共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
口腔过氧化物酶系统研究进展 总被引:2,自引:0,他引:2
口腔过氧化物酶系统由过氧化物酶、过氧化氢 ( H2 O2 )和可被氧化的底物组成 ,是口腔中重要的非特异性防御因子 ,该系统可通过过氧化氢 ( H2 O2 )及氧化产物维持或促进口腔有益菌的生长和繁殖 ,同时抑制或杀灭致龋菌、牙周可疑病原菌及致口腔粘膜病微生物 ,调节口腔菌群的种类和数量 ,在维持口腔微生态平衡和口腔健康中起着重要的作用 ,本文拟对口腔过氧化物酶系统的组成、生物学功能及其应用作一综述。1 口腔过氧化物酶系统的组成口腔过氧化物酶系统 ( peroxidase system,PS)包括三个组份 :过氧化物酶 ( peroxidase,PO)、过氧化氢 ( H… 相似文献
3.
4.
过氧化物酶体是细胞中一种重要的细胞器.过氧化物酶体在细胞功能的发挥和人体健康方面有着重要作用.目前,以酵母过氧化物酶体为模型,研究过氧化物酶体的形成机制是研究热点.从过氧化物酶体起源、生成方式介绍最新研究进展,总结在酵母细胞中参与过氧化物酶体形成的必需基因(pex),及其编码Peroxin蛋白在过氧化物酶体形成过程中的... 相似文献
5.
植物过氧化物酶超家族的分子结构 总被引:1,自引:0,他引:1
过氧化物酶广泛存在于生物中。基于序列相似性比较,可将真菌、细菌和植物来源的过氧化物酶归为一个超家族-植物过氧化物酶超家族。作者对近几年来植物过氧化物酶超家族的分子结构与功能研究进展,从过氧化物酶的辅基(血红素)微循环结构、过氧化物酶超家族的序列结构域,以及酶分子中底物结合位点和Ca^2+结合位点的结构等方面作了简要评述。 相似文献
6.
7.
除线粒体外,过氧化物酶体也是真核细胞脂肪酸β氧化分解的重要部位.过氧化物酶体β氧化过程包括氧化、加水、脱氢和硫解4步反应,主要参与极长链、支链脂肪酸等的分解.近年关于过氧化物酶体β氧化的研究活跃,在代谢途径及功能等方面有了新的认识,尤其在对相关代谢酶的研究中取得了较大进展.本文就过氧化物酶体β氧化相关进展作一综述. 相似文献
8.
高倩玲胡龄文陈鸿平刘友平陈林胡媛 《天然产物研究与开发》2023,(5):819-827
枸杞为常用“药食同源”中药材,在加工、贮藏、运输等过程中易发生褐变,严重影响枸杞的外观和质量。前期研究发现枸杞中具有较高的过氧化物酶(peroxidase, POD)活性,而过氧化物酶在植物的酶促褐变中发挥着重要作用。为更好地控制枸杞酶促褐变的发生,本研究采用响应面法对枸杞过氧化物酶提取工艺进行优化,对枸杞过氧化物酶的性质进行了研究。结果显示枸杞过氧化物酶最佳提取工艺为料液比1∶3,浸提时间5 h,缓冲液pH为6.0,枸杞过氧化物酶活力为(5 148.59±50.00)U,与模型预测值接近,拟合性好,表明所得响应面模型可以很好地预测和分析枸杞过氧化物酶提取工艺条件。枸杞过氧化物酶最适温度为50℃,最适pH为6.0,金属离子Na~+、Ca~(2+)、K~+、Zn~(2+)、Cu~(2+)和柠檬酸对枸杞过氧化物酶起激活作用,抗坏血酸和亚硫酸能抑制枸杞过氧化物酶活性;该酶酶促反应动力学符合米氏方程,过氧化氢浓度一定时,酶对愈创木酚的K_m=21.52 mmol/L,V_(max)=115.47 U/mL;愈创木酚浓度一定时,酶对H_(2)O_(2)的K_m=1.41 mmol/L,V_(max)=148.81 U/mL。本研究可为后续枸杞加工过程中褐变的控制提供参考。 相似文献
9.
芒果过氧化物酶活性的研究 总被引:7,自引:0,他引:7
从新鲜芒果中提取酶液,进行过氧化物酶活性的测定,结果表明:芒果酶提取液中过氧化物酶最适PH值为4.75,米氏常数Km值为3.23×10^-3mmolH2O2/mL最大反应速度Vmax=0.244O.D/min。在75℃下加热处理20min或80℃下处理5min,可使过氧化物酶完全失活。 相似文献
10.
11.
Summary Several assays of the enzymatic activities of serum cholinesterase, ceruloplasmin and alkaline phosphatase of 30 healthy students during a 9 months period revealed quite constant enzyme levels for each subject. Further, it was observed that most of the subjects maintained a specific enzyme activity value and that the individual range of scatter was characteristic for each one of them.According to our studies it seems probable that quantitative enzyme assays in adults can also be rated as biochemical parameters of individuality.Supported by the Deutsche Forschungsgemeinschaft. 相似文献
12.
ABSTRACT Experimental courses for undergraduate students majoring in biochemistry or related subjects often do not provide students with systematic and research-based experiences. To help students develop abilities related to laboratory techniques, data analysis, and systematic thought in biology, we performed an exploratory program that employs project-based learning in collaborative groups. The participants (total of 18 students) organized themselves into groups of 2–4 students, and each group researched an enzyme that had not been described previously. The program began with a literature survey of enzyme and bioinformatics analysis. The students cloned the gene encoding the enzyme, purified the enzyme, and, finally, analyzed the enzyme’s catalytic characteristics. The students explained the catalytic mechanism, integrating their experimental data and other knowledge. An instructor provided support and training during the process to support effective teamwork and to cultivate a habit of independence that is believed to be useful for the students’ future careers. The assessment showed that the pilot program yielded an improvement in the participant’ laboratory skills, scientific presentation ability, and experimental design ability. These analyses indicated that the small-scale practice in this study provided benefits to the students and the methods may be popularized to a large extent. 相似文献
13.
《Biochemical education》1999,27(2):114-117
An experiment is described in which students carry out urease purification, immobilization and its application in blood urea estimation. Urease from pigeonpea is partially purified using acetone fractionation and then immobilized on calcium alginate in the form of beads. The immobilized enzyme has a better shelf-life at 4°C than soluble enzyme. Various aspects of enzyme immobilization are discussed. Blood urea estimation is carried out with immobilized enzyme beads and the beads can be used repeatedly for this purpose making it an economical procedure compared to commercial kits. 相似文献
14.
《Biochemical education》1999,27(1):2-6
A five day laboratory course in Molecular Biology for PhD students is proposed. The aim of this program, which can be taught by a relatively small staff of experienced scientists, was to introduce basic experimental techniques which are of general use in various fields of biology and biomedicine. These include restriction enzyme purification, restriction mapping, polymerase chain reaction, cloning and DNA sequencing. 相似文献
15.
《Journal of biological education》2012,46(4):305-317
Amylose azure can be used as a chromogenic substrate for α-amylase in studying the effects of temperature and pH on enzyme action. This is a model system which students can use to measure the energy of activation using the Arrhenius plot. The temperature coefficient can also be determined. Further laboratory investigations can be designed to measure optimum pH under varying conditions and the effects of activators on the system. This paper reviews a-amylase action with respect to temperature and pH. Further investigations are suggested. 相似文献
16.
介绍对生物技术和生物工程专业高年级学生开设的“酶工程”课程在教学内容、教学方法等方面的改革。采取产业化案例辅助理论教学的全新授课模式, 主要包括教材和授课内容体现工程特色、产业化案例辅助章节理论和整个课程体系教学、学生参与课堂互动教学等方面。通过教学改革, 收到较好的授课效果。 相似文献
17.
18.
Barrette-Ng IH 《生物化学与分子生物教育》2011,39(4):332-338
In introductory biochemistry courses, it is often a struggle to teach the basic concepts of acid-base chemistry in a manner that is relevant to biological systems. To help students gain a more intuitive and visual understanding of abstract acid-base concepts, a simple graphical construct called the pH ruler Java applet was developed. The applet allows students to visualize the abundance of different protonation states of diprotic and triprotic amino acids at different pH values. Using the applet, the student can drag a widget on a slider bar to change the pH and observe in real time changes in the abundance of different ionization states of this amino acid. This tool provides a means for developing more complex inquiry-based, active-learning exercises to teach more advanced topics of biochemistry, such as protein purification, protein structure and enzyme mechanism. 相似文献
19.
Experiments designed for students in reproductive physiology are rare. Here, we describe a simple experiment concerning a physiological aspect of the reproductive system. Milk samples are obtained from cows in estrus, in midcycle, 21 days after insemination, and in gestation. With these samples, the gestation or estrous stage is determined according to the progesterone level in milk that is measured using enzyme immunoassay. This experiment can therefore be used to demonstrate assay techniques and to illustrate the variations in progesterone concentrations during an estrous cycle and gestation. This exercise should be given after the reproduction section of the animal physiology course so that students can apply their knowledge concerning hormonal profiles during an estrous cycle. 相似文献
20.
《Biochemical education》1999,27(1):45-47
An advanced biochemistry laboratory has been designed to focus on a detoxifying enzyme, glutathione-S-transferase, which is involved in the metabolism of polycyclic aromatic hydrocarbons (PAHs), pesticides, herbicides, and other electrophilic xenobiotic compounds. The enzyme is known to catalyze conjugation of glutathione to xenobiotics, which makes them water-soluble so that they can be easily discarded through further metabolism and excretion. About two-thirds of the laboratory course incorporates nine advanced biochemical techniques, all focused to analyze various chemical characteristics of the glutathione-S-transferase. The remaining third of the semester time students work on a project that involves application of all the newly acquired techniques to solve a biochemical problem that encompasses the same detoxifying enzyme. 相似文献