The study was aimed to characterize the probiotic properties of Lactobacillus paracasei subsp. paracasei strain KNI9 and its antagonistic activity against Yersinia enterocolitica subsp. enterocolitica. The strain KNI9 was susceptible to antibiotics such as chloramphenicol, tetracycline, erythromycin, and streptomycin recommended by European food safety authority (EFSA). Strain KNI9 exhibited tolerance to simulated oro-gastrointestinal (OGT) condition, adherence to Caco-2 cells, and antimicrobial activity against intestinal enteric pathogens such as Yersinia enterocolitica subsp. enterocolitica, Shigella boydii, and Listeria monocytogenes. Furthermore, the strain KNI9 inhibited the adherence and invasiveness of Y. enterocolitica subsp. enterocolitica to Caco-2 cell line. These results indicate that the L. paracasei subsp. paracasei KNI9 could be further developed into a potential probiotic strain after appropriate in vivo studies.
The chimeric oncoprotein BCR-Abl exhibits deregulated protein tyrosine kinase activity and is responsible for the pathogenesis of certain human leukemias, such as chronic myelogenous leukemia. The activities of cellular Abl (c-Abl) and BCR-Abl are stringently regulated and the cellular mechanisms involved in their inactivation are poorly understood. Protein tyrosine phosphatases can negatively regulate Abl mediated signaling by dephosphorylating the kinase and/or its substrates. This study investigated the ability of the intracellular T cell protein tyrosine phosphatase (TCPTP/PTPN2) to dephosphorylate and regulate the functions of BCR-Abl and c-Abl. TCPTP is expressed as two alternately spliced isoforms — TC48 and TC45, which differ in their C-termini and localize to the cytoplasm and nucleus respectively. We show that TC48 dephosphorylates BCR-Abl but not c-Abl and inhibits its activity towards its substrate, CrkII. Y1127 and Y1294 residues whose phosphorylation corresponds with BCR-Abl activation status were the primary sites targeted by TC48. Co-localization and immunoprecipitation experiments showed that TC48 interacted with BCR-Abl but not with c-Abl, and BCR domain was sufficient for interaction. TC48 expression resulted in the stabilization of Bcr-Abl protein dependent on its phosphatase activity. Inactivation of cellular TC48 in K562 cells by stable expression of a dominant negative catalytically inactive mutant TC48, enhanced proliferation. TC48 expressing K562 clones showed reduced proliferation and enhanced sensitivity to STI571 compared to control clones suggesting that TC48 can repress the growth of CML cells. This study identifies a novel cellular regulator that specifically inhibits the activity of oncogenic BCR-Abl but not that of the cellular Abl kinase. 相似文献
To investigate the anti-cancer properties of soil-borne actinobacteria, MJM 8637, the glutathione S-transferase pi (GST-pi) assay, anti-tumor necrosis factor (TNF)-α assay, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined. The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 8637, which was isolated from Hambak Mountain, Korea, has 99.5% similarity to Streptomyces atratus strain NBRC 3897. The physiological and the morphological characteristics of the strain MJM 8637 were also identified. The ethyl acetate extract of MJM 8637 inhibited TNF-α production approximately 61.8% at concentration 100 μg/ml. The IC50 value of the strain MJM 8637 extract on GST-pi was identified to be 120.2 ± 1.6 μg/ml. In DPPH, NO, and ABTS radical scavenging assays, the IC50 values of the strain MJM 8637 extract were found to be 977.2 μg/ml, 1143.7 μg/ml, and 454.4 μg/ml, respectively. The ethyl acetate extract of the strain MJM 8637 showed 97.2 ± 1.3% of cell viability at 100 μg/ml in RAW 264.7 cell viability assay. The results obtained from this study suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 8637 could be considered as a potential source of drug for the cancers that have multidrug resistance with its GST-pi inhibition and anti-inflammation activities, and low cytotoxicity. 相似文献
Based on a five level central composite design (CCD) involving the variables substrate concentration (C), pH (P), incubation temperature (T) and fermentation time (H), a response surface methodology (RSM) for the production of ethanol from pretreated sugarcane bagasse by cellulase and yeast Kluyveromyces fragilis was standardized. The design contains a total of 31 experimental trials in which the first 24 organized in a factorial design and from 25 to 31 involving the replications of the central points. Data obtained from RSM on ethanol production were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation. Maximum ethanol concentration (32.6 g/l) was obtained from 180 g/l pretreated sugarcane bagasse at the optimized process conditions (temperature 35°C, pH 5.5) in 72 h aerobic batch fermentation. Various kinetic models such as logistic model, logistic incorporated leudeking piret model and logistic incorporated modified leudeking piret model have been evaluated and the constants were predicted. 相似文献
Tricyclic sulfones were designed as γ-secretase inhibitors and found to have excellent potency. Extensive SAR shows that a large number of sulfonamides at position 7 of the tricycle are very well tolerated. Compounds such as 15a and 15c showed remarkable in vivo potency. 相似文献
The methanolic extract of the aerial part of Hedyotis corymbosa (L.) Lam. (Rubiaceae) was screened for antioxidant activity using 1,1-diphenyl-2-picryl hydroxyl (DPPH) quenching assay, 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid (ABTS) cation decolorization test, ferric reducing power (FRP), scavenging capacity towards hydroxyl ion (OH*) radicals and nitric oxide (NO) radical inhibition activity using established assay procedures. Total phenolics and total flavonoid contents were, also determined. The plant yielded 210 mg gallic acid equivalent/100 g phenolic content and 55 mg quercetin equivalent/100 g flavonoid content. The extract exhibited high antiradical activity against DPPH, ABTS, nitric oxide and hydroxyl radicals with EC50 value of 82, 150, 130, and 170 microg/ml, respectively. The FRP increased with increasing concentration of the sample. The antioxidant activity of the extract was comparable with that of the standard butylated hydroxyl toluene (BHT). High correlation between total phenolic/flavonoid contents and scavenging potential of different reactive oxygen species (R2 = 0.785-0.998) indicated the polyphenols as the main antioxidants. 相似文献
Turmeric and ginger are used as spices and in alternative systems of medicine. They are rich in polysaccharides, polyphenols,
and alkaloids. A simple and rapid method for isolating good quality DNA with fairly good yields from mature rhizome tissues
of turmeric and ginger has been perfected. Isolated DNA was amenable to restriction digestion and PCR amplification. 相似文献
Paramagnetic versions of the CLEAR supports were prepared by entrapment of magnetite particles during suspension polymerization
of allylamine, trimethylolpropane ethoxylate (14/3 EO/OH) triacrylate, and trimethylolpropane trimethacrylate. Swelling studies
in a broad range of solvents showed comparable swelling of magnetic beads and regular CLEAR beads. The application of the
magnetic beads as the support in solid-phase synthesis of peptides (Leu-enkephalinamide, substance P, acyl carrier protein
(65–74) amide, and amyloid β-protein (34–42) amide) and small organic affinity ligands based on the s-triazine scaffold was
demonstrated. Adequate stability of the beads and retention of their magnetic properties were observed throughout the synthesis
steps.
Abbreviations used for amino acids follow the IUPAC-IUB Commission of Biochemical Nomenclature (Jones, J. Pept. Sci., 12 (2006) 1). All amino acids used were of the L-configuration unless otherwise stated. All solvent ratios are volume/volume.
A preliminary report of portions of this work was presented at the 19th American Peptide Symposium in San Diego, CA, 2005
(Sasikumar and Kempe, 2006).
Dedicated to the memory of Bruce Merrifield (July 15, 1921–May 14, 2006). 相似文献