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981.
Xiao‐Peng Zhang Tao Wu Jian Liu Jin‐Cheng Zhao Cheng‐Hui Li Xiao‐Zeng You 《Chirality》2013,25(7):384-392
Two couples of enantiomeric platinum(II) complexes: Pt(L1a)Cl ( 1a ), Pt(L1b)Cl ( 1b ) and Pt(L1a)(C ≡ C ? Ph) ( 2a ), Pt(L1b)(C ≡ C ? Ph) ( 2b ) (L1a = (+)‐1,3‐di‐(2‐(4,5‐pinene)pyridyl)benzene, L1b = (?)‐1,3‐di‐(2‐(4,5‐pinene)pyridyl)benzene) were synthesized and characterized. Their absolute configurations were determined by single crystal X‐ray diffraction and further verified by circular dichroism (CD) spectra (including electronic circular dichroism [ECD] and vibrational circular dichroism [VCD]). These complexes show interesting mechanoluminescence and/or vapoluminescence due to crystalline‐to‐amorphous transformation. The crystalline solids, grinding‐induced amorphous powders, and vapor‐induced amorphous powders of complexes 2a and 2b were comparatively investigated by solid‐state ECD and VCD spectra. The transformation from crystalline solids to amorphous powders was accompanied by significant variances of the spectral feature in both ECD and VCD spectra. Chirality 25:384–392, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
982.
Shan Zhu Xiaoping Zhou Xiaomei Wu Zhonghao Jiang 《Plant Molecular Biology Reporter》2013,31(6):1193-1202
Calcium is a crucial messenger in many growth and developmental processes in plants. The central mechanism governing how plant cells perceive and respond to environmental stimuli is calcium signal transduction, a process through which cellular calcium signals are recognized, decoded, and transmitted to elicit downstream responses. In the initial decoding of calcium signals, Ca2+ sensor proteins that bind Ca2+ and activate downstream signaling components are implicated, thereby regulating specific physiological and biochemical processes. After calcineurin B-like proteins (CBLs) sense these Ca2+ signatures, these proteins interact selectively with CBL-interacting protein kinases (CIPKs), thereby forming CBL/CIPK complexes, which are involved in decoding calcium signals. Therefore, specificity, diversity, and complexity are the main characteristics of the CBL-CIPK signaling system. However, additional CBLs, CIPKs, and CBL/CIPK complexes remain to be identified in plants, and the specific functions of their abiotic and biotic stress signaling will need to be further dissected. Therefore, a much-needed synthesis of recent findings is important to further the study of CBL-CIPK signaling systems. Here, we review the structure of CBLs and CIPKs, discuss the current knowledge of CBL–CIPK pathways that decode calcium signals in Arabidopsis, and link plant responses to a variety of environmental stresses with specific CBL/CIPK complexes. This will provide a foundation for future research on genetically engineered resistant plants with enhanced tolerance to various environmental stresses. 相似文献
983.
984.
Meng-Ze Du Feng-Biao Guo Yue-Yun Chen 《Journal of biomolecular structure & dynamics》2013,31(2):391-401
Abstract In this paper, we re-annotated the genome of Pyrobaculum aerophilum str. IM2, particularly for hypothetical ORFs. The annotation process includes three parts. Firstly and most importantly, 23 new genes, which were missed in the original annotation, are found by combining similarity search and the ab initio gene finding approaches. Among these new genes, five have significant similarities with function-known genes and the rest have significant similarities with hypothetical ORFs contained in other genomes. Secondly, the coding potentials of the 1645 hypothetical ORFs are re-predicted by using 33 Z curve variables combined with Fisher linear discrimination method. With the accuracy being 99.68%, 25 originally annotated hypothetical ORFs are recognized as non-coding by our method. Thirdly, 80 hypothetical ORFs are assigned with potential functions by using similarity search with BLAST program. Re-annotation of the genome will benefit related researches on this hyperthermophilic crenarchaeon. Also, the re-annotation procedure could be taken as a reference for other archaeal genomes. Details of the revised annotation are freely available at http://cobi.uestc.edu.cn/resource/paero/ 相似文献
985.
Xian-li Feng Hui Yu Tie-dong Sun 《Journal of biomolecular structure & dynamics》2013,31(10):1086-1100
Molecular dynamics simulations were performed for investigating the thermal stability of the extremely thermophilic Thermoanaerobacter tengcongensis ribose binding protein (tteRBP) and the mesophilic homologous Escherichia coli ribose binding protein (ecRBP). The simulations for the two proteins were carried out under the room temperature (300?K) and the optimal activity temperature (tteRBP 375?K and ecRBP 329?K), respectively. The comparative analyses of the trajectories show that the two proteins have stable overall structures at the two temperatures; further analyses indicate that they both have strong side-chain interactions and different backbone flexibilities at the different temperatures. The tteRBP 375?K and ecRBP 329?K have stronger internal motion and higher flexibility than tteRBP 300?K and ecRBP 300?K, respectively, it is noted that the flexibility of tteRBP is much higher than that of ecRBP at the two temperatures. Therefore, tteRBP 375?K can adapt to high temperature due to its higher flexibility of backbone. Combining with the researches by Cuneo et al., it is concluded that the side-chain interactions and flexibility of backbone are both the key factors to maintain thermal stability of the two proteins. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:22 相似文献
986.
Jianwei He Linan Xu Zhiyuan Zou Nobuhiro Ueyama Hui Li Akio Kato 《Journal of biomolecular structure & dynamics》2013,31(10):1101-1110
Chicken cystatin (cC) mutant I66Q is located in the hydrophobic core of the protein and increases the propensity for amyloid formation. Here, we demonstrate that under physiological conditions, the replacement of Ile with the Gln in the I66Q mutant increases the susceptibility for the disulfide bond Cys71–Cys81 to be reduced when compared to the wild type (WT) cC. Molecular dynamics (MD) simulations under conditions favoring cC amyloid fibril formation are in agreement with the experimental results. MD simulations were also performed to investigate the impact of disrupting the Cys71–Cys81 disulfide bond on the conformational stability of cC at the atomic level, and highlighted major disruption to the cC appendant structure. Domain swapping and extensive unfolding has been proposed as one of the possible mechanisms initiating amyloid fibril formation by cystatin. Our in silico studies suggest that disulfide bond formation between residues Cys95 and Cys115 is necessary to maintain conformational stability of the I66Q mutant following breakage of the Cys71–Cys81 disulfide bridge. Subsequent breakage of disulfide bond Cys95–Cys115 resulted in large structural destabilization of the I66Q mutant, which increased the α–β interface distance and expanded the hydrophobic core. These experimental and computational studies provide molecular-level insight into the relationship between disulfide bond formation and progressive unfolding of amyloidogenic cC mutant I66Q. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:23 相似文献
987.
988.
Xiao‐Jun Guan Lin Song Feng‐Feng Han Zhi‐Lei Cui Xi Chen Xue‐Jun Guo Wei‐Guo Xu 《Journal of cellular biochemistry》2013,114(2):323-335
Progressive pulmonary inflammation and emphysema have been implicated in the progression of chronic obstructive pulmonary disease (COPD), while current pharmacological treatments are not effective. Transplantation of bone marrow mesenchymal stem cells (MSCs) has been identified as one such possible strategy for treatment of lung diseases including acute lung injury (ALI) and pulmonary fibrosis. However, their role in COPD still requires further investigation. The aim of this study is to test the effect of administration of rat MSCs (rMSCs) on emphysema and pulmonary function. To accomplish this study, the rats were exposed to cigarette smoke (CS) for 11 weeks, followed by administration of rMSCs into the lungs. Here we show that rMSCs infusion mediates a down‐regulation of pro‐inflammatory mediators (TNF‐α, IL‐1β, MCP‐1, and IL‐6) and proteases (MMP9 and MMP12) in lung, an up‐regulation of vascular endothelial growth factor (VEGF), VEGF receptor 2, and transforming growth factor (TGFβ‐1), while reducing pulmonary cell apoptosis. More importantly, rMSCs administration improves emphysema and destructive pulmonary function induced by CS exposure. In vitro co‐culture system study of human umbilical endothelial vein cells (EA.hy926) and human MSCs (hMSCs) provides the evidence that hMSCs mediates an anti‐apoptosis effect, which partly depends on an up‐regulation of VEGF. These findings suggest that MSCs have a therapeutic potential in emphysematous rats by suppressing the inflammatory response, excessive protease expression, and cell apoptosis, as well as up‐regulating VEGF, VEGF receptor 2, and TGFβ‐1. J. Cell. Biochem. 114: 323–335, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
989.
Wei Guo Dong Ren Xiuting Chen Xiang'an Tu Shuai Huang Min Wang Libing Song Xuenong Zou Xinsheng Peng 《Journal of cellular biochemistry》2013,114(7):1606-1615
The principal problem arising from prostate cancer (PCa) is its propensity to metastasize to bones, and it's crucial to understand the mechanism of tumor progression to metastasis in order to develop therapies that may reduce the morbidity and mortality of PCa patients. Although we had identified that microRNA(miR)‐145 could repress bone metastasis of PCa via regulating epithelial–mesenchymal transition (EMT) in previous study, it is still unknown how miR‐145 regulated EMT. In the present study, we constructed a luciferase reporter system and identified HEF1 as a direct target of miR‐145. More importantly, HEF1 was shown to promote migration, invasion and EMT of PC‐3 cells, a human PCa cell line originated from a bone metastatic PCa specimen. And HEF1 was also shown to partially mediate miR‐145 suppression of EMT and invasion. Furthermore, inhibition of HEF1 repressed bone invasion of PC‐3 cells in vivo. Expression of HEF1 was negatively correlated with miR‐145 in primary PCa and bone metastatic specimens, but HEF1 was higher in samples which were more likely to commit to bone metastasis or those with higher free prostate‐specific antigen (fPSA) levels and Gleason scores. Taken together, these findings indicate that HEF1 promotes EMT and bone invasion in prostate cancer by directly targeted by miR‐145, and miR‐145 suppresses EMT and invasion, at least in part, through repressing HEF1. J. Cell. Biochem. 114: 1606–1615, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
990.
Chuan-yu Guo Guang-heng Wu Jin Xing Wen-qi Li Ding-zhong Tang Bai-ming Cui 《Plant cell reports》2013,32(5):687-702