量热法研究线粒体代谢的热力学和动力学行为

线粒体是细胞中极为重要的细胞器，是产生细胞所必需的“富能”物质ATP的重要场所，为细胞活动提供所需化学能．在生命体能量代谢过程中除一部分能量用于合成ATP外，其余则以热的形式释出．用精密热量计测出线粒体代谢过程中的热量输出对了解线粒体的功能和代谢机制具有十分重要的意义．用微量热法研究线粒体体外代谢已有一些报导［‘，’］．本工作用精密热量计和差式扫描量热仪侧定了水稻线粒体体外代谢热谱和DSC曲线，计算了水稻线粒体活性增长速率常数，比较了不同保藏时间的水稻线粒体体外代谢的差异，并初步探讨了水稻线粒体在变…     

线粒体体外代谢热动力学模型及其演化优化研究

导出了线粒体体外代谢的热动力学方程，探讨了它和指数模型的关系，将演化计算技术引入生物热化学领域，用ＭＴＤ方程和演化计算技术，对文献报导的八种鱼肝线粒体体外代谢的热动力学参数进行了全局优化。     

不同条件下离体大鼠肝脏线粒体能量代谢微量热分析

为了探究线粒体的能量代谢过程,本文以离体大鼠肝脏线粒体为模型,利用多通道、高灵敏度的热活性检测仪TAM Ⅲ,实时监测了不同线粒体浓度、不同底物、不同缓冲液、几种呼吸抑制剂以及Ca²⁺和线粒体渗透转换孔抑制剂CsA存在时线粒体的能量代谢,获得了完整的热功率―时间曲线,并通过计算得到了线粒体能量代谢的热动力学参数。通过分析发现：（1）线粒体浓度越大,代谢越快;（2）直接底物琥珀酸钠使线粒体代谢更快;（3）高浓度Ca²⁺能够刺激线粒体快速产热,且在长期代谢进程中,线粒体渗透转换孔抑制剂CsA并不能改变Ca²⁺造成的影响;（4）不同缓冲液对线粒体代谢的影响基于其组分的不同,缓冲液中含有呼吸底物;（5）呼吸抑制剂都能抑制线粒体的能量代谢,尤其是复合物IV的抑制剂NaN₃,高浓度下使代谢停止。     

线粒体体外代谢热动力学研究

线粒体是细胞重要的细胞器之一，有细胞的“能源工厂”之称．因为线粒体内有许多酶，是特殊的酶催化氧化反应的场所山；所有动、植物细胞的线粒体都能通过各种营养物的氧化而产生“富能”物质ATP．采用一定的技术可将线粒体从细胞中分离出来，分离出来的线粒体中的酶系统还有一定的活性，而且线粒体内也有一定的营养物质，这样酶系统就能利用这些营养物进行代谢，从而释放出一定的能量．我们用微量热法对两种鱼肝脏线粒体进行了测量，发现线粒体代谢过程分四个阶段：停滞期、活性恢复期、稳定期、活性衰减期．在活性恢复期和活性衰减期，…     

鱼肝线粒体代谢热与品种生长及杂交优势关系的微量热研究

采用LKB-2277生物活性检测系统测定了六个不同品种鱼的肝线粒体的代谢热功 率曲线，目的在于建立微量热法评价鱼类品种优势以及应用微量热法预测杂交优势 的方法。实验得到了不同品种鱼肝线粒体代谢的活性恢复期速率数(k)和总产热量 （Q）。我们认为活性恢复期速率常数的大小表征物种对环境的适应能力，而总产 热量则表征物种的生物活性的大小。同时具有较大活性恢复期速率常数的总产热量 的品种是优势品种，采用活性恢复期速率常数较大的父本和总产热量较大的母本所 获得的后代具有杂交优势的可能性较大。     

线粒体热化学研究──Ⅳ．鱼类肝脏线粒体代谢的微量热学研究

线粒体热化学研究──Ⅳ．鱼类肝脏线粒体代谢的微量热学研究谭安民，刘义，谢昌礼，屈松生，顾贫，邓凤姣（武汉大学化学系武汉４３００７２）（武汉大学生命科学院武汉）关键词鱼肝脏，线粒体，微量热学，热化学线粒体在能量代谢的过程中，除一部分能量用于合成ＡＴＰ外...     

差示扫描量热研究水稻线粒体能量释放动力学

线粒体是细胞的一个重要的亚细胞器．它通过呼吸作用为细胞各项活动提供能量，有细胞'动力戒'之称．生物摄取的食物通过代谢分解形成小分子产物之后，被输送至线粒体，经过氧化作用将其中贮存的能量逐步释放出来，并转化为三磷酸腺苦（ATP）以供生命机体各种活动的需要，因而它     

基因编辑在线粒体疾病中的应用

线粒体作为细胞的能量工厂,在维持细胞能量代谢与人类生命活动中发挥着至关重要的作用.线粒体基因组的突变会导致一系列线粒体遗传代谢疾病的发生,严重威胁人类生命健康,发展靶向线粒体的基因编辑手段对于线粒体疾病的治疗具有重要意义.近年来,以限制性核酸酶、锌指核酸酶、转录激活因子样效应核酸酶、规律成簇的间隔短回文重复序列(CRISPR)以及碱基编辑器为代表的一系列基因编辑方法迅速发展.本文综合评述了基因编辑工具应用于哺乳动物细胞的线粒体DNA的研究进展、不足和发展方向,以期为线粒体疾病治疗技术的开发提供参考.     

水稻线粒体能量释放的量热研究

水稻线粒体能量释放的量热研究＊周培疆＊＊（新疆大学化学系乌鲁木齐８３００４６）谢昌礼屈松生周涵韬＊＊＊凌杏元朱英国（武汉大学化学系武汉大学生命科学学院武汉４３００７２）关键词水稻线粒体能量释放量热热力学动力学中图分类号Ｏ６４２．０３线粒体是真核细胞中...     

线粒体特异性检测与调控

线粒体(mitochondria)是一种由双层膜包被的细胞器,存在于大多数细胞中,能够通过位于线粒体内膜上的呼吸链产生能量,被称为细胞的"能量工厂"。此外,线粒体参与到细胞分化、信息传递和细胞凋亡等过程,并调控细胞周期和细胞生长。线粒体的功能障碍与多种人类疾病相关,如帕金森氏病、阿尔兹海默氏病、心血管疾病和某些癌症等。鉴于其在生物体中的重要作用,线粒体一直是科学家们的研究重点。本文就线粒体特异性检测和调控研究的最新进展进行了综述。     

Microcalorimetric studies on the mitochondria metabolism of Cyprinus Carpio val and its parents

The metabolic thermogenic curves of liver mitochondria isolated from the livers of Cyprinus Carpio vol and its parents were determined at 28°C by using an LKB‐2277 Bioactivity Monitor. The results indicated that their thermogenic curves are different The total heat output and total time of the metabolism of the liver mitochondria of the hybrid F₁ (Cyprinus Carpio val) are more than those of its parents, and its maximum heat power is between that of the female parent and male parent. The relationship between their metabolic thermogenic curves and character of mitochondrial metabolism, and thermokinetics and the heterosis were analyzed and discussed. The character of the mitochondrial thermogenic curves reflected the physiologic character of heterosis. The microcalorimetric method proved to be a probable and sensitive tool for the assessment of heterosis.     

A microcalorimetric study of the action of mercuric chloride on the metabolism of mitochondria isolated from Cyprinus carpio liver tissue

After the occurrence of 'Minamata disease' in 1950, mercury aroused much more attention, and lots of studies concerned have been made. The purpose of the present paper is to study the effect of mercuric chloride on the mitochondria suspension isolated from the liver tissue of Cyprinus carpio from the direct viewpoint of energy by using the microcalorimetric method. The metabolic thermogenic curves of the mitochondria suspension at 25°C were obtained, and the mitochondria metabolic thermokinetic equations were established, from which we obtained the thermodynamic and thermokinetic parameters: thermogenic rate constant (k), heat output (Q), average heat power (P_av), etc. Experimental results indicated that low concentration of mercuric chloride (5 nmol Hg²⁺/(mg protein)) stimulates the thermogenesis of mitochondria, suggesting a strong effect of uncoupling action, while high concentration of mercuric chloride (20 nmol Hg²⁺/(mg protein)) inhibits the metabolism of mitochondria completely, suggesting a fatal effect on the phosphorylation system. The effect of Hg²⁺ on mitochondria is concentration-depended, from which the probable reaction mechanism of Hg²⁺ to the mitochondria was proposed. So the microcalorimetric method can be used in the toxicology research.     

微量热法研究氰化物对鲤鱼肝线粒体代谢的影响

A microcalorimetric technique based on the metabolic heat-output was explored to evaluate the inhibition of cyanide on the mitochondrial metabolism of aquatic animal, Cyprinus carpio. The power-time curves could be divided into four parts： lag phase, active recovery phase, stationary phase, and decline phase, and the corresponding thermokinetic parameters were obtained. The maximum heat production rate Pmax decreased in a linear manner with the increase of concentration of cyanide, however, such mitochondria of aquatic animal were still metabolized actively even under the action of high concentration of cyanide. All the observations suggested that the mitochondria of this aquatic animal should exhibit considerable ability of cyanide-resistant respiration.     

Novel intramolecular coordination chemistry of some new metallocene complexes

The metabolic thermogenic curves of liver mitochondria isolated from the livers of Cyprinus Carpio vol and its parents were determined at 28°C by using an LKB‐2277 Bioactivity Monitor. The results indicated that their thermogenic curves are different The total heat output and total time of the metabolism of the liver mitochondria of the hybrid F₁ (Cyprinus Carpio val) are more than those of its parents, and its maximum heat power is between that of the female parent and male parent. The relationship between their metabolic thermogenic curves and character of mitochondrial metabolism, and thermokinetics and the heterosis were analyzed and discussed. The character of the mitochondrial thermogenic curves reflected the physiologic character of heterosis. The microcalorimetric method proved to be a probable and sensitive tool for the assessment of heterosis.     

Effects of Magnolia officinalis compatibility with Polygala tenuifolia on mitochondrial metabolism in rats’ liver based on bio-thermodynamics

Polygala tenuifolia (Yuanzhi in Chinese) has gastrointestinal toxicity which can be significantly alleviated by Magnolia officinalis (Houpo in Chinese) due to the heat production of mitochondria based on our previous study. In this paper, we have compared the different effects of M. officinalis, P. tenuifolia and their compatibility group on the mitochondrial metabolism in rats liver based on bio-thermodynamics. According to the growth thermogenic curves, we could obtain the exponential growth parameters to reflect the effect of reduced toxicity affected by M. officinalis. We also compared the further functional characteristics of M. officinalis, P. tenuifolia and their compatibility by means of statistical methods. The different experiment concentrations on mitochondrial metabolism were analyzed by principle component analysis (PCA). By analyzing the effect of different experiment concentrations on mitochondrial growth rate, we found that the metabolism rate K of mitochondria in P. tenuifolia group reduced in doses dependently. We obtained the exponential growth constant K and depicted the metabolism thermal power-time curve information of mitochondria at the same time. Our results showed that with the increased concentration of P. tenuifolia extracts, there was significant promotion of heat production by mitochondria while inhibition of M. officinalis extracts and their compatibility extracts. Analyzed by PCA, M. officinalis group distributed more scattered and had far influence on mitochondrial metabolism when compared to M. officinalis group and their compatibility group. It showed that P. tenuifolia’s gastrointestinal side effect was related to the change of mitochondrial energy metabolism.

     

The effect on the longevity of Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) studied by microcalorimetry and traditional methods

The longevity of Leptocybe invasa Fisher & LaSalle (L. invasa) was studied by microcalorimetry and traditional methods, respectively. As regards the results from microcalorimetry, the heat flow in the process of metabolism of L. invasa declined exponentially. With the temperature increasing, the metabolism of L. invasa was inhibited, and the longevity of L. invasa decreased gradually. At 25 °C, the longevity of L. invasa almost reaches 360 h. At 41 °C, L. invasa will die within 18 h. The same phenomenon was observed under the low temperature. The supercooling point can be determined by microcalorimetry because the heat will be released due to the phase change. The survival aspects of L. invasa on high- and low-temperature exposures were also studied by traditional methods. Similar results were obtained in both methods, which indicated that microcalorimetry can be used to measure the metabolism of insect.     

壳聚糖-g-N-羧甲基-2-硫代-4,5-2H咪唑啉酮-多壁碳纳米管复合物固定漆酶基化学传感器的性能

通过壳聚糖-g-N-羧甲基-2-硫代-4,5-2H咪唑啉酮(CTS-g-N-CSIDZ)非共价功能化多壁碳纳米管(MWCNTs)的方式制备固定漆酶载体,该复合物载体主要通过物理吸附和漆酶活性中心与载体上配体之间的配位作用来固定漆酶,较大程度地保持了游离漆酶活性位原始构象.将固定了漆酶的复合物附着在裸玻碳电极上便构筑了复合物固定漆酶修饰玻碳电极.在以分光光度法测定了这种复合物载体对漆酶的担载量、固定漆酶比活力、稳定性、重复使用性及其催化2,6-二甲氧基苯酚(DMP)氧化动力学参数的基础上,还对基于此种复合物固定漆酶修饰玻碳电极作为化学传感器(以DMP作为底物)的性能进行了研究.结果表明,该复合物具有较高的固酶担载量(81.7 mg/g)和固定漆酶比活力(1.33 U/mg);而作为电化学传感器的复合物固定漆酶修饰玻碳电极对底物DMP具有较高的亲和力(对DMP的米氏常数KM是0.0918 mmol/L),较高的灵敏度( 3680 mA· L/mol),较低的检测限(3.3×10-4 mmol/L),较高的响应选择性,良好的重现性、重复使用性和长期稳定性.这种漆酶基电极有望用作电流型特定结构的酚类传感器.     

Heat Shock Treatment Improves Trametes versicolor Laccase Production

An efficient heat shock strategy has been developed to improve laccase production in submerged Trametes versicolor cultures. The optimized heat shock strategy consists of subjecting T. versicolor mycelial pellets to three heat shock treatments at 45?°C for 45?min, starting at culture day?0, with a 24-h interval between treatments. Laccase production increased by more than 1.6-fold relative to the control in both flasks and a 5-L bioreactor because the expression of the laccase gene was enhanced by heat shock induction. The present work demonstrates that heat shock induction is a promising method because it both improves fungal laccase production and has a good potential in industrial application.