| Measurement of Cellular Copper in Rhodobacter capsulatus by Atomic Absorption Spectroscopy
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Author:
Date:
2016-10-05
[Abstract] Copper is an essential micronutrient and functions as a cofactor in many enzymes such as heme-Cu oxygen reductases, Cu-Zn superoxide dismutases, multi-copper oxidases and tyrosinases. However, due to its chemical reactivity, free copper is highly toxic (Rae et al., 1999) and all organisms use sophisticated machineries for controlling uptake, storage and export of Cu. The strict control of the cellular Cu homeostasis prevents toxic effects but sustains synthesis of cuproproteins. Monitoring the copper levels within the cell and within different cellular compartments is an essential approach for identifying the contribution of different proteins in maintaining the cellular copper equilibrium. Therefore, whole cells and whole-cell lysates, which can be further fractionated into ...
[摘要] 铜是必需的微量营养素并且在许多酶如辅酶Cu氧还原酶，Cu-Zn超氧化物歧化酶，多铜氧化酶和酪氨酸酶中起辅因子的作用。然而，由于其化学反应性，游离铜是高毒性的（Rae等人，1999），并且所有生物体使用复杂的机器来控制Cu的摄取，储存和输出。严格控制细胞铜稳态防止毒性作用，但维持铜蛋白的合成。监测细胞内和不同细胞区室内的铜水平是识别不同蛋白质在维持细胞铜平衡中的贡献的必要方法。因此，可以进一步分离成细胞质和周质的全细胞和全细胞裂解物被消化，并通过Lowry测定法测定蛋白质浓度。随后，通过原子吸收光谱（AAS）测量铜含量，并计算每mg蛋白质的Cu含量。这提供了产生关于细胞Cu含量的可定量结果的简单且成本有效的方法。为了举例说明这种方法，我们使用光养型α-变形杆菌荚膜红细菌（Rhodobacter capsulatus），其通常用作研究细菌细胞中Cu运输的模式生物体（Ekici等人）。 ，2012）。
[背景] 由于对细胞Cu稳态的兴趣日益增长，在过去几年中开发了用于测量细胞Cu含量的不同方法。它们包括电化学和荧光方案，电感耦合等离子体质谱（ICP-MS），电感耦合等离子体原子发射光谱（ICP-AES），电子微探针分析（EMPA），X射线吸收光谱（XAS）或同步辐射X ...
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| Aspergillus terreus Infection of Fruits and Terrein Quantification by HPLC Analysis
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Author:
Date:
2016-06-20
[Abstract] The opportunistic fungal human and plant pathogen Aspergillus terreus (A. terreus) can be isolated from sea water, soil or decaying organic matter such as rotting leaves and fruits. While growing on fruits A. terreus produces secondary metabolites such as terrein, which may ease its penetration into plant tissues. In addition, biological activities of terrein may support competition against other microorganisms. In summary, terrein is a small polyketide that reduces germination of seedlings, induces lesions on fruit surfaces but also shows moderate antifungal activity. With this manuscript we provide a fruit infection protocol with Aspergillus terreus with subsequent determination of terrein production rates on infected fruits using an HPLC-based ...
[摘要] 机体真菌人和植物病原菌土曲霉（A. terreus）可以从海水，土壤或腐烂的有机物质如腐烂的叶子和果实中分离出来。 当在水果上生长时，A. terreus产生次生代谢物如土曲杆菌，这可以缓解其渗透到植物组织中。 此外，土耳特蛋白的生物活性可能支持与其他微生物的竞争。 总而言之，土豆蛋白是一种减少幼苗发芽的小聚酮，诱发水果表面的病变，但也显示出中等的抗真菌活性。 使用这份手稿，我们提供了一种水果感染方案与土曲霉，随后使用基于HPLC的量化方法测定感染果实的土豆油生产率。
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| Lignin Extraction and Quantification, a Tool to Monitor Defense Reaction at the Plant Cell Wall Level
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Author:
Date:
2015-03-20
[Abstract] Lignin is a complex polymer of phenolic compounds (monolignins), which contributes to the rigidity of the plant cell wall. Lignification is essential for plant development, however it is also one of the mechanisms of plant defense. Accumulation of lignin and the polymerization of monolignins at sides of pathogen attack protect the cell wall against cell wall-degrading enzymes and prevent therefore the pathogen’s penetration. In addition to cross-linkage of phenolic compounds, this resistance mechanism includes also callose and cellulose appositions on the cell wall. This results in structures called papillae, which provide the necessary resistance to the mechanical pressure exercised by fungal appressorium. Lignin accumulation in cell walls is therefore a part of plant defense responses. ...
[摘要] 木质素是酚类化合物（木质素）的复杂聚合物，其有助于植物细胞壁的刚性。木质素是植物发育的关键，但它也是植物防御的机制之一。木质素的积累和木质素在病原体攻击侧的聚合保护细胞壁免受细胞壁降解酶的影响，从而防止病原体的渗透。除了酚类化合物的交联之外，该阻力机制还包括在细胞壁上的胼cal质和纤维素结合。这导致称为乳头的结构，其提供对由真菌附属物施加的机械压力的必要的抵抗力。因此，细胞壁中的木质素积累是植物防御反应的一部分。在这里我们描述了木质素和细胞壁酚类化合物的量化方法，其基于酸催化反应，产生适合于光度测量的有色和可溶性木质素 - 巯基乙酸酯复合物。
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