一锅法合成去甲基麻黄素

以廉价底物苯甲醛、 丙酮酸和NH₄Cl为原料, 通过级联乙醛羟酸合成酶(ASAHⅠ)催化缩合反应和胺脱氢酶(BbAmDH)催化还原胺化反应, 构建了去甲基麻黄素的生物合成新途径. 通过优化分步法和一锅法的反应条件, 使苯甲醛转化率分别达到99%和83%. 采用一锅法, 利用底物补料策略, 有效解除了ASAHI的底物和产物抑制作用, 批次反应的苯甲醛浓度从40 mmol/L提高到100 mmol/L, 苯甲醛转化率从83%提高到90%, 苯甲醛的时空转化率提高了2.7倍.     

潜流人工湿地微生物脱氢酶活性的空间变化特征

人工湿地是利用介质、植物和微生物构成的复合系统来处理污水。湿地植物如芦苇,具有根系放氧的性能,可在局部区域形成微氧环境,有利于好氧微生物的生长。人工湿地中生物膜的微生物活性直接影响到系统的功效。针对寒冷地区季节性运行的人工湿地,研究了两级逆向垂直潜流人工湿地中微生物INT脱氢酶活性（DHA）的变化。结果表明,系统中0．15m深度较0．22m深度的微生物DHA高,可能的原因是由于根系活动和受大气复氧的影响。DHA受温度变化影响明显。系统启动初期,微生物DHA随气温升高而升高;系统运行后期,DHA随气温降低相应下降。同时,DHA受营养物水平影响,高营养对应着高活性。     

LD含量和LDH、ACP、ALP、TCHE活性在有氧运动影响下的变化

为了探讨有氧运动对人体在不同功能状态下血乳酸（LD）代谢和乳酸脱氢酶（LDH）、酸性磷酸酶（ACP）、碱性磷酸酶（ALP）、乙酰胆碱脂酶（TCHE）活性的影响，对12名业余长跑大学生和12名普通大学生进行了对比研究，结果发现：安静时，血清LD含量、LDH、ACP活性无组间差异，长跑组ALP活性低于对照组，而TCHE活性高于对照组（P＞0.05）；定量负荷后，长跑组血清LD含量明显低于对照组、LDH活性明显高于对照组（P＜0.05），ACP活性高于对照组、ALP活性低于对照组（P＞0.05），TCHE活性无组间差异；力竭性运动后，长跑组LD含量和LDH活性极明显高于对照组（P＜0.001），TCHE活性高于对照组（P＞0.05），ACP、ALP活性无组间差异，以上表明长跑运动对机体在运动状态下的血乳酸代谢和LDH活性有显著的影响，但对ACP、ALP、TCHE活性无明显作用。     

青海高校学生红细胞乳酸脱氢酶同工酶的初步研究

采用聚丙酰胺凝胶电泳,分析了世居高原的藏汉学生红细胞中的乳酸脱氢酶(LDH)同工酶酶谱及其M亚基的相对含量.结果表明:藏汉学生的红细胞乳酸脱氢酶(LDH)同工酶谱存在差异,汉族学生的LDH同工酶酶谱显示了LDH1、LDH2、LDH3、LDH4等四种同工酶带,而藏族学生只有LDH1、LDH2、LDH3;藏族学生的M亚基的相对含量(%)为29 86±0 0534(M±SD),汉族学生的M亚基相对含量(%)为30 89±0 0364(M±SD).     

循环伏安法对邻苯二酚的测定

将氧化石墨烯分散液及谷氨酸的混合液用循环伏安法修饰在玻碳电极上,制备出聚L-谷氨酸/石墨烯修饰电极.通过循环伏安法,对邻苯二酚在此修饰电极上的电化学行为进行研究.结果表明,在最佳优化的实验条件下,邻苯二酚在0.507 V处出现一对氧化还原峰,且浓度在2.00×10-6 mol/L～4.00×10-4 mol/L范围内表...     

Creation of biocatalysts with prescribed properties

Oxidoreductases are widely used in different branches of industry (particularly, in pharmaceutical) and analytical biotechnology. To optimize the use and to reduce production cost of a target product, the properties of a biocatalyst should be modified to meet requirements of a specific process or method of analysis. Problem of creation of biocatalysts with prescribed properties includes complex set of R&D such as an engineering of enzyme properties, construction of recombinant strains overproducing the target protein, development of a large-scale downstream process and preparation of a working form of a biocatalysts. In the present work, the basic features and practical examples of such an over-all approach are considered for formate dehydrogenase and D-amino acid oxidase. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1014–1022, May, 2008.     

Electrocatalytic detection of NADH and ethanol at glassy carbon electrode modified with electropolymerized films from methylene green

The oxidation of NADH on electropolymerizing methylene green (MG)-modified glassy carbon electrode (GCE) is described. The modified electrode shows an excellent electrocatalytic activity toward NADH oxidation, reducing its overpotential by about 650 mV and exhibits a wide linear range of 5.6–420 μM NADH with the detection limit of 3.8 μM. The electrode displays a good reproducibility and stability and the coexisting species does not affect the determination of NADH. The application in the amperometric biosensing of ethanol using alcohol dehydrogenase enzyme (ADH) also has been demonstrated with this electrode. MG-modified GCE can not only be used to detect NADH in biochemical reaction, but also can be used as the potential matrix of the construction of dehydrogenases biosensor.     

黑莓果实发育成熟期木质素合成CAD酶及其基因表达

【目的】比较黑莓高硬度品种‘Arapaho’和低硬度品种‘Boysen’果实发育成熟期木质素合成肉桂醇脱氢酶(CAD)基因表达,及其与CAD酶活性及总木质素含量的关系。【方法】对不同发育时期的黑莓果肉,利用半定量RT-PCR分析18个RuCADs基因成员的表达,利用比色法测定CAD酶活性,利用滴定法测定总木质素含量。【结果】在黑莓的18个RuCAD基因成员中,有8个CADs基因成员在2个品种发育早、中期果肉中表达量较高; 其中RuCAD16仅在‘Boysen’的早、中期果肉中表达,而在‘Arapaho’中不表达。‘Arapaho’和‘Boysen’果肉CAD酶活性均在着色前即花后9 d和花后21 d时最高,着色后呈下降趋势。‘Arapaho’和‘Boysen’果肉木质素分别在花后24 d和花后27 d含量较高。【结论】‘Arapaho’和‘Boysen’果实着色后,RuCADs基因成员表达呈多样化,且硬度与RuCAD酶及木质素含量关系表现出一定差异; 而在果实发育后期,RuCADs基因表达量降低。CAD酶活性降低及木质素含量下降,与黑莓成熟果实硬度下降具一致性,推测木质素合成与成熟果实硬度形成具有相关性。     

用吐温80—盐—水液—固萃取体系从兔肌中分离纯化乳酸脱氢酶

用吐温８０－盐－水液－固萃取体系从兔肌中分离纯化乳酸脱氢酶＊柳畅先邓江天雷锦桂游文淑李步海（中南民族学院化学系武汉４３００７４）关键词液－固萃取吐温８０乳酸脱氢酶中图分类号Ｏ６５８．２非有机溶剂液－固萃取体系是一种新的萃取体系，其特点之一是聚合物固相...     

Electron Communication Between Electrode and Dye-Linked L-Proline Dehydrogenase in Organized Layer-by-Layer Multilayer Film

Multilayer film was fabricated on an electrode surface by alternate layer-by-layer(LBL) adsorption of polycationic redox polymer(PEI-Fc) and dye-linked L-proline dehydrogenase(L-proDH).The electrochemistry of the PEI-Fc/L-proDH multilayer modified electrode was investigated by cyclic voltammetry,and the enzyme catalysis mediated by the redox polymer was studied in a solution containing L-proline.It was observed that electron communication between L-proDH and the electrode was achieved with the help of PEI-F...