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1.
Ai‐Xin Song Chen‐Jie Zhou Xiao Guan Kong‐Hung Sze Hong‐Yu Hu 《Protein science : a publication of the Protein Society》2010,19(5):1104-1109
DC‐UbP/UBTD2 is a ubiquitin (Ub) domain‐containing protein first identified from dendritic cells, and is implicated in ubiquitination pathway. The solution structure and backbone dynamics of the C‐terminal Ub‐like (UbL) domain were elucidated in our previous work. To further understand the biological function of DC‐UbP, we then solved the solution structure of the N‐terminal domain of DC‐UbP (DC‐UbP_N) and studied its Ub binding properties by NMR techniques. The results show that DC‐UbP_N holds a novel structural fold and acts as a Ub‐binding domain (UBD) but with low affinity. This implies that the DC‐UbP protein, composing of a combination of both UbL and UBD domains, might play an important role in regulating protein ubiquitination and delivery of ubiquitinated substrates in eukaryotic cells. 相似文献
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After observing specimens of Calligonum pumilum Losinsk. and C. juochiangense Y. X. Liou in both the field and in herbarium collections, it was found that the morphological characters of these two species are quite different, especially with respect of the twisted direction of fruit ribs, number of bristle rows along each rib, rigidity and degree of interweaving of bristles, as well as their geographic distribution. Therefore, it is concluded that C. pumilum and C. juochiangense should be accepted as two independent species. 相似文献
4.
Isoelectric focusing in immobilized pH gradients of a snake venom fibrinolytic enzyme 总被引:1,自引:0,他引:1
A fibrinolytic enzyme with a molecular weight between 23,000 and 25,000 Da has been purified from southern copperhead snake venom. Immobilized pH gradient isoelectric focusing with an ultranarrow pH interval (pH 6.65-6.95) resolved two isoforms of the fibrinolytic enzyme that were not resolved by standard isoelectric focusing. Attempts at purification of the individual isoenzymes by semi-preparative scale IPG and elution of enzyme by macerating the gel yielded only 20-40% recovery of activity. In attempts to improve recovery, a semi-preparative IPG canal-isoelectric focusing technique has been utilized. 相似文献
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Lipid Composition in Scrapie-Infected Mouse Brain: Prion Infection Increases the Levels of Dolichyl Phosphate and Ubiquinone 总被引:1,自引:0,他引:1
Zhizhong Guan Magnus Söderberg Pavel Sindelar Stanley B. Prusiner †Krister Kristensson Gustav Dallner 《Journal of neurochemistry》1996,66(1):277-285
Abstract: The neutral and phospholipid composition of mouse brain infected with scrapie prions was investigated. During the later stages of this disease, the level of dolichol decreased by 30% whereas the level of dolichyl phosphate increased by 30%. In terminally ill mice, there was also a 2.5-fold increase in both total ubiquinone and its reduced form. Furthermore, α-tocopherol was elevated at this stage by 50%. In contrast, no changes were observed in phospholipid amount, in phospholipid composition, and in phosphatidylethanolamine plasmalogen content during the entire disease process. The fatty acid and aldehyde composition of individual phospholipids remained unaltered as well. No modifications could be detected in cholesterol content. Thus, the majority of membrane lipids in scrapie-infected mouse brain are modified in neither quantity nor structure, but specific changes occur to a few polyisoprenoid lipids. This specificity indicates that, although prions accumulate in lysosomes, the infection process is not associated with a general membrane destruction caused by lysosomal enzyme leakage. 相似文献
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Abstract Isolation and identification of allatostatin 4 (AST 4) from crude brain extracts of female Diploptera punctata are described. Synthetic analogues of allatostatin 4 truncated from the N-terminal were evaluated to gain some knowledge of structure-activity correlation. AST 4 reversibly inhibits the biosynthesis of JH in vitro . AST 4 has the following sequence: Asp-Arg-Leu-Tyr-Ser-Phe-Gly-Leu-NH2 . This neurohormone (AST 4) has no sequence similarity with any known neuropeptide from other organisms. Synthetic AST 4 as well as truncation fragments, including two with the five and six amino acids terminal residues deleted showed in vitro activity distinguishable from that of the native allatostatin. 相似文献
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沿海防护林防海煞危害初探 总被引:2,自引:0,他引:2
通过后牧村海岸防护林带附近空气中主要盐离子飘尘的观测分析表明,林带对大气盐尘的吸附和截留作用,无林带地区平均沉降量为4.3μg.m^-3.100m^-1,通过林带时为18.4μm^-3.100m^-1。林带的吸队量与树种、枝叶形状有关,侧柏对Cl^-和Na^+的吸附量分别为6330和3350mg.kg^-1,而黑松为1570和950mg.kg^-1,空气中盐尘受天气条件特别是风速的影响,阴天,风速 相似文献
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零下低温对杂交杨树皮层膜脂组成的影响 总被引:3,自引:0,他引:3
以不耐寒的美洲黑杨(Populusdeltoidescv.“Lux”I-69/55,父本)和耐寒性较强的欧美杨(P.euramericanaclcv.I-45/51,母本)的4个杂交F_1代无性系(95杨、559杨、600杨和1381杨)为材料,分析了零下低温寒潮前后枝条皮层的脂质组成。结果表明,寒潮影响下,皮层中磷脂含量增加而组成基本不变,膜脂脂肪酸组成的变化规律是:寒潮前脂肪酸不饱和指数(IUFA)值大的无性系,寒潮前后的IUFA值变化量小;寒潮前IUFA值较小的无性系,寒潮前后IUFA值变化量较大。本文借用力学概念,提出相对抗性概念,给出杨树无性系的相对抗性序列。序列表明F_1代无性系的耐寒性已较不耐寒的父本提高,这与田间观察基本一致。 相似文献
10.
瓜类刺盘孢诱导物对新疆甜瓜抗病相关酶活性的影响 总被引:1,自引:0,他引:1
李冠 《Acta Botanica Sinica》1993,(4)
近年来,应用病毒、细菌、真菌以及病原菌体及其代谢物作为诱导因子,已在多种作物上获得对病害的整体免疫,有些已开始在田间应用。我们也曾应用人工诱导免疫的方法使新疆甜瓜获得对瓜类疫霉病的抗性,但有关植物人工诱导免疫机理的研究,目前国外报道不多,国内尚未见报道。本文以瓜类刺盘孢(Colletotrichum langenarium)培养滤液和菌丝细胞壁作为诱导物,研究了免疫植株相关酶的活性以及可溶性蛋白的变化,探讨了人工诱导免疫的机理。 相似文献