins and pigments with different colors,such as brown,red,yellow,green and black,in the extracts of wheat germ.The WGA obtained from this procedure has higher hemagglutination activity than that available from sigma Co. The minimum hemagglutination dose of the purified WGA for an equal volume of a 2% type A red blood cells is 4μg/ml.WGA is a mixture of isolectins with different isoelectric points,5.9,6.2 and 6.8.Their molecular weight identified by SDS-polyacrylamide gel electrophoresis are 15,000 dalton,18,000 dalton and 35,000 dalton,respectively.展开更多
目的研究血清肝型碱性磷酸酶 (L - AL P)凝集素亲和层析用于原发性肝癌诊断的价值。方法用麦胚凝集素(WGA)分离血清骨型碱性磷酸酶 (B- AL P)和 L - AL P,再将 L - AL P进行蔓陀萝凝集素 (DSA)亲和层析 ,分离不同亲和力组分。结果正常...目的研究血清肝型碱性磷酸酶 (L - AL P)凝集素亲和层析用于原发性肝癌诊断的价值。方法用麦胚凝集素(WGA)分离血清骨型碱性磷酸酶 (B- AL P)和 L - AL P,再将 L - AL P进行蔓陀萝凝集素 (DSA)亲和层析 ,分离不同亲和力组分。结果正常人血清 L - AL P不与 DSA结合 ,在慢性肝炎及肝硬化患者血清中分离到 DSA弱结合组分 ,原发性肝癌患者血清出现了特有的 DSA强结合组分 ,6 4例原发性肝癌血清中阳性率为 92 .19% ,其中 14例原发性小肝癌 (癌结节小于 5 cm )有 78.5 7%的阳性率。结论 L - AL P的 DSA强结合组分为原发性肝癌特异性标志 ,L - AL展开更多
目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺...目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺法制备麦胚凝集素修饰苦参碱纳米粒,以碳二亚胺与N-羟基琥珀酰亚胺比例、麦胚凝集素加入量和孵化时间为影响因素,粒径、电位和修饰率为评价指标,通过均匀设计优化工艺。结果苦参碱纳米粒的最佳条件为聚乳酸-羟基乙酸共聚物与苦参碱比例0.594∶1,转速815 r/min,聚乙烯醇浓度为0.46%,平均粒径、电位、包封率和载药量分别为112.04 nm、-15.38 m V、90.05%和27.14%。其麦胚凝集素修饰产物的最佳条件为碳二亚胺与N-羟基琥珀酰亚胺比例2.8∶0.12,麦胚凝集素加入量3 mg,孵化时间14 h,平均粒径、电位和修饰率分别为474.7 nm、-5.2 m V和69.51%。结论该制备工艺可靠,所得苦参碱纳米粒及其麦胚凝集素修饰产物性质稳定。展开更多
文摘An optical biosensor with a stirred cuvette has been used to monitor the interaction of immobilized wheat germ agglutinin （WGA） with two water-soluble cationic porphyrins, The association constants （Ka） of the free base porphyrin and its Zn（Ⅱ） complex form were 2. 66 and 27.31 × 10^5 l,/mol at 20 ℃ respectively. The interactions of the free base porphyrin were further investigated at temperatures between 15 ℃ and 37 ℃, The thermodynamics parameters, changes in free energy, enthalpy and entropy, were -31.23, 22.92, 54.15 ld/mol respectively. The heat capacity change was -355.53 J · mol^-1·K^-1 The binding was driven by entropic contribution, and showed strong enthalpy-entropy compensation. It was governed primarily by hydrophobic forces.
文摘We describe a two-step method that uses wheat germ agglutinin immobilized on Sepharose gel followed by immunoaffinity chromatography (IAC) to extract recombinant human erythropoietin and Darbepoetin from equine plasma. Lectin affinity chromatography was shown to be an effective approach for isolating these epoetins from plasma and in combination with IAC;this method gave superior recovery when compared to the use of the latter technique alone. Moreover, due to the ease with which it can be scaled up, it is particularly well suited for pre-concentrating larger volumes of samples prior to IAC and this provides a facile way of improving the overall sensitivity with which these foreign proteins can be detected in equine plasma.
文摘In order to refine the products of wheat germ agglutinin(WGA),several ion exchangers,such as D261,732,DEAE-cellulose-32 and CM-cellulose-32, have been used to removed proteins and pigments with different colors,such as brown,red,yellow,green and black,in the extracts of wheat germ.The WGA obtained from this procedure has higher hemagglutination activity than that available from sigma Co. The minimum hemagglutination dose of the purified WGA for an equal volume of a 2% type A red blood cells is 4μg/ml.WGA is a mixture of isolectins with different isoelectric points,5.9,6.2 and 6.8.Their molecular weight identified by SDS-polyacrylamide gel electrophoresis are 15,000 dalton,18,000 dalton and 35,000 dalton,respectively.
文摘目的研究血清肝型碱性磷酸酶 (L - AL P)凝集素亲和层析用于原发性肝癌诊断的价值。方法用麦胚凝集素(WGA)分离血清骨型碱性磷酸酶 (B- AL P)和 L - AL P,再将 L - AL P进行蔓陀萝凝集素 (DSA)亲和层析 ,分离不同亲和力组分。结果正常人血清 L - AL P不与 DSA结合 ,在慢性肝炎及肝硬化患者血清中分离到 DSA弱结合组分 ,原发性肝癌患者血清出现了特有的 DSA强结合组分 ,6 4例原发性肝癌血清中阳性率为 92 .19% ,其中 14例原发性小肝癌 (癌结节小于 5 cm )有 78.5 7%的阳性率。结论 L - AL P的 DSA强结合组分为原发性肝癌特异性标志 ,L - AL
文摘目的制备苦参碱纳米粒及其麦胚凝集素修饰产物。方法复乳化-溶剂挥发法制备苦参碱纳米粒,以聚乳酸-羟基乙酸共聚物与苦参碱比例、转速和聚乙烯醇浓度为影响因素,粒径、电位、包封率和载药量为评价指标,通过星点设计优化工艺。碳二亚胺法制备麦胚凝集素修饰苦参碱纳米粒,以碳二亚胺与N-羟基琥珀酰亚胺比例、麦胚凝集素加入量和孵化时间为影响因素,粒径、电位和修饰率为评价指标,通过均匀设计优化工艺。结果苦参碱纳米粒的最佳条件为聚乳酸-羟基乙酸共聚物与苦参碱比例0.594∶1,转速815 r/min,聚乙烯醇浓度为0.46%,平均粒径、电位、包封率和载药量分别为112.04 nm、-15.38 m V、90.05%和27.14%。其麦胚凝集素修饰产物的最佳条件为碳二亚胺与N-羟基琥珀酰亚胺比例2.8∶0.12,麦胚凝集素加入量3 mg,孵化时间14 h,平均粒径、电位和修饰率分别为474.7 nm、-5.2 m V和69.51%。结论该制备工艺可靠,所得苦参碱纳米粒及其麦胚凝集素修饰产物性质稳定。
