漆酶与各种类型底物反应性能的微量热法研究

在厌氧条件下，用ＬＫＢ－２１０７Ｂａｔｃｈ微量热系统研究了在２９８．１５Ｋ０．１ｍｏｌ／Ｌ磷酸盐缓冲溶液（ｐＨ７．４）中漆树漆酶与５种底物的反应，测定了各反应的反应焓变△Ｈｍ米氏常数Ｋｍ，酶底复合过程的吉布斯自由能△Ｇ０复合物中电子转移速率常数ｋ２，以及漆病对各种底物的催化活性ＥＡ．讨论了相同的实验条件下，各种酶底复合物的稳定性，底物官能团及其位置对酶反应中的电子转移速率和非酶反应中自由基聚合形式     

Studies on the reaction between Laccase ando-methoxyphenol by microcalorimetry

The reaction between Laccase ando-methoxyphenol have been studied by LKB-2107 batch microcalorimetry system. Thermodynamic parameters Δ _r H _m , ΔG _o , ΔG _T ^≠ and kinetic parameters (K _m ,k ₂) have been determined. The process of the reaction has been analyzed from changes in energy by using the transition state theory. Two methods for enhancing catalytic power of Laccase are proposed. The results shown that formation of an enzyme-substrate complex is “anticatalytic”. The enter and sole source of catalytic power is the stabilization of transition state; reactant-state interactions are by nature inhibitory and only waste catalytic power. Supported by the National Natural Science Foundation of China Wang Tianzhi: born in 1968. Ph D     

Effect of surfactant on the catalyzed oxidation of 2,6-dimethylphenol by rhus vernicifera laccase

Rhus vernicifera laccase-catalyzed oxidation of 2,6-dimethylphenol (DMP) was studied in the presence of 12 surfactant (Sf). C₁₆H₃₃N⁺ (CH₃)₃ Br⁻ (CTAB) etc 5 cationic Sf and C₁₂H₂₃SO₄Na (SDS) etc 3 anionic Sf can promote the reaction in the different extent. The promotion of CTAB is the largest among them. The affected factors of the reaction—concentration of CTAB and DMP, pH, temperature, laccase quantity and reaction kinetics are inverstigated further. The nonionic Sf-Tween-20, Tween-60, Tween-80 and Triton X-100 have not promotion to the reaction. Ji Licai: born in 1945, Associate professor     

生命金属离子对漆酶催化活性的影响

以５,６二氯２,３二氰基氢醌为底物,在ｐＨ＝４．４０条件下,用分光光度法考察了１１种生命金属离子（Ｎａ＋、Ｋ＋、Ｃａ２＋、Ｍｇ２＋、Ｍｎ２＋、Ｆｅ２＋、Ｃｏ２＋、Ｃｕ２＋、Ｃｒ６＋、Ｎｉ２＋、Ｚｎ２＋）存在下的漆酶催化氧化反应,发现Ｆｅ２＋离子对漆酶的催化活性显示出抑制作用,探讨了其抑制特征、抑制位点和作用方式．结果表明,Ｆｅ２＋离子对漆酶催化活性抑制属竞争性抑制过程,Ｆｅ２＋离子的抑制作用是通过还原漆酶反应产物半醌自由基阴离子来完成的．Ｆｅ２＋离子漆酶复合物的解离常数（Ｋｉ）经测定为１７．５×１０－６ｍｏｌ·Ｌ－１．     

漆树漆酶的催化氧化作用Ⅺ原儿茶酸酯类的漆酶酶催氧化

用分光光度法对原儿茶酸甲酯、正丁酯、正辛酯底物在不同ｐＨ条件下的离解和漆酶催化氧化反应进行了考察，测定了它们在ｐＨ＝８．０时的反应速度常数．结果表明，不为漆酶所喜爱的亲水性底物（原儿茶酸），经过适当疏水化处理，可以有效地改善其反应性和提高漆酶的催化活性．ＥＳＲ结果证明，这些底物的漆酶催化反应都经历了半醌自由基阴离子阶段；酯基的存在不能保证底物顺利地氧化成相应邻醌，用二苯乙二胺只能捕获到少量羟基化的邻醌     

漆酶对共基质体系下吲哚的去除研究

网络参与是一种体制外民主参与的新形式,完善了公众参与的手段和渠道。但是,由于存在着非理性、道德缺失等诸多问题和局限性,对民主政治发展产生了一定的消极影响。为了使网络参与走上规范性和有效性辩证互动的发展轨道,伦理的引导和规约必不可少,应对网络参与进行认同与反思前提下的伦理省思,使其在道德规范与制度引导下保持理性限度,并在自由与自律的张力中对网民进行道德约束。     

Studies on reduced extent method for inhibited thermokinetics of enzyme-catalyzed reaction

The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distinguishing inhibition type was given and the methods for calculating kinetic parameters,K _M,K _i andv _m were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation ofo-dihydroxybenzene bym-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type,K _M=6.224×10⁻³ mol·L⁻¹,K _i=2.363×10⁻² mol·L⁻¹. Xiong Ya: born Sep. 1961, Ph. D. graduate student. Curent research interest is in biothermochemistry research Supported by the National Natural Science Foundation of China     

Study on the action of sodium selenite on the mitochondria metabolism of<Emphasis Type="Italic">Carassius auratus</Emphasis> hybrid carps liver by microcalorimetry

By using an LKB-2277 bioactivity monitor and ampoule method, the fundamental thermogenesis curves of the metabolic process of liver mitochondria fromCarassius auratus hybrid carps and the toxic effect of Na₂SeO₃ on it were studied at 28°C. From the thermogenesis curves, the thermokinetic equations were established under different condition. The kinetics show that Na₂SeO₃ has toxic action on the metabolism process ofCarassius auratus hybrid carps liver mitochondria. Foundation item: Supported by the National Science Foundation of China (29973030, 30170010 and 5020310), Chenguang Project of Wuhan and National Postdoctor Foundation of China Biography: Li Xi (1968-), female, Associate pofessor, research direction: biothermochemistry and biomaterials.     

Studies inin situ PCR detected by the BrdU antibody technique

Using the BrdU antibody technique followed by an immuno-chemical staining (BAT), the amplification of DNA fragments specific to human Y chromosome on cell specimen slides was efficiently detected. Whether direct BrdU incorporation into PCR products orin situ hybridization with PCR products on slides, the amplified target DNA fragments of specimen were visualized by BAT under the microscope. The availability of BAT and differences in the sensitivity and efficiency between BAT and dig-11-dUTP labeling in cellin situ PCR were discussed. Zhang Xiyuan: born in Oct. 1935, Professor, Current research interest in Cellular and Molecular Biology Supported by the National Natural Science Foundation of China     

Microcalorimetric study on the antibiotic activity of clarithromycin and erythromycin

By using LKB-2277 Bioactivity Monitoring System, the heat effect changes in the process of inhibitory action of clarithromycin and erythromycin onEscherichia coli at 37°C were determined. Quantitative analysis showed that relationship between antibiotic concentrationc and rate contantk ofEscherichia coli growth, and half inhibitory ratio concentration IC₅₀: clarithromycin:k=0. 030 03–1. 1736×10⁻³ c, 8. 45 mg ·L⁻¹; erythromycin:k=0.031 08–8.4657×10⁻⁴ c, 14. 45 mg·L⁻¹. As a result of the microcalorimetry experiments, it not only indicated that antibacterial activity of clarithromycin was stronger than that of erythromycin, but also reported the changeable features of thermodynamics of the bacterial cell in biological, biochemical and metabolic process under different drug action. Foundation item: Supported by Natinal Natural Science Fundation of China (29973030), Natural Science Fundation of Hubei Province (98J052) and Post-doctoral Science Fundation of China Biography, SHEN Xue-song (1956-), Associate professor Research direction: biothermochemistry.     

微量量热法研究酸度和金属离子对淀粉酶催化作用的影响

利用热活性检测仪测定了在不同酸度和有抑制剂时淀粉在淀粉酶催化作用下的热功率-时间曲线.根椐酶催化反应动力学理论和对比进度法对实验结果进行处理,确定了酶催化反应的最适酸度,得到了有抑制剂(Li+,K+)时酶催化反应的表现米凯利斯常数（K′m）和最大速率（Vmax）. 定量比较了金属离子对酶催化反应的抑制效果.     

The toxic effect of solubilizing excipients on <Emphasis Type="Italic">Tetrahymena thermophila</Emphasis> BF<Subscript>5</Subscript> growth investigated by microcalorimetry

The toxic effect of different solubilizing excipients on the growth and metabolism of Tetrahymena thermophila BF₅ (T.t.BF₅) at various concentrations was investigated by microcalorimetry. The thermogenic curves of T.t.BF₅ growth were determined at 28°C, and were evaluated by dynamic parameters. The results indicated that the values of growth rate constant (k), maximum power (P₁, P₂), peak time (T₁, T₂) and total quantity of heat (Q) varied for different excipients. There was a good linear relationship between k and concentrations (r>0.95, P<0.01). 5% inhibition concentration (IC₅) of poloxamer 188, Tween 80, PEG 600, PEG 400 and Tween 20 was 2.18, 1.07, 1.35, 0.58, and 0.045 mg/mL, respectively. After the principal component analysis (PCA), Q, k and P₁ could characterize the effect of these excipients on T.t.BF5 growth. Comprehensive evaluation indicated that compared with the control group, poloxamer 188 had the weakest toxicity and Tween 20 had the strongest toxicity.     

用GC法研究叔丁基氯的水解反应

研究用ＧＣ测定叔丁基氯水解反应的方法。该测定方法不需分离提纯，而是根据混合物中反应物叔丁基氯和生成物叔丁醇的不同保留时间以及不同峰面积，直接从ＧＣ图上就可算出ｔ－ＢｕＣｌ和ＢｕＯＨ的相对含量，进一步计算其反应速度常数和活化能。该测定方法操作简便，重现性好。     

An in-situ DRIFTS study in the reaction between NO x and soot on BaAl2O4

The interactions between NO, O2 and their mixture on BaAl2O4, as well as the reaction of NOx with soot in the presence of O2, have been investigated using Diffuse Reflectance Infrared Fourier Transform Spectroscopy （DRIFTS）. NO adsorption produces only nitrites species in the absence of O2. NO2 adsorption produces nitrates species besides nitrites species. The produced nitrites will further react with O2, Osurf^-. and Olattice^2- to form nitrates. The reaction of NOx with soot begins with the reaction of nitrates with soot oxygenated complex （C（O））, which is regarded as the key and rate determining step. A reaction pathway is proposed for the catalyzed reaction of NOx with soot in the presence of O2.     

两株氧化葡萄糖酸杆菌静息细胞的催化性能比较

【目的】氧化葡萄糖酸杆菌是一种严格好氧的革兰氏阴性菌,能够立体选择性氧化多种羟基化合物生成相应的醛、酮或酸。【方法】本文将比较两株氧化葡萄糖酸杆菌DSM 2003和621H的静息细胞对甘油、乙二醇及乙醇的催化能力,并研究了溶氧对催化反应的影响。【结果】两株氧化葡萄糖酸杆菌氧化甘油的能力较相似,溶氧对这两株菌的甘油催化能力都有较大影响;氧化葡萄糖酸杆菌DSM 2003能够将乙二醇几乎全部氧化为羟基乙酸,副产物少,而621H转化相同量的底物只生成较少量的羟基乙酸,副产物多。氧化葡萄糖酸杆菌621H生产乙酸的能力也很低。【结论】两株氧化葡萄糖酸杆菌催化甘油生成二羟基丙酮的能力相当,但在催化醇生成酸的反应中,氧化葡萄糖酸杆菌DSM 2003更具优势。     

Electrochemical redox of hemoglobin at poly(o-phenylenediamine) film modified electrodes or promoted byo-phenylenediamine

Electrochemical redox of hemoglobin at poly(o-phenylenediamine) coated glass carbon electrodes or at bare glass carbon electrodes promoted byo-phenylenediamine have been investigated. The electrochemical characters of poly(o-phenylenediamine) films have also been studied by using cyclic voltammetry and potential-step chronoamperometry as well as current-step chronocoulometry techniques. A possible catalyzing mechanism for hemoglobin is proposed. Supported by the National Natural Science Foundation of China Ye Baoxian Born in July 1958. Ph. D., Associate professor, precent communication address is College of Chemistry and Chemical Engineering, Zhengzhou University, Zhengzhou, 450052     

漆酶/木聚糖酶体系去除废新闻纸脱墨浆中胶黏物的研究

废纸浆因含有大量的细小组分和阴离子杂质,极大地影响了纸机网部的滤水性能和成纸质量。笔者应用漆酶处理废新闻纸脱墨浆,研究其去除胶黏物的效果。结果表明：漆酶/木聚糖酶体系（LXS）处理废纸脱墨浆,能有效去除浆料中胶黏物,尤其是漆酶/木聚糖酶体系处理后碱抽提（LXS+E）去除效果更佳。在酶用量为15 μmol/(min·g)时,LXS和LXS+E处理后与原浆相比,浆中胶黏物分别降低了51.91 %和68.43 %,减轻了后续工序除胶黏物的负荷,改善了浆料滤水性。当漆酶用量为15 μmol/(min·g)时,LXS和LXS+E处理浆与原浆相比,打浆度分别降低了15.22 %和28.26 %。此外通过这两种方法处理还能提高浆料的强度,而浆料得率却稍有下降。     

Interfacial reaction between the oxidized SiC particles and Al-Mg alloys

The interfacial reactions of oxidized SiC particles reinforced Al-Mg matrix composites were investigated by the field emission-scanning electron microscopy (FE-SEM), TEM and X-ray diffraction. It was found that the nanoscale MgO forms initially due to the interfacial reaction, then whether it reacts with molten Al continuously or not depends on the content of Mg in the matrix and its covering densification at the surface of particles. When there is not enough Mg in the matrix for the formation of dense MgO layer, MgO will transform into MgAl₂O₄ crystal owing to the continuous reaction with SiO₂ and molten Al. When dense MgO layer forms at the surface of the particles due to the affluence of Mg for the initial reaction, it will protect the inner SiC from the attack of molten Al. However, the reaction products of both MgO and MgAl₂O₄ are thermo-stable phases at the surface of the particles under high temperature. The results clarify the interfacial reaction route and they are of great value to the control of the interfacial reactions and their interfacial design of the composites.     

Effects of ubiquitin-proteasome pathway on mouse sperm capacitation, acrosome reaction and in vitro fertilization

Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody against ubiquitinated proteins—UCP1; the polyclonal antibody against ubiquitin—anti-Ub, and a special inhibitor against proteasome—ALLN. Furthermore, we treated the capacitated sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation and acrosome reaction, but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role in mouse in vitro fertilization.