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71.
Sasa borealis, a monocarpic species of dwarf bamboo, is widely distributed throughout Korea. It dominates forest floors, thereby inhibiting mainly the biodiversity. Although it flowers very rarely, examples have recently been observed in multiple locations, providing a good opportunity to study reproduction phenomena, and to aid in biodiversity restoration. Therefore, we investigated the nationwide timing of flowering events by using data collected from a social network service (SNS). We also more closely examined flowering and decline event, focusing at the patch and culm levels on Mt. Jeombong. We then analyzed the main factors affecting flowering. Our SNS and survey results showed that S. borealis is in a current flowering cycle that started in 2013 and continues to the present (83% of all events happening within this period) with a peak in 2015 (48% of the cases occurring in that year). This clearly demonstrated nationwide, synchronized, and massive flowering. Although the culm density in patches was not related to flowering, patches with large culms tended to flower (F = 8.241, p = 0.01). We suspected that this nationwide flowering event was triggered by prolonged drought during the spring months of 2014 and 2015 (F = 5.207, p < 0.05), which led to concurrent, massive flowering in patches mature enough to do so. Because this species prefers a wet habitat, we concluded that severe, prolonged drought induced environmental stress for those plants. After flowering, culms in those particular patches tended to die off within one year. This large-scale synchronized decline should have an enormous effect on the vegetation dynamics of a forest dominated and suppressed by Sasa. Future investigations might incorporate methods of ecological control and manipulation to increase biodiversity there. 相似文献
72.
Effect of self-association on the structural organization of partially folded proteins: inactivated actin 总被引:1,自引:0,他引:1 下载免费PDF全文
IM Kuznetsova AG Biktashev SY Khaitlina KS Vassilenko KK Turoverov VN Uversky 《Biophysical journal》1999,77(5):2788-2800
The propensity to associate or aggregate is one of the characteristic properties of many nonnative proteins. The aggregation of proteins is responsible for a number of human diseases and is a significant problem in biotechnology. Despite this, little is currently known about the effect of self-association on the structural properties and conformational stability of partially folded protein molecules. G-actin is shown to form equilibrium unfolding intermediate in the vicinity of 1.5 M guanidinium chloride (GdmCl). Refolding from the GdmCl unfolded state is terminated at the stage of formation of the same intermediate state. An analogous form, known as inactivated actin, can be obtained by heat treatment, or at moderate urea concentration, or by the release of Ca(2+). In all cases actin forms specific associates comprising partially folded protein molecules. The structural properties and conformational stability of inactivated actin were studied over a wide range of protein concentrations, and it was established that the process of self-association is rather specific. We have also shown that inactivated actin, being denatured, is characterized by a relatively rigid microenvironment of aromatic residues and exhibits a considerable limitation in the internal mobility of tryptophans. This means that specific self-association can play an important structure-forming role for the partially folded protein molecules. 相似文献
73.
Hye-Kyung Lee Suk Ji Su-Jin Park Han-Wool Choung Youngnim Choi Hyo-Jung Lee Shin-Young Park Joo-Cheol Park 《The Journal of biological chemistry》2015,290(23):14740-14753
Adhesion of the junctional epithelium (JE) to the tooth surface is crucial for maintaining periodontal health. Although odontogenic ameloblast-associated protein (ODAM) is expressed in the JE, its molecular functions remain unknown. We investigated ODAM function during JE development and regeneration and its functional significance in the initiation and progression of periodontitis and peri-implantitis. ODAM was expressed in the normal JE of healthy teeth but absent in the pathologic pocket epithelium of diseased periodontium. In periodontitis and peri-implantitis, ODAM was extruded from the JE following onset with JE attachment loss and detected in gingival crevicular fluid. ODAM induced RhoA activity and the expression of downstream factors, including ROCK (Rho-associated kinase), by interacting with Rho guanine nucleotide exchange factor 5 (ARHGEF5). ODAM-mediated RhoA signaling resulted in actin filament rearrangement. Reduced ODAM and RhoA expression in integrin β3- and β6-knockout mice revealed that cytoskeleton reorganization in the JE occurred via integrin-ODAM-ARHGEF5-RhoA signaling. Fibronectin and laminin activated RhoA signaling via the integrin-ODAM pathway. Finally, ODAM was re-expressed with RhoA in regenerating JE after gingivectomy in vivo. These results suggest that ODAM expression in the JE reflects a healthy periodontium and that JE adhesion to the tooth surface is regulated via fibronectin/laminin-integrin-ODAM-ARHGEF5-RhoA signaling. We also propose that ODAM could be used as a biomarker of periodontitis and peri-implantitis. 相似文献
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75.
Sheng XC Appleby T Butler T Cai R Chen X Cho A Clarke MO Cottell J Delaney WE Doerffler E Link J Ji M Pakdaman R Pyun HJ Wu Q Xu J Kim CU 《Bioorganic & medicinal chemistry letters》2012,22(7):2629-2634
The discovery of GS-9451 is reported. Modification of the P3 cap and P2 quinoline with a series of solubilizing groups led to the identification of potent HCV NS3 protease inhibitors with greatly improved pharmacokinetic properties in rats, dogs and monkeys. 相似文献
76.
Cho A Zhang L Xu J Babusis D Butler T Lee R Saunders OL Wang T Parrish J Perry J Feng JY Ray AS Kim CU 《Bioorganic & medicinal chemistry letters》2012,22(12):4127-4132
A series of 2'-C-methyl branched purine and pyrimidine C-nucleosides were prepared. Their anti-HCV activity and pharmacological properties were profiled, and compared with known 2'-C-Me N-nucleoside counterparts. In particular, 2'-C-Me 4-aza-7,9-dideazaadenosine C-nucleoside (2) was found to have potent and selective anti-HCV activity in vitro as well as a favorable pharmacokinetic profile and in vivo potential for enhanced potency over the corresponding N-nucleoside. 相似文献
77.
Suk Weon Kim Jong Hyun Kim Myung Suk Ahn Dong-Ho Choung Jang R. Liu 《Plant Cell, Tissue and Organ Culture》2012,108(2):303-313
To investigate the metabolic changes that precede visible organogenesis in tissue culture, tobacco leaf explants were cultured
on media supplemented with various plant growth regulators (PGRs) and analyzed with proton nuclear magnetic resonance (1H NMR) spectroscopy. Principal component analysis (PCA) of 1H NMR spectral data was unable to differentiate between leaf explants cultured with α-naphthaleneacetic acid and those cultured
with 6-benzyladenine after 4 days of culture; however, a difference was evident after 8 days of culture. A hierarchical dendrogram
from PCA analysis could be grouping leaf explants cultured with various auxins separately from those treated by various cytokinins.
However, leaf explants cultured with thidiazuron (TDZ) were identified as an outlier group; TDZ appeared to produce pleiotropic
metabolic effects that differed from those induced by other PGRs. These results show that dedifferentiation can be initiated
by either auxins or cytokinins, which is reflected by similar metabolic changes produced by the two distinct PGRs during the
initial incubation period. The subsequent redifferentiation differs according to the PGR treatment, which is reflected by
differential metabolic changes, depending on the fate of cells in organogenesis. Glutamine and glutamate levels increased
approximately twofold in cytokinin-treated leaf explants compared with auxin-treated explants; however, changes in the levels
of sugar compounds did not differ between the two treatments, demonstrating auxin regulation of the carbon/nitrogen ratio
in favor of rooting. Taken together, our results suggest that 1H-NMR spectroscopy combined with multivariate analysis is a promising means for the metabolic evaluation of plant growth and
differentiation. 相似文献
78.
Rok Seon Choung Eric V. Marietta Carol T. Van Dyke Tricia L. Brantner John Rajasekaran Pankaj J. Pasricha Tianhao Wang Kang Bei Karthik Krishna Hari K. Krishnamurthy Melissa R. Snyder Vasanth Jayaraman Joseph A. Murray 《PloS one》2016,11(1)
Background
Most antibodies recognize conformational or discontinuous epitopes that have a specific 3-dimensional shape; however, determination of discontinuous B-cell epitopes is a major challenge in bioscience. Moreover, the current methods for identifying peptide epitopes often involve laborious, high-cost peptide screening programs. Here, we present a novel microarray method for identifying discontinuous B-cell epitopes in celiac disease (CD) by using a silicon-based peptide array and computational methods.Methods
Using a novel silicon-based microarray platform with a multi-pillar chip, overlapping 12-mer peptide sequences of all native and deamidated gliadins, which are known to trigger CD, were synthesized in situ and used to identify peptide epitopes.Results
Using a computational algorithm that considered disease specificity of peptide sequences, 2 distinct epitope sets were identified. Further, by combining the most discriminative 3-mer gliadin sequences with randomly interpolated3- or 6-mer peptide sequences, novel discontinuous epitopes were identified and further optimized to maximize disease discrimination. The final discontinuous epitope sets were tested in a confirmatory cohort of CD patients and controls, yielding 99% sensitivity and 100% specificity.Conclusions
These novel sets of epitopes derived from gliadin have a high degree of accuracy in differentiating CD from controls, compared with standard serologic tests. The method of ultra-high-density peptide microarray described here would be broadly useful to develop high-fidelity diagnostic tests and explore pathogenesis. 相似文献79.
Wonken Choung Hui Jin Jung Deokmo Yang Eun Hye Nam Hyukjoon Choi Bo Ram Lee Min Park Su Min Jang Jae Soo Lim Woo Sik Kim Kyung-Hee Kim Jungwook Chin Kyungjin Jung Geumwoo Lee Eunmi Hong Tae-ho Jang Jayhyuk Myung Seong Heon Kim 《Bioorganic & medicinal chemistry letters》2019,29(4):631-637
The new class of PPARgamma non-TZD agonist originally derived from the backbone of anti-hypertensive Fimasartan, BR101549, was identified as a potential lead for anti-diabetic drug development. The X-ray crystallography of BR101549 with PPARgamma ligand binding domain (LBD) revealed unique binding characteristics versus traditional TZD full agonists. The lead candidate, BR101549, has been found activating PPARgamma to the level of Pioglitazone in vitro and indeed has demonstrated its effects on blood glucose control in mouse proof-of-concept evaluation. The attempts to improve its metabolic stability profile through follow-up SAR including deuterium incorporation have been also described. 相似文献