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121.
Nucleic acid-based aptamers offer many potential advantages relative to antibodies and other protein-based affinity reagents, including facile chemical synthesis, reversible folding, improved thermal stability and lower cost. However, their selection requires significant time and resources and selections often fail to yield molecules with affinities sufficient for molecular diagnostics or therapeutics. Toward a selection technique that can efficiently and reproducibly generate high performance aptamers, we have developed a microfluidic selection process (M-SELEX) that can be used to obtain high affinity aptamers against diverse protein targets. Here, we isolated DNA aptamers against three protein targets with different isoelectric points (pI) using a common protocol. After only three rounds of selection, we discovered novel aptamer sequences that bind to platelet derived growth factor B (PDGF-BB; pI = 9.3) and thrombin (pI = 8.3) with respective dissociation constants (Kd) of 0.028 nM and 0.33 nM, which are both superior to previously reported aptamers against these targets. In parallel, we discovered a new aptamer that binds to apolipoprotein E3 (ApoE; pI = 5.3) with a Kd of 3.1 nM. Furthermore, we observe that the net protein charge may exert influence on the affinity of the selected aptamers. To further explore this relationship, we performed selections against PDGF-BB under different pH conditions using the same selection protocol, and report an inverse correlation between protein charge and aptamer Kd. 相似文献
122.
Jung TW Lee MW Lee YJ Kim SM 《Biochemical and biophysical research communications》2012,417(1):147-152
Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway. 相似文献
123.
Lovelia Mamuad Seon Ho Kim Chang Dae Jeong Yeon Jae Choi Che Ok Jeon Sang-Suk Lee 《Journal of microbiology (Seoul, Korea)》2014,52(2):120-128
The metabolic pathways involved in hydrogen (H2) production, utilization and the activity of methanogens are the important factors that should be considered in controlling methane (CH4) emissions by ruminants. H2 as one of the major substrate for CH4 production is therefore should be controlled. One of the strategies on reducing CH4 is through the use of hydrogenotrophic microorganisms such as fumarate reducing bacteria. This study determined the effect of fumarate reducing bacteria, Mitsuokella jalaludinii, supplementation on in vitro rumen fermentation, CH4 production, diversity and quantity. M. jalaludinii significantly reduced CH4 at 48 and 72 h of incubation and significantly increased succinate at 24 h. Although not significantly different, propionate was found to be highest in treatment containing M. jalaludinii at 12 and 48 h of incubation. These results suggest that supplementation of fumarate reducing bacteria to ruminal fermentation reduces CH4 production and quantity, increases succinate and changes the rumen microbial diversity. 相似文献
124.
Muhammad Yasir Haji Khan Syed Sikander Azam Amar Telke Seon Won Kim Young Ryun Chung 《Journal of microbiology (Seoul, Korea)》2013,51(3):329-335
In the vermicomposting of paper mill sludge, the activity of earthworms is very dependent on dietetic polysaccharides including cellulose as energy sources. Most of these polymers are degraded by the host microbiota and considered potentially important source for cellulolytic enzymes. In the present study, a metagenomic library was constructed from vermicompost (VC) prepared with paper mill sludge and dairy sludge (fresh sludge, FS) and functionally screened for cellulolytic activities. Eighteen cellulase expressing clones were isolated from about 89,000 fosmid clones libraries. A short fragment library was constructed from the most active positive clone (cMGL504) and one open reading frame (ORF) of 1,092 bp encoding an endo-β-1,4-glucanase was indentified which showed 88% similarity with Cellvibrio mixtus cellulase A gene. The endo-β-1,4-glucanase cmgl504 gene was overexpressed in Escherichia coli. The purified recombinant cmgl504 cellulase displayed activities at a broad range of temperature (25–55°C) and pH (5.5–8.5). The enzyme degraded carboxymethyl cellulose (CMC) with 15.4 U, while having low activity against avicel. No detectable activity was found for xylan and laminarin. The enzyme activity was stimulated by potassium chloride. The deduced protein and three-dimensional structure of metagenome-derived cellulase cmgl504 possessed all features, including general architecture, signature motifs, and N-terminal signal peptide, followed by the catalytic domain of cellulase belonging to glycosyl hydrolase family 5 (GHF5). The cellulases cloned in this work may play important roles in the degradation of celluloses in vermicomposting process and could be exploited for industrial application in future. 相似文献
125.
NLRP10 is a member of the NLRP protein family, which is involved in inflammation and apoptosis. Genome sequence comparisons revealed that a 2.7-kb deletion occurred in the human NLRP10 gene exon 2 after the divergence of humans and chimpanzees, resulting in replacement of the entire 3′ untranslated region with the flanking LINE-1 element. The human NLRP10 protein lost 30 or more amino acids that are conserved in primates at its carboxy-terminus. The structural modification of the NLRP10 gene might have played a role in development or enhancement of human-specific traits during evolution. 相似文献
126.
Hung Sun Koh Jinxing Wang Bae Kun Lee Byong Guk Yang Seon Wook Heo Kyung Hee Jang Tae Yong Chun 《Biochemical genetics》2009,47(1-2):1-7
In the full sequences of the mtDNA cytochrome b gene, 26 haplotypes (Tamias sibiricus barberi) from six localities of central and southern Korea were distinct from 21 haplotypes (Tamias sibiricus orientalis) from five localities of northeast China and Vladivostok, Russia. The average Tamura–Nei nucleotide distance between the subspecies (11.40%) and maximum infrasubspecific distances (3.74% and 4.72%) support the subspecies classification of T. s. barberi based on morphometric comparison. The 26 haplotypes of T. s. barberi were also distinct from 2 haplotypes of T. s. orientalis and Tamias sibiricus jacutensis from far-east Russia (average distance, 11.86%). Thus T. s. barberi constitutes a “phylogroup” (average nucleotide distance > 10%); analyses with nuclear genes of northeast Asian specimens, including North Korean ones, are necessary to clarify its taxonomic status. Furthermore, 49 haplotypes of T. sibiricus from eastern Asia differed from 19 haplotypes of another 18 Tamias spp. from America (weighted-average distance, 18.58%). T. sibiricus is, therefore, distinct enough to be recognized as a subgenus, Eutamias. 相似文献
127.
Overexpression of Regulator of Calcineurin 1 (RCAN1/DSCR1/Adapt78) is known to inhibit the calcineurin-NFAT dependent signaling pathway. In this report, we find that activation of adenylate cyclase by forskolin increases the expression of RCAN1 through the increase of the protein’s half-life. The ability of forskolin to increase the accumulation of RCAN1 protein is significantly inhibited with protein kinase A inhibitors such as KT5720 and H-89. Furthermore, forskolin targets the central and C-terminal region of RCAN1 and enhances the inhibitory effect of RCAN1 on the calcineurin-mediated activation of NFAT. Our findings provide the first evidence that the accumulation of the RCAN1 protein by cAMP acts as an important regulatory mechanism in the control of the calcineurin-dependent cellular pathway.
Structured summary
MINT-7262390: PKA (uniprotkb:P22694) phosphorylates (MI:0217) RCAN1 (uniprotkb:P53805) by protein kinase assay (MI:0424) 相似文献128.
Yi Jin Ling Duan Seon Hwa Lee Helenius J. Kloosterboer Ian A. Blair Trevor M. Penning 《The Journal of biological chemistry》2009,284(15):10013-10022
129.
Jeong‐Han Kang Hyun‐Ji Cho In‐Seon Lee Moonkyu Kim In‐Kyu Lee Young‐Chae Chang 《Proteomics》2009,9(19):4445-4456
Transforming growth factor‐β1 (TGF‐β1) has a wide range of biological functions such as the regulation of cell growth, differentiation, and immunological response in various types of cells. Particularly, TGF‐β1 induces plasminogen activator inhibitor‐1 (PAI‐1) as a major target protein. PAI‐1 is associated with fibrosis, thrombosis, and metabolic disorders. In this study, to identify proteins potentially involved in TGF‐β1‐induced fibrosis processes, we performed a proteomic analysis of TGF‐β1‐induced normal rat kidney cells exposed to ascofuranone (AF). In these cells, we detected 1500 proteins, with 74 differentially expressed proteins identified by MALDI‐TOF and reference to the NCBI and Swiss‐Prot databases, including PAI‐1, peroxisome prdifesator‐activated receptor, prohibitin, glutamate formyltransferase, LIM domain protein 1, LASP‐1, porphobilinogen deaminase, and peroxiredoxin 2. We also found that AF suppresses expression of profibrotic factors induced by TGF‐β in renal fibroblasts, including matrix proteins and PAI‐1. AF was also shown to inhibit selectively phosphorylation of epidermal growth factor receptor, and downstream kinases such as extracellular signal‐regulated kinase 1/2 (ERK‐1/2). Further ongoing analysis of fibrosis‐related proteins will determine AF's potential for application in fibrotic diseases and therapeutics. 相似文献
130.
Eun Hee Ahn Dae Won Kim Min Jea Shin Hye Ri Kim So Mi Kim Su Jung Woo Seon Ae Eom Hyo Sang Jo Duk-Soo Kim Sung-Woo Cho Jinseu Park Won Sik Eum Soo Young Choi 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014