人心肌肌球蛋白轻链1的克隆,表达纯化和单抗制备

报道了中国人心肌肌球蛋白轻链１ｃＤＮＡ的核苷酸序列,并由此推算的氨基酸序列。与国外发表的人心肌肌球蛋白轻链的氨基酸序列比较,发现有两处差异,即在２４位,由谷氨酸变为丙氨酸,则从９８位起至１０１位有４个氨基酸序列的连续差异,即由天冬酰胺－精氨酸－丝氨酸－赖氨酸变为赖氨酸－脯氨酸－精氨酸－谷氨酰妥,推测可能是由于人种差异而引起的。利用该ｃＤＮＡ在大肠杆菌内的表达产物,已获得一株高效的抗中国人心肌肌球蛋     

Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther,a MYB domain protein

Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over‐expression of the BR‐synthesis gene D11 or a BR‐signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non‐transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop.     

An off-line filtering ditch–pond system for diffuse pollution control at Wuhan City Zoo

An off-line filtering ditch–pond system was designed and constructed to control the small point and runoff pollution at the Wuhan City Zoo, Hubei Province, China. The quantity and quality of wastewater discharge and runoff from 16 rainfall events were measured to test the effectiveness of the off-line treatment train. The results showed that the water quality was improved and high retention rates for water and pollutants were also achieved by the off-line treatment train. In the outflows, the event mean concentrations (EMCs) of TSS, COD, TN, TDN, TP and TDP were reduced by 75%, 50%, 50%, 57%, 74% and 80% compared to the inflows. In 2005, the annual inflow volume in the catchment was 6783 m³ and the water retention rate was 80.1%. The retention rates in the annual loads of TSS, COD, TN and TP came to 86.4%, 85.5%, 83.9% and 82.9%, respectively. Therefore, the off-line filtering ditch–pond system was shown to be an effective and economical measure to control diffuse pollution. It would be worthwhile to extend the off-line treatment train to regions with limited land resources, especially in urban areas.     

Dissimilarity in the folding of human cytosolic creatine kinase isoenzymes

Creatine kinase (CK, EC 2.7.3.2) plays a key role in the energy homeostasis of excitable cells. The cytosolic human CK isoenzymes exist as homodimers (HMCK and HBCK) or a heterodimer (MBCK) formed by the muscle CK subunit (M) and/or brain CK subunit (B) with highly conserved three-dimensional structures composed of a small N-terminal domain (NTD) and a large C-terminal domain (CTD). The isoforms of CK provide a novel system to investigate the sequence/structural determinants of multimeric/multidomain protein folding. In this research, the role of NTD and CTD as well as the domain interactions in CK folding was investigated by comparing the equilibrium and kinetic folding parameters of HMCK, HBCK, MBCK and two domain-swapped chimeric forms (BnMc and MnBc). Spectroscopic results indicated that the five proteins had distinct structural features depending on the domain organizations. MBCK BnMc had the smallest CD signals and the lowest stability against guanidine chloride-induced denaturation. During the biphasic kinetic refolding, three proteins (HMCK, BnMc and MnBc), which contained either the NTD or CTD of the M subunit and similar microenvironments of the Trp fluorophores, refolded about 10-fold faster than HBCK for both the fast and slow phase. The fast folding of these three proteins led to an accumulation of the aggregation-prone intermediate and slowed down the reactivation rate thereby during the kinetic refolding. Our results suggested that the intra- and inter-subunit domain interactions modified the behavior of kinetic refolding. The alternation of domain interactions based on isoenzymes also provides a valuable strategy to improve the properties of multidomain enzymes in biotechnology.     

Electro-Acupuncture Pretreatment Ameliorates Anesthesia and Surgery-Induced Cognitive Dysfunction Via Inhibiting Mitochondrial Injury and nEuroapoptosis in Aged Rats

Neurochemical Research - Postoperative cognitive dysfunction (POCD) remains one of the most common complications following anesthesia and surgery (AS) in the elderly population. Calcium-mediated...     

Role of Bacterial Communities in the Natural Suppression of Rhizoctonia solani Bare Patch Disease of Wheat (Triticum aestivum L.)

Rhizoctonia bare patch and root rot disease of wheat, caused by Rhizoctonia solani AG-8, develops as distinct patches of stunted plants and limits the yield of direct-seeded (no-till) wheat in the Pacific Northwest of the United States. At the site of a long-term cropping systems study near Ritzville, WA, a decline in Rhizoctonia patch disease was observed over an 11-year period. Bacterial communities from bulk and rhizosphere soil of plants from inside the patches, outside the patches, and recovered patches were analyzed by using pyrosequencing with primers designed for 16S rRNA. Taxa in the class Acidobacteria and the genus Gemmatimonas were found at higher frequencies in the rhizosphere of healthy plants outside the patches than in that of diseased plants from inside the patches. Dyella and Acidobacteria subgroup Gp7 were found at higher frequencies in recovered patches. Chitinophaga, Pedobacter, Oxalobacteriaceae (Duganella and Massilia), and Chyseobacterium were found at higher frequencies in the rhizosphere of diseased plants from inside the patches. For selected taxa, trends were validated by quantitative PCR (qPCR), and observed shifts of frequencies in the rhizosphere over time were duplicated in cycling experiments in the greenhouse that involved successive plantings of wheat in Rhizoctonia-inoculated soil. Chryseobacterium soldanellicola was isolated from the rhizosphere inside the patches and exhibited significant antagonism against R. solani AG-8 in vitro and in greenhouse tests. In conclusion, we identified novel bacterial taxa that respond to conditions affecting bare patch disease symptoms and that may be involved in suppression of Rhizoctonia root rot and bare batch disease.     

甘露醇对渗透胁迫下的鱼腥藻(Anabaena)固氮活性的增效作用

外源甘露醇可在一定程度上增强鱼腥藻Anabaenasp．7120固氮的抗渗透胁迫能力．厌氧（Ar中）、能量供应受阻（暗处理、添加ATP形成的抑制剂）、合成固氮酶蛋白所需物质供应不足（单加N2不加CO2）以及分子氧下,甘露醇的有益作用减小或消失,反之（正常光照、通气环境、提高CO2浓度,同时供应H2和O2或CO2和N2）则这一作用增大。渗透胁迫下,外源蔗糖对甘露醇支持蓝藻固氮的作用不明显。     

转铁蛋白在低钾刺激Madin Darby狗肾细胞钠-钾ATP酶中的作用

体外低钾培养肾细胞能刺激细胞膜钠-钾ATP酶。本研究利用Madin Darby狗肾细胞能在无血清培养液中健康生存48h这一特征,研究体外低钾刺激细胞膜钠-钾ATP酶所依赖的血清中的活性因子,观察了表皮生长因子(EGF)、胰岛素样生长因子(IGF1)、前列腺素1(PGE1)和转铁蛋白(tranderrin)在这一过程中的作用。结果表明,在无血清培养液中低钾并不能刺激细胞膜钠—钾ATP酶,而添加转铁蛋白可模拟血清的作用。转铁蛋白能剂量依赖性地增加ouabain结合位点,对细胞膜钠-钾ATP酶作用呈良好的时间效应关系。在低钾无血清培养液中,细胞膜钠-钾ATP酶α1亚基启动子活性增强,α1与β1亚基蛋白质表达的增加依赖于转铁蛋白的存在。进一步研究结果表明,低钾在转铁蛋白的无血清培养液环境中能增加细胞对铁的摄取(^59Fe),该作用可被铁螯合剂(deferoxamine,DFO;35 μmol/L)所阻断。DFO也可阻断转铁蛋白依赖性低钾刺激细胞膜钠-钾ATP酶数目的增多,α1亚基启动子活性增强,α1与β1亚基蛋白质表达增加。以上结果表明,低钾对细胞膜钠-钾ATP酶活性的刺激作用依赖于转铁蛋白所调节的铁的摄取。