胆盐水解酶(bile salt hydrolase,BSH)是由肠道菌群中部分微生物产生并且广泛分布于动物胃肠道中的一种胞内酶,具有优良的胆酸盐水解活性。该研究旨在克隆并原核表达植物乳植杆菌胆盐水解酶(Lactobacillus plantarumbile bile salt hydr...胆盐水解酶(bile salt hydrolase,BSH)是由肠道菌群中部分微生物产生并且广泛分布于动物胃肠道中的一种胞内酶,具有优良的胆酸盐水解活性。该研究旨在克隆并原核表达植物乳植杆菌胆盐水解酶(Lactobacillus plantarumbile bile salt hydrolase,LpBSH),系统研究其酶学特性和结构特征,为开发新型降脂酶制剂提供理论基础。通过基因工程技术构建重组LpBSH表达系统,测定其酶学性质并进行动力学分析。结合生物信息学方法,对LpBSH的三维结构、活性位点及底物结合口袋进行预测和分析。结果表明,原核表达的LpBSH在最适条件下活性为88.7 U/mL,显著高于野生型。重组LpBSH在pH为6.5时活性最高,并在pH_(4).5~6.5范围内保持较高活性;K+对LpBSH水解活性有轻微促进作用,而重金属离子普遍抑制活性;动力学分析显示,LpBSH催化反应符合Hill方程,表现出底物正协同效应;通过生物信息学分析LpBSH的氨基酸序列并预测其三维结构特征,研究了关于其氨基酸序列、活性位点、底物结合口袋及底物偏好性的关系。该研究为深入理解LpBSH的结构与功能关系及其在动物胆固醇代谢中的作用奠定了基础,并为LpBSH酶制剂的开发提供了科学依据。展开更多
By successive chromatography on CM-Sepharose CL-6B,Sephadex G-100,Heparin-Sepharose CL-6B, a phosphodiesterase (PDE, EC3.1.4.1) was isolated and purified from Guangxi cobra venom. The final preparation was 89 fold pur...By successive chromatography on CM-Sepharose CL-6B,Sephadex G-100,Heparin-Sepharose CL-6B, a phosphodiesterase (PDE, EC3.1.4.1) was isolated and purified from Guangxi cobra venom. The final preparation was 89 fold pure and had high specific activity. The enzyme showed a single band on SDS-PAGE and IEF. The PDE showed a molecular weight of 110 kD and pI of 7.4. The enzyme consists of 840 amino acid residues and has only a methionine as N-terminal amino acid residues. It was rich in asparagine, leucine and glutamine and poor in sulphur-containing amino acid. It contains 5.38% neutral sugars. It has no acute toxicity and has analgesia effect.展开更多
文摘胆盐水解酶(bile salt hydrolase,BSH)是由肠道菌群中部分微生物产生并且广泛分布于动物胃肠道中的一种胞内酶,具有优良的胆酸盐水解活性。该研究旨在克隆并原核表达植物乳植杆菌胆盐水解酶(Lactobacillus plantarumbile bile salt hydrolase,LpBSH),系统研究其酶学特性和结构特征,为开发新型降脂酶制剂提供理论基础。通过基因工程技术构建重组LpBSH表达系统,测定其酶学性质并进行动力学分析。结合生物信息学方法,对LpBSH的三维结构、活性位点及底物结合口袋进行预测和分析。结果表明,原核表达的LpBSH在最适条件下活性为88.7 U/mL,显著高于野生型。重组LpBSH在pH为6.5时活性最高,并在pH_(4).5~6.5范围内保持较高活性;K+对LpBSH水解活性有轻微促进作用,而重金属离子普遍抑制活性;动力学分析显示,LpBSH催化反应符合Hill方程,表现出底物正协同效应;通过生物信息学分析LpBSH的氨基酸序列并预测其三维结构特征,研究了关于其氨基酸序列、活性位点、底物结合口袋及底物偏好性的关系。该研究为深入理解LpBSH的结构与功能关系及其在动物胆固醇代谢中的作用奠定了基础,并为LpBSH酶制剂的开发提供了科学依据。
文摘By successive chromatography on CM-Sepharose CL-6B,Sephadex G-100,Heparin-Sepharose CL-6B, a phosphodiesterase (PDE, EC3.1.4.1) was isolated and purified from Guangxi cobra venom. The final preparation was 89 fold pure and had high specific activity. The enzyme showed a single band on SDS-PAGE and IEF. The PDE showed a molecular weight of 110 kD and pI of 7.4. The enzyme consists of 840 amino acid residues and has only a methionine as N-terminal amino acid residues. It was rich in asparagine, leucine and glutamine and poor in sulphur-containing amino acid. It contains 5.38% neutral sugars. It has no acute toxicity and has analgesia effect.
