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排序方式: 共有2868条查询结果,搜索用时 15 毫秒
1.
2.
Pasupathi Sundaramoorthy Jae Jun Sim Yeong-Su Jang Siddhartha Kumar Mishra Keun-Yeong Jeong Poonam Mander Oh Byung Chul Won-Sik Shim Seung Hyun Oh Ky-Youb Nam Hwan Mook Kim 《PloS one》2015,10(1)
Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK) plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca2+) supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca2+ bound lactate (CaLa), its downstream signaling and role in the motility of human colon cancer cells. We found that treating HCT116 and HT-29 cells with CaLa immediately increased the intracellular Ca2+ (iCa2+) levels for a prolonged period of time. Ca2+ influx induced cleavage of FAK into an N-terminal FAK (FERM domain) in a dose-dependent manner. Phosphorylated FAK (p-FAK) was also cleaved in to its p-N-terminal FAK. CaLa increased colon cancer cells motility. Calpeptin, a calpain inhibitor, reversed the effects of CaLa on FAK and pFAK cleavage in both cancer cell lines. The cleaved FAK translocates into the nucleus and modulates p53 stability through MDM2-associated ubiquitination. CaLa-induced Ca2+ influx increased the motility of colon cancer cells was mediated by calpain activity through FAK and pFAK protein destabilization. In conclusion, these results suggest that careful consideration may be given in deciding dietary Ca2+ supplementation to patient undergoing treatment for metastatic cancer. 相似文献
3.
Gwang Hoon Gil Seung Rim Kim Jong Chan Bae Jae Heung Lee 《Enzyme and microbial technology》1985,7(8):370-372
Effects of inoculum size and total sugar content on both l-phenylalanine productivity and titre have been investigated using a tyrosine auxotrophic regulatory mutant of Escherichia coli. Fermentations were carried out in a 500 litre pilot fermenter with intermittent feeding of d-glucose plus phosphate. It was found that the productivity was not greatly affected by inoculum size. However, the l-phenylalanine titre was significantly affected by total sugar content. Relatively high productivities of up to 0.35–0.40 g l-phenylalanine l?1 h?1 have been achieved at l-phenylalanine titres of 14–15 g l?1. 相似文献
4.
Panose, a major component of isomalto-oligosaccharides, was selectively produced from maltose using transglucosylation reaction catalyzed by intact cells of Aureobasidium pullulans. When 50 %(w/v) maltose was used as a substrate, the maximum concentration of panose accumulated in the final reaction mixture was about 50 %(w/w) after 120 hr reaction at 55 °C. 相似文献
5.
Summary A gene for allosteric lactate dehydrogenase (LDH) of Lactobacillus casei ATCC393 was transferred into Bacillus subtilis. The LDH was produced in a growth-associated type, and comprised up to 40 % of the total cellular protein. The maximum specific activity in the transformant was 208 U/mg protein which was approximately 16 times higher than in L. casei or in the previously constructed Escherichia coli transformant. 相似文献
6.
Summary In the production of L-cysteine from D,L-ATC stability of the relevant enzymes produced byPseudomonas sp. was tested, and strategies to improve the stability of L-ATC hydrolase were investigated in view of water activity and ionic strength. Among the three enzymes which participate in L-cysteine production, i.e., ATC racemase, L-ATC hydrolase, and S-carbamyl-L-cysteine hydrolase, L-ATC hydrolase is the least stable. Various mixtures of salts and sorbitol were added to adjust the water activities of the tested solutions. As water activity decreased from 0.93 to 0.80, the stability of L-ATC hydrolase was sharply enhanced. In the absence of sorbitol the stability of L-ATC hydrolase increased in proportion to ionic strength. Even though enzyme stability was not good at a low ionic strength, it was enhanced by lowering water activity with addition of sorbitol. The half life of L-ATC hydrolase in sorbitol-salt mixtures increased by tenfold to twentyfold compared to that of a control. 相似文献
7.
Seung B. Ha Neli Melman Kenneth A. Jacobson Vasu Nair 《Bioorganic & medicinal chemistry letters》1997,7(24):1698-3090
N6-Substituted adenosine analogues containing cyclic hydrazines or chiral hydroxy (ar)alkyl groups, designed to interact with the S2 and S3 receptor subregions, have been synthesized and their binding to the adenosine A1 and A2A receptors have been investigated. Examples of both types of compounds were found to exhibit highly selective binding (Ki in low nM range) to the rat A1 receptor. 相似文献
8.
Lab-scale study of an anaerobic membrane bioreactor (AnMBR) for dilute municipal wastewater treatment 总被引:1,自引:0,他引:1
Seung Hyuk Baek Krishna R. Pagilla Hyung-Jin Kim 《Biotechnology and Bioprocess Engineering》2010,15(4):704-708
Anaerobic bioreactors supplemented with membrane technology have become quite popular, owing to their favorable energy recovery
characteristics. In this study, a lab-scale anaerobic Membrane Bioreactor (AnMBR) was assessed in experimental treatments
of pre-settled dilute municipal wastewater obtained from a full-scaled wastewater treatment plant. The MBR system was operated
in continuous flow mode for 440 days. To evaluate the performance of the AnMBR under various loading rates, the hydraulic
retention time (HRT) was reduced in a stepwise manner (from 2 to 0.5 days). Afterward, the mixed liquor suspended solids (MLSS)
were reduced from 7,000 to 3,000 mg/L in increments of 1,000 mg/L, resulting in a decrease in solids retention time (SRT)
at a constant HRT of 1.0 day. The soluble chemical oxygen demand (SCOD) concentration in the feed varied between 38 and 131
mg/L, whereas the average permeate SCOD ranged between 18 and 37 mg/L, reflecting excellent effluent quality. The AnMBR performance
in terms of COD removal proved stable, despite variations in influent characteristics and HRT and SRT changes. The concentration
of extracellular polymeric substance (EPS) was reduced with decreases in HRT from 42 to 22 mg VS/mg of MLSS, thereby indicating
that the increased biomass concentration biodegraded the EPS at lower HRTs. AnMBR is, therefore, demonstrably a feasible option
for the treatment of dilute wastewater with separate stage nitrogen and phosphorus removal processes. 相似文献
9.
Seung U. Kim 《Histochemistry and cell biology》1976,48(3):205-217
Summary Explants of 10–12 day chick embryo spinal cord were cultured by coverslip-roller tube method for 3–80 days. The cellular and subcellular localization of acetylcholinesterase activity in cultured neurons was studied by the thiocholine techniques of Karnovsky and Roots and Lewis and Shute.At the light microscopic level, acetylcholinesterase was demonstrated in the neurons of both ventral and dorsal horn regions. Occasionally neurons migrated in the outgrowth zone exhibited strong intracellular activity.At the electron microscopic level, acetylcholinesterase activity was found in the nuclear envelope, granular endoplasmic reticulum and the Golgi apparatus of the neurons. No enzyme reaction was detected in the glial cell cytoplasm. 相似文献
10.
Abstract The syntheses of three classes of adenosine analogues involving cyclosubstitution at the 6-position and functionalization at the 2-position are reported. The target molecules synthesized are stable with respect to hydrolytic deamination by mammalian adenosine deaminase, and, because of major structural changes at the 2- and 6-positions, these compounds are expected to be poor phosphorylation substrates for the kinases. Adenosine receptor binding data reveal that several of the compounds synthesized show excellent A1 receptor affinity and A2/A1 selectivity. 相似文献