排序方式: 共有70条查询结果,搜索用时 281 毫秒
51.
52.
Guanqun Zheng John Arne Dahl Yamei Niu Peter Fedorcsak Chun-Min Huang Charles J. Li Cathrine B. Vågbø Yue Shi Wen-Ling Wang Shu-Hui Song Zhike Lu Ralph P.G. Bosmans Qing Dai Ya-Juan Hao Xin Yang Wen-Ming Zhao Wei-Min Tong Xiu-Jie Wang Chuan He 《Molecular cell》2013,49(1):18-29
- Download : Download high-res image (108KB)
- Download : Download full-size image
53.
Fuxin Zhang Ruixi Zhou Tao Yang Kailing Yang Saisai Xin Jingwei Zhang Yuqiu Li Guanqun Zhan Zengjun Guo 《化学与生物多样性》2023,20(6):e202201197
Four undescribed biflavonoid alkaloids, sinenbiflavones A–D, were isolated from Cephalotaxus sinensis using a MS/MS-based molecular networking guided strategy. Their structures were elucidated by series of spectroscopic methods (HR-ESI-MS, UV, IR, 1D, and 2D NMR). Sinenbiflavones A–D are the first examples of amentoflavone-type (C-3’–C-8’’) biflavonoid alkaloids. Meanwhile, sinenbiflavones B and D are the unique C-6-methylated amentoflavone-type biflavonoid alkaloids. Sinenbiflavone D showed weak SARS-CoV-2 3CLpro inhibitory activity with 43 % inhibition rate at 40 μM. 相似文献
54.
Shuo Wang Guanqun Mu Bingquan Qiu Meng Wang Zunbo Yu Weibin Wang Jiadong Wang Yang Yang 《International journal of biological sciences》2021,17(13):3441
Crotonylation is a kind of newly discovered acylation modification. Thousands of crotonylation sites have been identified in histone and non-histone proteins over the past decade. As a modification closely related to acetylation, crotonylation was reported to share many universal enzymes with acetylation. Crotonylated proteins have important roles in the regulation of various biological processes, such as gene expression, process of spermatogenesis, cell cycle, and also in the pathogenesis of different diseases, which range from depression to cancer. In this review, we summarize the research processes of crotonylation and discuss the advances of regulation mechanism of both histone and non-histone proteins crotonylation in difference physiological processes. Also, we focus on the alteration of the crotonylation under certain pathological conditions and its role in the pathogenesis of each disease. 相似文献
55.
Shasha Zhang Guanghou Shui Guanqun Wang Chao Wang Shuhong Sun Christos C. Zouboulis Ran Xiao Jing Ye Wei Li Peng Li 《Molecular and cellular biology》2014,34(10):1827-1838
Sebaceous glands are skin appendages that secrete sebum onto hair follicles to lubricate the hair and maintain skin homeostasis. In this study, we demonstrated that Cidea is expressed at high levels in lipid-laden mature sebocytes and that Cidea deficiency led to dry hair and hair loss in aged mice. In addition, Cidea-deficient mice had markedly reduced levels of skin surface lipids, including triacylglycerides (TAGs) and wax diesters (WDEs), and these mice were defective in water repulsion and thermoregulation. Furthermore, we observed that Cidea-deficient sebocytes accumulated a large number of smaller-sized lipid droplets (LDs), whereas overexpression of Cidea in human SZ95 sebocytes resulted in increased lipid storage and the accumulation of large LDs. Importantly, Cidea was highly expressed in human sebaceous glands, and its expression levels were positively correlated with human sebum secretion. Our data revealed that Cidea is a crucial regulator of sebaceous gland lipid storage and sebum lipid secretion in mammals and humans. 相似文献
56.
Yihan Liu Fuping Lu Guanqun Chen Crystal L. Snyder Jing Sun Yu Li Jianling Wang Jing Xiao 《Biotechnology letters》2010,32(1):119-124
Alpha-amylases are important industrial enzymes with a wide range of applications. Although medium-temperature alpha amylase
(AmyE) has some practical advantages, its low yield has limited its applications. When an amyE gene from Bacillus subtilis BF768 was cloned into vector pWB980 and over-expressed in B. subtilis WB600, high activities (723 U ml−1) of secreted AmyE were produced. Recombinant AmyE was purified to a specific activity of 36 U mg−1 having optimal activity at pH 6.0 and 60°C. 相似文献
57.
Lianghua Lu Chengqi Yi Xing Jian Guanqun Zheng Chuan He 《Nucleic acids research》2010,38(13):4415-4425
N1-meA and N3-meC are cytotoxic DNA base methylation lesions that can accumulate in the genomes of various organisms in the presence of SN2 type methylating agents. We report here the structural characterization of these base lesions in duplex DNA using a cross-linked protein–DNA crystallization system. The crystal structure of N1-meA:T pair shows an unambiguous Hoogsteen base pair with a syn conformation adopted by N1-meA, which exhibits significant changes in the opening, roll and twist angles as compared to the normal A:T base pair. Unlike N1-meA, N3-meC does not establish any interaction with the opposite G, but remains partially intrahelical. Also, structurally characterized is the N6-meA base modification that forms a normal base pair with the opposite T in duplex DNA. Structural characterization of these base methylation modifications provides molecular level information on how they affect the overall structure of duplex DNA. In addition, the base pairs containing N1-meA or N3-meC do not share any specific characteristic properties except that both lesions create thermodynamically unstable regions in a duplex DNA, a property that may be explored by the repair proteins to locate these lesions. 相似文献
58.
High‐performance variants of plant diacylglycerol acyltransferase 1 generated by directed evolution provide insights into structure function
下载免费PDF全文
![点击此处可从《The Plant journal : for cell and molecular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Guanqun Chen Yang Xu Rodrigo M. P. Siloto Kristian Mark P. Caldo Thomas Vanhercke Anna El Tahchy Nathalie Niesner Yongyan Chen Elzbieta Mietkiewska Randall J. Weselake 《The Plant journal : for cell and molecular biology》2017,92(2):167-177
Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the acyl‐CoA‐dependent biosynthesis of triacylglycerol, the predominant component of seed oil. In some oil crops, including Brassica napus, the level of DGAT1 activity can have a substantial effect on triacylglycerol production. Structure–function insights into DGAT1, however, remain limited because of the lack of a three‐dimensional detailed structure for this membrane‐bound enzyme. In this study, the amino acid residues governing B. napus DGAT1 (BnaDGAT1) activity were investigated via directed evolution, targeted mutagenesis, in vitro enzymatic assay, topological analysis, and transient expression of cDNA encoding selected enzyme variants in Nicotiana benthamiana. Directed evolution revealed that numerous amino acid residues were associated with increased BnaDGAT1 activity, and 67% of these residues were conserved among plant DGAT1s. The identified amino acid residue substitution sites occur throughout the BnaDGAT1 polypeptide, with 89% of the substitutions located outside the putative substrate binding or active sites. In addition, cDNAs encoding variants I447F or L441P were transiently overexpressed in N. benthamiana leaves, resulting in 33.2 or 70.5% higher triacylglycerol content, respectively, compared with native BnaDGAT1. Overall, the results provide novel insights into amino acid residues underlying plant DGAT1 function and performance‐enhanced BnaDGAT1 variants for increasing vegetable oil production. 相似文献
59.
Ultraviolet-B radiation improves astaxanthin accumulation in green microalga Haematococcus pluvialis
Zhengyun Wu Guanqun Chen Siukuen Chong Nai-ki Mak Feng Chen Yue Jiang 《Biotechnology letters》2010,32(12):1911-1914
Ultraviolet-B (UV-B) radiation has significantly negative effect on cell survival rate (P < 0.01) and positive effect on astaxanthin accumulation (P < 0.01) of Haematococcus pluvialis. H. pluvialis accumulated 3.2 mg/g of astaxanthin when being exposed to 5 W/m2 of UV-B for 60 min prior to 72 h of high light treatment, which was 122% higher than that of the control. This UV-B treatment
also significantly stimulated lipid peroxidation and the value of malondialdehyde and glutathione peroxidase activities were
156 and 166% higher than those of control, respectively (P < 0.01). 相似文献
60.
丝氨酸蛋白酶抑制剂(Serine Protease Inhibitor,SPI)通过抑制靶蛋白活性参与调节内源蛋白平衡,并在植物发育、防御机制中发挥重要作用。该研究利用RACE技术克隆获得百子莲(Agapanthus praecox ssp.orientalis)ApSPI基因全长序列,构建了E.coli Transetta(pET-32a-ApSPI)重组菌株,并检测重组菌株在不同非生物胁迫下的耐受性。结果显示:(1)ApSPI基因全长为652 bp,开放阅读框为366 bp,编码122个氨基酸。(2)ApSPI蛋白含有一个N端信号肽和一个典型的Kazal结构域,是一种Kazal型丝氨酸蛋白酶抑制剂。重组蛋白最佳诱导温度为37℃,诱导时间6 h,IPTG浓度为0.1 mmol·L~(-1),且主要以可溶性形式存在。(3)重组菌非生物胁迫耐受性研究发现,重组菌Transetta(pET-32a-ApSPI)对NaCl(200~400 mmol·L~(-1))、KCl(200~400 mmol·L~(-1))和PEG6000(5%)的耐受性明显高于对照菌株Transetta(pET-32a)。研究表明,过表达ApSPI蛋白增强了大肠杆菌对盐、干旱胁迫的抗性,为进一步研究ApSPI在植物抗逆中的作用奠定了基础。 相似文献