排序方式: 共有45条查询结果,搜索用时 15 毫秒
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Seong Rim Byeon Hyunjin Vincent Kim Mijin Jeon Young Gil Ahn Maeng Sup Kim Jae Yang Kong Hye Yun Kim Young Soo Kim Dong Jin Kim 《Bioorganic & medicinal chemistry letters》2013,23(11):3467-3469
Alzheimer’s disease drug discovery regarding exploration into the molecules and processes has focused on the intrinsic causes of the brain disorder correlated with the accumulation of amyloid-β. An anti-amyloidogenic bis-styrylbenzene derivative, KMS80013, showed excellent oral bioavailability (F = 46.2%), facilitated brain penetration (26%, iv) in mouse and target specific in vivo efficacy in acute AD mouse model attenuating the cognitive deficiency in Y-maze test. Acute toxicity (LD50 >2000 mg/kg) and hERG channel inhibition (14% at 10 μM) results indicated safety of KMS80013. 相似文献
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Kim M Kwon T Lee HJ Kim KH Chung DK Ji GE Byeon ES Lee JH 《Biotechnology letters》2003,25(15):1211-1217
A DNA fragment, which complemented the growth of E. coli both on M9 medium containing raffinose and on LB medium containing ampicillin, IPTG and 5-bromo-4-chloro-3-indoxyl--d-galactoside, was isolated from the genomic library of Bifidobacterium longum SJ32, which had been digested with EcoRI. In the cloned DNA fragment, a gene encoding a sucrose phosphorylase (splP) and a partially cloned putative sucrose regulator gene (splR) were identified using the deletion analysis and sequence analysis. A 56 kDa protein was synthesized in E. coli and partially purified by DEAE-ion exchange chromatography. The partially purified enzyme did not react with melibiose, melezitoze and raffinose but did with sucrose. It had transglucosylation activity in addition to hydrolytic activity. 相似文献
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Mijin Oh Horim Lee Young-Kook Kim Jin-Wu Nam Je-Keun Rhee Byoung-Tak Zhang V. Narry Kim Ilha Lee 《Journal of Plant Biology》2007,50(5):562-572
MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are two major classes of small non-coding RNAs with important roles
in the regulation of gene expression, such as mRNA degradation and translational repression, heterochromatin formation, genome
defense against transposons and viruses in eukaryotes. MiRNA- and siRNA-directed processes have emerged as a regulatory mechanism
for growth and development in both animals and plants. To identify small RNAs that might be involved in vernalization, a process
accelerating flowering brought on by a long period of cold, we generated a library of small RNAs from Arabidopsis that had
been subject to vernalization. From the analysis of the library, 277 small RNAs were identified. They were distributed throughout
all the five chromosomes. While the vast majority of small RNA genes locate on intergenic regions, others locate on repeat-rich
regions, centromeric regions, transposon-related genes, and protein-coding genes. Five of them were mapped to convergent overlapping
gene pairs. Two-hundred and forty of them were novel endogenous small RNAs that have not been cloned yet from plants grown
under normal conditions and other environmental stresses. Seven putative miRNAs were up- or down-regulated by vernalization.
In conclusion, many small RNAs were identified from vernalized Arabidopsis and some of these identified small RNAs may play
roles in plant responses to vernalization. 相似文献
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Prlainović NZ Knežević-Jugović ZD Mijin DZ Bezbradica DI 《Bioprocess and biosystems engineering》2011,34(7):803-810
The objective of this paper was the investigation of a suitable Sepabeads? support and method for immobilization of lipase from Candida rugosa. Three different supports were used, two with amino groups, (Sepabeads? EC-EA and Sepabeads? EC-HA), differing in spacer length (two and six carbons, respectively) and one with epoxy group (Sepabeads? EC-EP). Lipase immobilization was carried out by two conventional methods (via epoxy groups and via glutaraldehyde), and
with periodate method for modification of lipase. The results of activity assays showed that lipase retained 94.8% or 87.6%
of activity after immobilization via epoxy groups or with periodate method, respectively, while glutaraldehyde method was
inferior with only 12.7% of retention. The immobilization of lipase, previously modified by periodate oxidation, via amino
groups has proven to be more efficient than direct immobilization of lipase via epoxy groups. In such a way immobilized enzyme
exhibited higher activity at high reaction temperatures and higher thermal stability. 相似文献
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Kim M Murphy K Liu F Parker SE Dowling ML Baff W Kao GD 《Molecular and cellular biology》2005,25(21):9232-9248
The fidelity of chromosomal duplication is monitored by cell cycle checkpoints operational during mitosis. One such cell cycle delay is invoked by microtubule-targeting agents such as nocodazole or paclitaxel (Taxol) and is mediated by mitotic checkpoint proteins that include BubR1. Relatively little is known about the regulation of expression and stability of BubR1 (or other checkpoint proteins) and how these factors dictate the durability of the cell cycle delay. We report here that treatment of HeLa cells with spindle-disrupting agents resulted in caspase activation and precipitated the cleavage of BubR1. This mechanism ultimately leads to reduced levels of full-length protein, which are accompanied by abrogation of the mitotic block; the checkpoint abrogation is substantially accelerated by inhibition of de novo protein synthesis. In contrast, inhibition of caspase activity blocked BubR1 degradation and prolonged mitosis. To confirm a direct link between caspase activity and BubR1 protein expression, we identified by site-directed mutagenesis the specific caspase cleavage sites cleaved after exposure to paclitaxel. Surprisingly, BubR1 has two sites of cleavage: primarily at Asp607/Asp610 and secondarily at Asp576/Asp579. BubR1 mutated at both locations (BubR1Delta579Delta610) was resistant to paclitaxel-induced degradation. Expression of BubR1Delta579Delta610 augmented the mitotic delay induced by spindle disruption in transfected cells as well as in clones engineered to inducibly express the mutant protein upon exposure to doxycycline and ultimately led to increased aneuploidy. Underscoring the importance of these caspase cleavage sites, both tetrapeptide motifs are identified in the amino acid sequences of human, mouse, chicken, and Xenopus BubR1. These results are potentially the first to link the control of the stability of a key mitotic checkpoint protein to caspase activation, a regulatory pathway that may be involved in killing defective cells and that has been evolutionarily conserved. 相似文献
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Effects of a tryptophanyl substitution on the structure and antimicrobial activity of C-terminally truncated gaegurin 4. 总被引:1,自引:0,他引:1
Hyung-Sik Won Sang-Ho Park Hyung Eun Kim Byongkuk Hyun Mijin Kim Byeong Jae Lee Bong-Jin Lee 《European journal of biochemistry》2002,269(17):4367-4374
Gaegurin 4 (GGN4), a 37-residue antimicrobial peptide, consists of two amphipathic alpha helices (residues 2-10 and 16-32) connected by a flexible loop region (residues 11-15). As part of an effort to develop new peptide antibiotics with low molecular mass, the activities of C-terminally truncated GGN4 analogues were tested. Delta24-37 GGN4, a peptide analogue with 14 residues truncated from the C-terminus of GGN4, showed a complete loss of antimicrobial activity. However, the single substitution of aspartic acid 16 by tryptophan (D16W) in the Delta24-37 GGN4 completely restored the antimicrobial activity, without any significant hemolytic activity. In contrast, neither the D16F nor K15W substitution of the Delta24-37 GGN4 allowed such a dramatic recovery of activity. In addition, the D16W substitution of the native GGN4 significantly enhanced the hemolytic activity as well as the antimicrobial activity. The structural effect of the D16W substitution in the Delta24-37 GGN4 was investigated by CD, NMR, and fluorescence spectroscopy. The results showed that the single tryptophanyl substitution at position 16 of the Delta24-37 GGN4 induced an alpha helical conformation in the previously flexible loop region in intact GGN4, thereby forming an entirely amphipathic alpha helix. In addition, the substituted tryptophan itself plays an important role in the membrane-interaction of the peptide. 相似文献