分类： 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间： 2016-05-12
摘要： Protein disulfide-isomerase (PIN) was the first protein-folding catalyst to be characterized, half a century ago. It plays critical roles in a variety of physiological events by displaying oxidoreductase and redox-regulated chaperone activities. This review provides a brief history of the identification of PDI as both an enzyme and a molecular chaperone and of the recent advances in studies on the structure and dynamics of PDI, the substrate binding and release, and the cooperation with its partners to catalyze oxidative protein folding and maintain ER redox homeostasis. In this review, we highlight the structural features of PDI, including the high interdomain flexibility, the multiple binding sites, the two synergic active sites, and the redox-dependent conformational changes. (C) 2015 Elsevier Inc. All rights reserved.
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2018-10-26 合作期刊: 《广西植物》
摘要： ESI-Q-TOF-MS 因其扫描速度快、灵敏度高等优点，在中药化学成分的鉴定中应用广泛，且能提供碎片离子的精确质量数及可能的元素组成，不易受到药材的生长环境、提取条件等因素的影响，能够较为准确评价陕西不同地区的丹参药材质量。该文采用 ESI-Q-TOF-MS 直接进样分析方法对陕西商州、洛南、大荔、丹凤和铜川等五个地区丹参的化学成分进行比较分析，通过丹参水溶性和脂溶性成分的质谱丰度差异评价不同地区丹参化学成分含量的变化，对不同产地丹参的化学成分进行鉴定，综合分析选出最优丹参种植产地。结果表明：五地丹参均含有丹参酮ⅡA、隐丹参酮、丹参酮Ⅰ、二氢丹参酮、丹参酚酮、次丹参醌、丹参醌Ⅱ等 9 种脂溶性化学成分和丹参素、咖啡酸、阿魏酸、迷迭香酸、原紫草酸、紫草酸、原儿茶醛、丹酚酸 A、丹酚酸 B 等 9 种水溶性化学成分，其中丹参素钠、紫草酸、丹酚酸 B 和隐丹参酮的含量普遍较高，质谱丰度均大于 30%。但是随着种植环境不同，不同地区丹参的化学成分含量差异很大，如商州产丹参中含有较多具有生物活性的丹参酮类物质，其中丹参酮Ⅰ含量远远高于其他四个产地，质谱丰度达到 72.6 %，而其他地区丹参酮Ⅰ的质谱丰度仅为 1.8-11.3 %。研究表明，丹参质量按照地区排序为商州>铜川>大荔>洛南>丹凤。该方法为中药药材质量评价提供了科学、可靠、便捷的途径，为药材规格等级的制定提供了新的途径，为陕西丹参种植区域的选择提供重要信息。
分类： 生物学 >> 生物物理学 提交时间： 2016-05-12
Lu, Ping
Lin, Yin-Hua
Xu, Yan-Peng
Tan, Fei
Jia, Xu-Dong
Lu, Ping
Yang, Zhong-Qi
Wang, Xi-Zhuo
Xu, Yan-Peng
Tan, Fei
Wang, Miao
Xu, De-Rong
摘要： This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p<0.05). We also found a high ratio of fungal-to-bacterial PLFAs in black soil and significant variations in the ratio of monounsaturated-to-branched fatty acids with different straw treatments that correlated with SR (p<0.05). These results indicated that the application of corn straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition.
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