共查询到20条相似文献,搜索用时 78 毫秒
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建立了一种新型的酶固定化方法,采用DNA链置换反应成功地在单链DNA标记的磁性纳米粒子上实现了酶的链置换无损更替。该技术可实现目标酶的再利用,节约了生产成本。制备的固定化胰蛋白酶微反应器具有较好的重复利用性和高酶切效率,重复使用10次后仍可保持原酶活性的86%;利用链置换反应制备的MNPs@DNATrypsin酶切马心肌红蛋白5 min后,即可获得95%±0%(n=3)的氨基酸序列覆盖率,远超过相同条件下自由酶酶切12 h的结果。实验表明,发展的固定化酶技术具有高磁响应性,便于从反应体系中回收固定化酶和重复使用,同时此技术可显著提高酶活性,因此可用于固定各种重要的酶,同时可将其广泛应用于各种酶促反应中。 相似文献
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溶解性可调节的酶载体制备和固定化酶的研究 总被引:5,自引:0,他引:5
本文利用自由基沉淀聚合反应,合成了甲基丙烯酸-丙烯酰胺-顺丁烯二酸酐三元共聚物,测定了这些共聚物形成水不溶性的大分子氢键复合物的临界pH值.利用共聚物上的酸酐基团,直接进行了木瓜蛋白酶的固定化,得到了具有液相酶与固相酶两者优点的新型修饰酶。 相似文献
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用悬浮聚合法合成了一系列聚甲基丙烯酸羟乙酯载体,考察了它们固定化酵母脂肪酶活力与载体的交联度和致孔剂用量之间的关系。研究了这些固定化酵母脂肪酶在有机溶剂中催化酯合成反应的活性,脂肪酶的固定化使之活力表达更为充分,对亲水性较强的有机溶剂有更强的耐受性,并能为其在有机溶剂中催化酯合成反应提供必需水。考察了PH值,底物种类对固定化酵母脂肪酶催化酯合成反应的影响。 相似文献
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《Analytical letters》2012,45(9):1631-1641
Abstract The enzymatic cycling for the detection of NAD+ and NADH in low level was carried out in the flow system with immobilized enzymes. Alcohol dehydrogenase and glutamate dehydrogenase immobilized on Sepharose 4B were used for the cycling reaction. The compound produced in the enzymatic cycling reaction was subjected to an enzymatic reaction to yield NADH, which was detected fluorometrically. 相似文献
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Highly Stable Bioluminescence-Based Fiber-Optic Sensor Using Immobilized Enzymes from Vibrio Harveyi
《Analytical letters》2012,45(10):2211-2222
Abstract The properties of the bioluminescent enzymatic systems from V. fischeri and V.harveyi immobilized on preactivated polyamide membranes, as well as the characteristics of a fiber-optic biosensor equipped with such membranes, have been studied. Particular attention has been paid to the stability of the bioactive matrices under working conditions, since this remains a key-point for designing operational biosensors of practical use. Whatever the origin of the bioluminescent system, the microdetermination of NADH could be performed at the nanomolar level with detection limits of 2 nM and 0.3 nM with the systems from V. harveyi and V. fischeri, respectively. the use of polyethyleneglycol (PEG 600) improves the operational stability of the bi-enzymatic system from V. fischeri, but a recalibration must be carried out every ten assays. Although the immobilized system from V. harveyi exhibited a lower activity than the enzymes from V. fischeri, its excellent operational stability (100 assays performed within a day without loss in activity) makes it more suitable in designing a truly operational bioluminescence-based NADH sensor. 相似文献
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基于固定化酶的化学发光停流法测定D-氨基酸 总被引:2,自引:0,他引:2
基于固定化酶的化学发光停流法测定D-氨基酸封满良,黄玉文,宫志龙,章竹君(陕西师范大学化学系,西安,710062)关键词固定化酶,化学发光,甲壳质,D-氨基酸自从发现人体有关组织及血桨中D-氨基酸的水平与某些疾病有关以来,已报道了许多测定D-氨基酸的... 相似文献
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Bhavender P. Sharma Lorraine F. Bailey Ralph A. Messing 《Angewandte Chemie (International ed. in English)》1982,21(11):837-854
The immobilization of enzymes, cofactors and whole cells offers the potential of economical exploitation of biomaterial activity. Enzymes or cells can be immobilized by binding to carriers through adsorption or covalent linkages or by entrapment in a polymer matrix or microencapsulation. The development of immobilized biomaterial systems requires the involvement of biochemical, kinetics and reactor design principles. Examples of commercial scale applications of immobilized biomaterial systems are the production of a fructose-rich syrup from starch and the synthesis of L -amino acids by selective hydrolysis of N-acyl-D ,L -amino acids. 相似文献
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固载化酶催化合成多肽的研究进展 总被引:6,自引:0,他引:6
评述了溶剂、载体性质与固载化方法、pH值、底物浓度以及反应温度等因素对固载化酶催化合成肽反应的影响,并概括了固载化酶催化合成生物活性肽、寡肽等方面的研究与应用. 相似文献
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研究十六烷基三甲基溴化铵(CTAB)-辛烷-己醇反胶束体系固定化醇脱氢酶(ADH)的制备及应用。考察了含水量、CTAB和己醇用量对于ADH固定化的影响。对游离酶和固定化酶的催化动力学性质研究表明:酶促反应的最适pH值分别为8.2和8.8,最适温度分别为31℃和20℃,米氏常数分别为12mmol/L和7mmol/L。30℃时,游离酶存放150min后失活90%,固定化酶失活50%,表明反胶束固定化ADH有较好的热稳定性。应用此体系测定了试样中乙醇的含量。 相似文献
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Guido R. Hartmann 《Angewandte Chemie (International ed. in English)》1976,15(4):181-186
Most intracellular enzymes are made up of several identical or different subunits. The more remote any two organisms are phylogenetically, the greater will be the differences in amino acid sequence of a given enzyme. Nevertheless, numerous examples exist of specific association between chemically different subunits, or even of the formation of enzyme chimeras. They span not only the boundaries between related organisms but also the deep rift between prokaryotic and eukaryotic cells. Exchange of subunits between enzymes of similar activity but differing origin can be rationalized by assuming enzymes to posses functionally defined types of three-dimensional structures. 相似文献
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纳米粒子作为酶固定化的载体,当其具有磁性时,制备的固定化酶易于从反应体系中分离和回收,操作简便;并且利用外部磁场可以控制磁性材料固定化酶的运动方式和方向,替代传统的机械搅拌方式,提高固定化酶的催化效率。在众多纳米材料中,氧化铁因其在磁性、催化等多方面的良好特性而倍受瞩目。本文对近年来各种氧化铁磁性纳米粒子固定化酶,尤其是固定化脂肪酶和蛋白酶的制备方法及其应用做了较为详细的阐述,对这些氧化铁磁性纳米粒子固定化酶的优缺点和发展前景进行了讨论。 相似文献
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A new method for the enzymatic synthesis of agmatine by immobilized Escherichia coli cells with arginine decarboxylase(ADC) activity was established and a series of optimal reaction conditions was set down. The arginine decarboxylase showed the maximum activity when the pyridoxal phosphate(PLP) concentration was 50 mmol/L, pH=7 and 45 °C. The arginine decarboxylase exhibited the maximum production efficiency when the substrate concentration was 100 mmol/L and the reaction time was 15 h. It was also observed that the appropriate concentration of Mg2+, especially at 0.5 mmol/L promoted the arginine decarboxylase activity; Mn2+ had little effect on the arginine decarboxylase activity. The inhibition of Cu2+ and Zn2+ to the arginine decarboxylase activity was significant. The immobilized cells were continuously used 6 times and the average conversion rate during the six-time usage was 55.6%. The immobilized cells exhibited favourable operational stability. After optimization, the maximally cumulative amount of agmatine could be up to 20 g/L. In addition, this method can also catalyze D,L-arginine to agmatine, leaving the pure optically D-arginine simultaneously. The method has a very important guiding significance to the enzymatic preparation of agmatine. 相似文献