试验对以莆田黑猪精液为材料分离纯化得到的N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）进行了理化特性研究。经硫酸铵分级沉淀、DEAE Sepharose Fast Flow离子交换层析和Sephadex G100分子筛层析获得PAGE电泳纯化的NAGase酶制剂。以对硝基苯...试验对以莆田黑猪精液为材料分离纯化得到的N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）进行了理化特性研究。经硫酸铵分级沉淀、DEAE Sepharose Fast Flow离子交换层析和Sephadex G100分子筛层析获得PAGE电泳纯化的NAGase酶制剂。以对硝基苯-N-乙酰-β-D-氨基葡萄糖苷（pNP-GlcNAc）为底物,研究酶催化水解的相关性质。分离纯化获得的酶制剂比活力为1561.42U/mg,分子质量为58ku,只有1个亚基,等电点pI为9.13。酶的最适pH为5.6,最适温度为45℃,酶在pH3.6～7.8之间稳定,当pH〉8时迅速失活,在50℃以下处理30min酶活力保存稳定,高于50℃时,酶活力迅速降低。酶促反应动力学符合米氏双曲线方程,米氏常数Km为0.82mmol/L,最大反应速度Vm为39.23μmol/（L·min）。催化pNP-GlcNAc反应的活化能为27.30kJ/mol。金属离子中Na^＋、K^＋、Mg^2＋、Ca^2＋对酶活力无明显影响,Zn^2＋、Cu^2＋、Pb^2＋对酶有抑制作用。展开更多
Patients with acute infectious respiratory illness may emit bio‐aerosols containing pathogens to infect susceptible hosts,including other patients and healthcare workers.This study aimed to design the pediatric isola...Patients with acute infectious respiratory illness may emit bio‐aerosols containing pathogens to infect susceptible hosts,including other patients and healthcare workers.This study aimed to design the pediatric isolation(PI)bed and evaluate its purification effect on aerosols and microorganisms in the air in experiment rooms and verify the general wards'purification efficiency.The PI bed is connected to a purification device that surrounds the child's head to prevent contaminants'spread into the room.We test the purification effect of the PI bed in the experiment room and verified the purification effect of the PI bed in the hospital.The results showed that PI beds in the demonstration ward presented purifying effects on both smoke particulates and microorganisms like Staphylococcus albus(S.albus)and H1N1 virus.The Aerosol in the room in the hospital was then detected to validity the purification rate.Therefore,Isolation beds could be used in hospitals to reduce the risk of nosocomial infection to protect the health of doctors,patients,and visitors.展开更多
文摘以蝾螺内脏为材料,通过硫酸铵沉淀分级分离、SephadexG 200分子筛柱层析和两次DEAE SephadexA 50离子交换柱层析纯化,获得聚丙烯酰胺凝胶电泳单一纯的N 乙酰 β D 氨基葡萄糖苷酶酶制剂.纯酶的比活力为1448U·mg-1.酶的紫外特征吸收峰在275nm处,内源荧光发射峰在340nm处.以对 硝基苯 N 乙酰 β D 氨基葡萄糖为底物,研究酶催化底物水解的反应动力学,结果表明:酶的最适pH为4.5,最适温度为45℃.该酶在pH3.5～6.0区域较稳定,而在pH>7能很快失活;在40℃以下处理30min,酶活力保持稳定,高于40℃,酶稳定性较差,很快失活.酶促反应动力学符合米氏双曲线方程,测得米氏常数Km为3.13mmol·L-1,最大反应速度Vm为17.68μmol·L-1·min-1.
文摘试验对以莆田黑猪精液为材料分离纯化得到的N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）进行了理化特性研究。经硫酸铵分级沉淀、DEAE Sepharose Fast Flow离子交换层析和Sephadex G100分子筛层析获得PAGE电泳纯化的NAGase酶制剂。以对硝基苯-N-乙酰-β-D-氨基葡萄糖苷（pNP-GlcNAc）为底物,研究酶催化水解的相关性质。分离纯化获得的酶制剂比活力为1561.42U/mg,分子质量为58ku,只有1个亚基,等电点pI为9.13。酶的最适pH为5.6,最适温度为45℃,酶在pH3.6～7.8之间稳定,当pH〉8时迅速失活,在50℃以下处理30min酶活力保存稳定,高于50℃时,酶活力迅速降低。酶促反应动力学符合米氏双曲线方程,米氏常数Km为0.82mmol/L,最大反应速度Vm为39.23μmol/（L·min）。催化pNP-GlcNAc反应的活化能为27.30kJ/mol。金属离子中Na^＋、K^＋、Mg^2＋、Ca^2＋对酶活力无明显影响,Zn^2＋、Cu^2＋、Pb^2＋对酶有抑制作用。
基金supported by grants from the National Key Research and Development Program of China(2018YFC1200100,2018YFC1200103)Scientific Research Project of Guangdong Province Traditional Chinese Medicine Bureau(20201191)+4 种基金Innovative and Strong School Project of Guangdong Provincial Department of Education(2020KZDZX1122)Foshan Science and Technology Innovation Project(2020001000416)Nanhai District Talent Plan(201905290008)Emergency Projects of Guangzhou Laboratory of Breathing Diseases and Emergent Public Health Events(EKPG21‐13)Special Project on key scientific research of COVID‐19 prevention and control in Guangzhou(202008070003).
文摘Patients with acute infectious respiratory illness may emit bio‐aerosols containing pathogens to infect susceptible hosts,including other patients and healthcare workers.This study aimed to design the pediatric isolation(PI)bed and evaluate its purification effect on aerosols and microorganisms in the air in experiment rooms and verify the general wards'purification efficiency.The PI bed is connected to a purification device that surrounds the child's head to prevent contaminants'spread into the room.We test the purification effect of the PI bed in the experiment room and verified the purification effect of the PI bed in the hospital.The results showed that PI beds in the demonstration ward presented purifying effects on both smoke particulates and microorganisms like Staphylococcus albus(S.albus)and H1N1 virus.The Aerosol in the room in the hospital was then detected to validity the purification rate.Therefore,Isolation beds could be used in hospitals to reduce the risk of nosocomial infection to protect the health of doctors,patients,and visitors.
文摘采用十字交叉法测定CF17发酵液的抑菌谱,并通过离心、旋转蒸发浓缩、丙酮沉淀、固相萃取以及半制备高效液相色谱法对抑菌物质进行分离纯化和鉴定.结果表明,CF17发酵液对油茶炭疽病、油茶叶枯病、油茶软腐病、杉木炭疽病、核桃壳梭孢、降香黄檀炭疽病、檀香炭疽病等的病原菌均有抑菌效果.50%丙酮分离纯化效果优于乙醇沉淀法与乙酸乙酯沉淀法;在固相萃取中,活性物质主要集中在60%乙腈梯度洗柱样品中,最后经HPLC分离收集到一个有明显抑菌圈的样品.经质谱鉴定抑菌成分为Tetramycin A.
