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171.
Background
Serum-containing medium (SCM), which has a number of poorly defined components with varying concentrations, hampers standardization of lymphocyte cultures. In order to develop a serum-free medium (SFM) for the expansion of human lymphocytes from peripheral blood mononuclear cells (PBMCs), a statistical optimization approach based on a fractional factorial method and a response surface method was adopted. A basal medium was prepared by supplementing RPMI1640 medium with insulin, albumin, ferric citrate, ethanolamine, fatty acids, glutamine, sodium pyruvate, 2-mercaptoethanol, 1-thioglycerol, nonessential amino acids, and vitamins. We identified additional positive determinants and their optimal concentrations for cell growth through a statistical analysis. 相似文献172.
173.
Je JY Kim EK Ahn CB Moon SH Jeon BT Kim B Park TK Park PJ 《International journal of biological macromolecules》2007,41(5):529-533
Prolyl endopeptidase (PEP, EC 3.4.21.26) is a proline-specific endopeptidase with a serine-type mechanism, which digests small peptide-like hormones, neuroactive peptides, and various cellular factors. PEP has been involved in neurodegenerative disorders, therefore, the discovery of PEP inhibitors can revert memory loss caused by amnesic compounds. In this study, we prepared hetero-chitooligosaccharides (COSs) with different molecular sizes using ultrafiltration (UF) membrane reactor system from hetero-chitosan with different degrees of deacetylation (DD; 90%, 75% and 50% deacetylation), and synthesized sulfated COSs (SCOSs). PEP inhibitory activities of SCOSs were evaluated and the results showed that 50% deacetylated SCOSs (50-SCOSs) exhibited higher inhibitory activities than those of 90% and 75% deacetylated SCOSs (90-SCOSs and 75-SCOSs). Among the 50-SCOSs (50-SCOS I, 5000–10,000 Da; 50-SCOS II, 1000–5000 Da; 50-SCOS III, below 1000 Da), 50-SCOS II possessed the highest inhibitory activity and IC50 value was 0.38 mg/ml. Kinetics studies with 50-SCOS II indicated a competitive enzyme inhibition with a Ki value of 0.78 mg/ml. It was concluded that the 50-SCOS II may be useful for PEP inhibitor and for developing a new type PEP inhibitor from carbohydrate based materials. 相似文献
174.
Lee DG Jeon JH Jang MK Kim NY Lee JH Lee JH Kim SJ Kim GD Lee SH 《Biotechnology letters》2007,29(3):465-472
A metagenomic library was constructed using total genomic DNA extracted from the mud in the west coast of Korea and was used
together with a fosmid vector, pCC1FOS in order to uncover novel gene sources. One clone from approximately 30,000 recombinant
Escherichia coli clones was identified that showed proteolytic activity. The gene for the proteolytic enzyme was subcloned into pUC19 and
sequenced, and a database search for homologies revealed it to be a zinc-dependent metalloprotease. The cloned gene included
the intact coding gene for a novel metalloproteinase and its own promoter. It comprised an open reading frame of 1,080 base
pairs, which encodes a protein of 39,490 Da consisting of 359 amino acid residues. A His-Glu-X-X-His sequence, which is a
conserved sequence in the active site of zinc-dependent metalloproteases, was found in the deduced amino acid sequence of
the gene, suggesting that the enzyme is a zinc-dependent metalloprotease. The purified enzyme showed optimal activity at 50°C
for 1 h and pH 7.0. The enzyme activity was inhibited by metal-chelating reagents, such as EDTA, EGTA and 1,10-phenanthroline.
The enzyme hydrolyzed azocasein as well as fibrin. Thus, the enzyme could be useful as a therapeutic agent to treat thrombosis.
The sequence reported in this paper has been deposited in the GenBank database (Accession number: EF100137). 相似文献
175.
Joo Mi Jeon Nam Young Ahn Bo Hwa Son Cha Young Kim Chang-deok Han Gun-Do Kim Sang Wan Gal Sung-Ho Lee 《Plant Cell, Tissue and Organ Culture》2007,88(2):225-232
PEG-mediated transformation was used for gene delivery and evaluation of various parameters affecting the transient expression of a gene for ß-glucuronidase (gus) in mesophyll protoplasts of Capsicum annuum. Transient expression was found to be dependent on PEG concentration and exposure time of plasmid DNA to protoplasts as well as the amount of plasmid DNA. Maximum GUS activity was obtained when protoplasts were applied to 40% concentration and molecular weight was 6,000 of PEG solution with 30 min of exposure time. Protoplasts of pepper were transformed with a vector, pCAMBIA::Ac, which contained a pCAMBIA1302 T-DNA vector carrying a maize transposable element, Ac (activator), a selection marker HPT (hygromycin phosphotransferase), and a GFP-coding region driven by the 35S promoter in the presence of PEG. Approximately 30% of the protoplasts expressed GFP. Visibly transformed colonies were obtained from protoplasts after 2 months of culture and GFP was expressed. Southern hybridization confirmed the presence of Ac in the pepper genome. 相似文献
176.
Kim YK Oh SY Jeon SG Park HW Lee SY Chun EY Bang B Lee HS Oh MH Kim YS Kim JH Gho YS Cho SH Min KU Kim YY Zhu Z 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(8):5375-5382
Allergic asthma is characterized by airway inflammation initiated by adaptive immune responses to aeroallergens. Recent data suggest that severe asthma may be a different form of asthma rather than an increase in asthma symptoms and that innate immune responses to LPS can modulate adaptive immune responses to allergens. In this study, we evaluated the hypothesis that airway exposure to different doses of LPS induces different form of asthma. Our study showed that neutrophilic inflammation and IFN-gamma expression were higher in induced sputum from severe asthma patients than from mild to moderate asthmatics. Animal experiments indicated that allergen sensitization with low-dose LPS (0.1 microg) induced type 2 asthma phenotypes, i.e., airway hyperresponsiveness, eosinophilic inflammation, and allergen-specific IgE up-regulation. In contrast, allergen sensitization with high-dose LPS (10 microg) induced asthma phenotypes, i.e., airway hyperresponsiveness and noneosinophilic inflammation that were not developed in IFN-gamma-deficient mice, but unaffected in the absence of IL-4. During the allergen sensitization period, TNF-alpha expression was found to be enhanced by both low- and high-dose LPS, whereas IL-12 expression was only enhanced by high-dose LPS. Interestingly, the asthma phenotypes induced by low-dose LPS, but not by high-dose LPS, were completely inhibited in TNF-alpha receptor-deficient mice, whereas the asthma phenotypes induced by high-dose LPS were abolished in the homozygous null mutation of the STAT4 gene. These findings suggest that airway exposure levels of LPS induces different forms of asthma that are type 1 and type 2 asthma phenotypes by high and low LPS levels, respectively. 相似文献
177.
Kang MA Jeoung NH Kim JY Lee JE Jung UJ Choi MS Lee WH Kwon OS Lee H Park YB 《Life sciences》2007,80(5):460-467
Changes in the expression level of the skeletal muscle LIM protein 1 (SLIM1) in cultured A10 cells were monitored in response to 25-hydroxycholesterol (25-HC), an oxidized form of cholesterol present in the oxidized low-density lipoproteins. The level of SLIM1 mRNA was elevated in a time- and concentration-dependent manner by treatment of 25-HC. Expressions of smooth muscle (SM) alpha-actin and calponin-1 (CNN-1), early markers for SMC differentiation, were also increased by the 25-HC treatments. Expressions of all three genes (SLIM1, SM alpha-actin and CNN-1) were simultaneously elevated in the cells treated with 9-cis retinoic acid (RA). On the other hand, the SLIM1 expression induced by the 25-HC or 9-cis RA (as well as SM alpha-actin and CNN-1) was decreased by the treatment of 15d-PGJ2. Since the 25-HC, 9-cis RA and 15d-PGJ2 were ligands for the LXR, RXRalpha and PPARgamma respectively, there might be a functional positive cross-talk between LXR and RXRalpha pathways and a negative cross-talk between PPARgamma and LXR and/or RXRalpha pathways in the regulation of SLIM1 expression. The cells stably transfected with the expressional vector for SLIM1 also showed an elevation in the levels of SM alpha-actin and CNN-1. In addition, an over-production of SLIM1 in the cells resulted in a change in the cell-shape into a spindle-like form, which is identical to that observed after a prolonged treatment of the cells with cholesterol. 相似文献
178.
179.
Kim JI Jeon SB Baek I Seok YM Shin HM Kim IK 《Biochemical and biophysical research communications》2007,356(3):718-722
Our previous study demonstrated that heat shock augmented vascular contraction. In the present study, we hypothesized that heat shock augments myosin phosphatase target-subunit (MYPT1) phosphorylation resulting in augmented vascular contraction. Endothelium-denuded rat aortic rings were mounted in organ baths, exposed to heat shock (42 degrees C for 45 min), and subjected to contraction 4 h after the heat shock followed by Western blot analysis for MLC(20) (the 20 kDa light chains of myosin II) or MYPT1. The contractile responses in both control and heat shock-treated aorta were inhibited by Y27632, an inhibitor of Rho-kinase. The level of the MLC(20) and MYPT1(Thr855) phosphorylation in response to KCl was higher in heat shock-treated aorta than that in timed-control. The increased MYPT1(Thr855) phosphorylation was inhibited by Y27632 (1.0 microM) in parallel with inhibition of MLC(20) phosphorylation and vascular contraction. These results indicate that heat shock augments MYPT1 phosphorylation resulting in augmented vascular contraction. 相似文献
180.
Hox genes are important in forming the anterior-posterior body axis pattern in the early developmental stage of animals. The
conserved nature of the genomic organization of Hox genes is well known in diverse metazoans. To understand the Hox gene architecture
in human-infecting Taenia tapeworms, we conducted a genomic survey of the Hox gene using degenerative polymerase chain reaction primers in Taenia asiatica. Six Hox gene orthologs from 276 clones were identified. Comparative analysis revealed that T. asiatica has six Hox orthologs, including two lab/Hox1, two Hox3, one Dfd/Hox4, and one Lox2/Lox4. The results suggest that Taenia Hox genes may have undergone independent gene duplication in two Hox paralogs. The failure to detect Post1/2 orthologs in
T. asiatica may suggest that sequence divergence or the secondary loss of the posterior genes has occurred in the lineage leading to
the cestode and trematode. 相似文献