排序方式: 共有19条查询结果,搜索用时 46 毫秒
1.
Tian Lan Huichang Bi Suowen Xu Kang Le Zhiyong Xie Yiwei Liu Heqing Huang 《Biomedical chromatography : BMC》2010,24(10):1075-1083
Sphingosine kinase (SphK) is a key enzyme in modulating the levels of sphingosine 1‐phosphate (S1P) as well as an important enzyme in numerous biological responses. Using C17‐sphingosine as a substrate, we established a rapid, sensitive and highly efficient method for determination of SphK activity by analyzing the product C17‐sphingosine 1‐phosphate (C17‐S1P) using liquid chromatography–tandem mass spectrometry. The standard curve for C17‐S1P was linear over a wide range (10–1000 ng/mL) with correlation coefficient (r2) greater than 0.999. The lower limit of quantification for C17‐S1P was 10 ng/mL. The Km values for C17‐sphingosine and ATP were determined to be 28.17 and 188.5 mM, respectively. More importantly, the SphK activity dramatically increased in cultured HEK 293 cells expressing wild‐type SphK1 as well as cells treated with tumor necrosis factor‐a, a sphingosine kinase activator. In contrast, the SphK activity decreased in cultured HEK 293 cells treated with dimethylsphngosine, a sphingosine kinase inhibitor. In conclusion, this method was sensitive and rapid in the determination of SphK acitivity, providing striking utilities in exploring the sphingosine kinase signaling pathway and screening active compounds targeting SphK activity. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
2.
A New Ceramide from the Soft Coral Cladiella humesi Verseveldt 总被引:2,自引:0,他引:2
Ming Yan WANG Yi LUO Jing Yu SU Department of Chemistry Zhongshan University Guangzhou 《中国化学快报》2000,11(9)
Ceramides are increasingly becoming important compounds because of their markedbiological activity. The 2000 International Gordon Research Conference on "Glycolipidand Sphingolipid Biology" will be held in May in italy. It has been recently found thatceramides inhibit Cholesteryl Ester Transfer Protein (CETP)'. Elevation in CETP leadsto atherosclerotic cardiovascular diseases2. A literature survey showed that ceramideswere antifungal', and some of these showed antimicrobial and cytotox… 相似文献
3.
Inside Cover: Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid Ceramidase (Angew. Chem. Int. Ed. 2/2015) 下载免费PDF全文
4.
Sphingosylphosphorylcholine (SPC) induces differentiation of human adipose tissue-derived mesenchymal stem cells (hASCs) into smooth muscle-like cells expressing α-smooth muscle actin (α-SMA) via transforming growth factor-β1/Smad2- and RhoA/Rho kinase-dependent mechanisms. 3-Hydroxy-3-methylglutaryl- coenzyme A reductase inhibitors (statins) have been known to have beneficial effects in the treatment of cardiovascular diseases. In the present study, we examined the effects of simvastatin on the SPC-induced α-SMA expression and Smad2 phosphorylation in hASCs. Simvastatin inhibited the SPC-induced α-SMA expression and sustained phosphorylation of Smad2 in hASCs. SPC treatment caused RhoA activation via a simvastatin-sensitive mechanism. The SPC-induced α-SMA expression and Smad2 phosphorylation were abrogated by pretreatment of the cells with the Rho kinase inhibitor Y27632 or overexpression of a dominant negative RhoA mutant. Furthermore, SPC induced secretion of TGF-β1 and pretreatment with either Y27632 or simvastatin inhibited the SPC-induced TGF-β1 secretion. These results suggest that simvastatin inhibits SPC-induced differentiation of hASCs into smooth muscle cells by attenuating the RhoA/Rho kinase-dependent activation of autocrine TGF-β1/Smad2 signaling pathway. 相似文献
5.
高效液相色谱法测定人尿中神经鞘氨醇和二氢神经鞘氨醇 总被引:2,自引:0,他引:2
建立了一种检测人尿中神经鞘氨醇(So)和二氢神经鞘氨醇(Sa)的高效液相色谱方法(HPLC)。离心分离尿样中的片状剥落细胞,裂解后用乙酸乙酯萃取、邻苯二甲醛衍生,在HPLC系统中通过梯度洗脱用Nova-PakC18-RP色谱柱(15cm×3.9mm,4μm)分离、荧光检测器检测。So和Sa的检出限均为0.05ng(女性尿样0,075μg/L、男性尿样0.005μg/L)。分析从我国一个村在采集的40份尿样,女性尿样中So、Sa和Sa/So比值分别为1.29-13.58μg/L、0.25-3.13μg/L和0.15-0.25,男性尿样中分别为0.075~3.07μg/L、0.019-0.50μg/L和0.028~0.26。 相似文献
6.
The sphingosine kinase 1 (SK1)/sphingosine-1-phosphate (S1P) signaling pathway is a crucial target for numerous human diseases from cancer to cardiovascular diseases. However, available SK1 inhibitors that target the active site suffer from poor potency, selectivity and pharmacokinetic properties. The selectivity issue of the kinases, which share a highly-conserved ATP-pocket, can be overcome by targeting the less-conserved allosteric sites. SK1 is known to function minimally as a dimer; however, the crystal structure of the SK1 dimer has not been determined. In this study, a template-based algorithm implemented in PRISM was used to predict the SK1 dimer structure and then the possible allosteric sites at the dimer interface were determined via SiteMap. These sites were used in a virtual screening campaign that includes an integrated workflow of structure-based pharmacophore modeling, virtual screening, molecular docking, re-screening of common scaffolds to propose a series of compounds with different scaffolds as potential allosteric SK1 inhibitors. Finally, the stability of the SK1-ligand complexes was analyzed by molecular dynamics simulations. As a final outcome, ligand 7 having a 4,9-dihydro-1H-purine scaffold and ligand 12 having a 2,3,4,9-tetrahydro-1H-β-carboline scaffold were found to be potential selective inhibitors for SK1. 相似文献
7.
8.
9.
Summary A rapid, sensitive and selective high-performance liquid chromatographic method has been developed for the determination of
sphingosine in human serum. After precipitation with methanol, the samples were extracted using Carbopack B disposable columns;
the sphingosine was eluted with 0.05 M hydrochloric acid in methanol-dichloromethane (20∶80, v/v) and the extract evaporated
to dryness at 40°C. The sample residue was then reconstituted with methanol and reacted with o-phthaldialdehyde reagent to
produce a fluorescent compound. Separation was performed using an LC-18 column with 0.05 M phosphate buffer (pH 7)-methanol-acetonitrile
(15∶80∶5, v/v) as mobile phase. Fluorescence detection was performed with excitation and emission wavelengths of 340 and 455
nm, respectively. The serum extract was re-analyzed with a cyano LC column to minimize the possibility of false positive results.
The possible interference of compounds having a structure similar to that of sphingosine was evaluated. The mean recovery
of sphingosine was >94.5%. The limit of detection of the assay was 1 ng mL−1. The between-run and within-run coefficients of variation for replicate analyses were <4.0% and <3.4%, respectively. The
levels of free sphingosine in the serum of 40 normal subjects (20 male and 20 female) was investigated; the average level
was 81.6±41.1 ng mL−1 (mean ±S.D.) for males and 85.5±33.7 ng mL−1 for females. 相似文献
10.
2-Azetidinones were smoothly transformed to unsaturated ketones through the ring opening of activated 2-azetidinone by phosphonate stabilized carbanion and subsequent Horner–Wadsworth–Emmons olefination of the resulting β-ketophosphonates with aldehydes. A formal synthesis of l-erythro-sphingosine and d-lyxo-phytosphingosine from readily available 2-azetidinone was established utilizing this methodology. 相似文献