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111.
Jeong Won Kang Young Gyu Choi Jun Ha Lee Oh Kuen Kwon Ho Jung Hwang 《Molecular simulation》2013,39(9):829-835
Pure carbon nanotube (CNT) oscillators are compared to the corresponding CNT oscillators encapsulating copper nanowires (Cu@CNTs) by molecular dynamics simulations. The classical oscillation theory provides a fairly good estimate of the mass dependence of the operating frequency when the CNT surface is not deformed by the Cu nanowire. The structural deformations of the CNT induced by the encapsulated copper nanowire have a greater effect on the oscillation frequency than the mass of the copper nanowire. The excess forces of the Cu@CNT oscillator are slightly higher than those of the CNT oscillator and the excess van der Waals forces induced by the inter-wall interactions are 17 times higher than the excess forces induced by the Cu nanowire–CNT interactions. 相似文献
112.
Hsuan-Liang Liu Chiao-Kai Hwang Jin-Chung Lin 《Journal of biomolecular structure & dynamics》2013,31(2):131-136
Abstract In this study, various 400 ps molecular dynamics simulations were conducted to determine the stabilizing effect of O-glycosylation on the secondary structural integrity of the design α-loop-α motif, which has the optimal loop length of 7 Gly residues (denoted as N-A16G7A16-C). In general, O-glycosylation stabilizes the structural integrity of the model peptide regardless of the length and position of glycosylation sites because it decreases the opportunity for water molecules to compete for the intramolecular hydrogen bonds. The designed peptide exhibits the highest helicity when residues 11 and 31 are replaced with Ser residues followed by O-linked with 3 galactose residues, representing the “face-to-face” glycosylation near the loop. In this case, the loop exhibits an extended conformation and several new hydrogen bonds are observed between the main chain of the loop and the galactose residues, resulting in decreasing the fluctuation and increasing the stability of the entire peptide. When the glycosylation are made close to the loop, the secondary structural integrity of the α-loop-α motif increases with the number of galactose residues. In addition, “face- to-face” glycosylation increases the structural integrity of this motif to a greater extent than “back-to-back” glycosylation. However, when the glycosylation are created away from the loop and near the N- and C-termini, no general rule is found for the stabilizing effect. 相似文献
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116.
Suman Kundu Talat Roome Ashish Bhattacharjee Kevin A. Carnevale Valentin P. Yakubenko Renliang Zhang Sung Hee Hwang Bruce D. Hammock Martha K. Cathcart 《Journal of lipid research》2013,54(2):436-447
Monocyte chemoattractant protein-1 (MCP-1)-induced monocyte chemotaxis is a major event in inflammatory disease. Our prior studies have demonstrated that MCP-1-dependent chemotaxis requires release of arachidonic acid (AA) by activated cytosolic phospholipase A2 (cPLA2). Here we investigated the involvement of AA metabolites in chemotaxis. Neither cyclooxygenase nor lipoxygenase pathways were required, whereas pharmacologic inhibitors of both the cytochrome-P450 (CYP) and the soluble epoxide hydrolase (sEH) pathways blocked monocyte chemotaxis to MCP-1. To verify specificity, we demonstrated that the CYP and sEH products epoxyeiscosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs), respectively, restored chemotaxis in the presence of the inhibitors, indicating that sEH-derived products are essential for MCP-1-driven chemotaxis. Importantly, DHETs also rescued chemotaxis in cPLA2-deficient monocytes and monocytes with blocked Erk1/2 activity, because Erk controls cPLA2 activation. The in vitro findings regarding the involvement of CYP/sEH pathways were further validated in vivo using two complementary approaches measuring MCP-1-dependent chemotaxis in mice. These observations reveal the importance of sEH in MCP-1-regulated monocyte chemotaxis and may explain the observed therapeutic value of sEH inhibitors in treatment of inflammatory diseases, cardiovascular diseases, pain, and even carcinogenesis. Their effectiveness, often attributed to increasing EET levels, is probably influenced by the impairment of DHET formation and inhibition of chemotaxis. 相似文献
117.
Ching-Hung Lee Yen-Wei Chen Yun-Tzu Huang Yih-Jiuan Pan Chien-Hsien Lee Shih-Ming Lin Lin-Kun Huang Yueh-Yu Lo Yu-Fen Huang Yu-Di Hsu Shih-Chung Yen Jenn-Kang Hwang Rong-Long Pan 《The Journal of membrane biology》2013,246(12):959-966
H+-translocating pyrophosphatase (H+-PPase, EC 3.6.1.1) plays an important role in acidifying vacuoles by transporting protons across membranes at the expense of pyrophosphate (PPi) hydrolysis. Vigna radiata H+-PPase (VrH+-PPase) contains 16 transmembrane helices (TMs). The hydrophobicity of TM3 is relatively lower than that of most other TMs, and the amino acids in this TM are highly conserved in plants. Furthermore, TM5 and -6, which are the core TMs involving in H+-PPase functions, are near TM3. It is thus proposed that TM3 is associated with H+-PPase activity. To address this possibility, site-directed mutagenesis was applied in this investigation to determine the role of TM3 in VrH+-PPase. Upon alanine/serine substitution, T138 and S142, whose side chains face toward the center TMs, were found to be involved in efficient proton transport. G149/S153 and G160/A164 pairs at the crucial termini of the two GxxxG-like motifs are indispensable in maintaining enzymatic activities and conformational stability. Moreover, stability in the vicinity surrounding G149 is pivotal for efficient expression. S153, M161 and A164 are critical for the K+-mediated stimulation of H+-PPase. Taken together, our results demonstrate that TM3 plays essential roles in PPi hydrolysis, proton transport, expression, and K+ stimulation of H+-PPase. 相似文献
118.
Ismail Bezirganoglu Shaw-Yhi Hwang Tony J. Fang Jei-Fu Shaw 《Plant Cell, Tissue and Organ Culture》2013,112(2):227-237
The oriental melon (Cucumis melo L. var. makuwa cv. ‘Silver Light’) is an important fruit crop in the tropical and subtropical regions. However, oriental melon production is severely decreased by fungal diseases. In this study, antifungal protein (AFP) and chitinase (CHI) fusion genes were introduced into oriental melons to control fungal diseases caused by Rhizoctonia solani and Fusarium oxysporum. Transformation of oriental melon (Cucumis melo L. var. makuwa cv. ‘Silver Light’) with Agrobacterium tumefaciens strain LBA4404 containing antifungal protein (AFP) and chitinase (CHI) fusion genes under the control of the cauliflower mosaic virus (CaMV) 35S promoter and neomycin phosphotransferase (nptII) gene as a selectable marker was performed. Cotyledon explants of oriental melon were inoculated by Agrobacterium suspensions with pBI121–AFP–CHI and cultured in a regeneration medium. After regeneration, genomic DNA polymerase chain reaction (PCR) was conducted to confirm the presence of putative transgenic shoots. Southern blot analysis confirmed that the AFP–CHI fusion gene was incorporated into the genomic DNA of the PCR-positive lines. RT-PCR analysis showed that the AFP–CHI fusion gene was expressed in the individual transgenic lines. Western blot analysis revealed the accumulation of CHI protein in leaves. A segregation analysis of the T1 generation confirmed the inheritance of the transgene. Our results demonstrated that the AFP–CHI fusion gene was effective in protecting the transgenic melon plants against fungal disease caused by Rhizoctonia solani and Fusarium oxysporum. 相似文献
119.
H. S. Yoon Y. K. An J. H. Hwang H. S. Lim W. K. Lee K. H. Han S. H. Lee S. D. Choi 《Zeitschrift fur angewandte Ichthyologie》2013,29(2):468-469
Length–weight relationships were estimated for 14 species belonging to 13 fish families from the Suer River estuary, Korea. These 14 species are: Callionymus valenciennei, Konosirus punctatus, Conger myriaster, Cynoglossus joyneri, Tribolodon hakonensis, Thryssa hamiltonii, Acanthogobius flavimanus, Paratrypauchen microcephalus, Hexagrammos agrammus, Nuchequula nuchalis, Pseudopleuronectes yokohamae, Pennahia argentata, Sillago japonica and Takifugu niphobles. Between April 2009 and January 2010, samples were caught by commercial trawl net at depths of <20 m. Estimates for parameter b of the length–weight relationship (W = aLb) ranged between 2.510 and 3.149. 相似文献
120.
Keun Sik Baik Yeoung Min Hwang Jong-Soon Choi Joseph Kwon Chi Nam Seong 《Antonie van Leeuwenhoek》2013,104(6):1143-1150
A motile, curved to twisted rod-shaped aerobic bacterium, designated strain 04SU4-PT, was isolated from freshwater collected from the Woopo wetland (Republic of Korea). Cells were observed to be Gram-stain negative, catalase negative and oxidase positive. The major fatty acids (>10 % of the total) were identified as C19:0 ω8c cyclo (24.6 %), C16:0 (24.3 %) and C18:1 ω7c (13.1 %). The DNA G+C content was determined to be 71.5 mol%. The major polar lipids were identified as phosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown aminolipid. The major ubiquinone was determined to be Q-10. A phylogenetic tree based on 16S rRNA gene sequences showed that strain 04SU4-PT forms an evolutionary lineage within the genus Dongia and its nearest neighbour is Dongia mobilis LM22T (98.0 % sequence similarity). Genomic DNA–DNA hybridization of stain 04SU4-PT with D. mobilis LM22T showed relatedness of only 34.2 %. The phenotypic characteristics indicate the strain 04SU4-PT can be distinguished from the sole member of the genus Dongia. On the basis of the data presented in this study, strain 04SU4-PT represents a novel species, for which the name Dongia rigui is proposed. The type strain is 04SU4-PT (KCTC 23341T = JCM 17521T). 相似文献