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21.
Yoshiaki Fujimiya Youichi Suzuki Ko-ichi Oshiman Hidekazu Kobori Koichi Moriguchi Hisako Nakashima Yonezo Matumoto Shogo Takahara Takusaburo Ebina Ryuichi Katakura 《Cancer immunology, immunotherapy : CII》1998,46(3):147-159
We have isolated a novel type of natural tumoricidal product from the basidiomycete strain, Agaricus blazei Murill. Using the double-grafted tumor system in Balb/c mice, treatment of the primary tumor with an acid-treated fraction
(ATF) obtained from the fruit bodies resulted in infiltration of the distant tumor by natural killer (NK) cells with marked
tumoricidal activity. As shown by electrophoresis and DNA fragmentation assay, the ATF also directly inhibited tumor cell
growth in vitro by inducing apoptotic processing; this apoptotic effect was also demonstrated by increased expression of the
Apo2.7 antigen on the mitochondrial membranes of tumor cells, as shown by flow-cytometric analysis. The ATF had no effect
on normal mouse splenic or interleukin-2-treated splenic mononuclear cells, indicating that it is selectively cytotoxic for
the tumor cells. Cell-cycle analysis demonstrated that ATF induced the loss of S phase in MethA tumor cells, but did not affect
normal splenic mononuclear cells, which were mainly in the G0G1 phase. Various chromatofocussing purification steps and NMR
analysis showed the tumoricidal activity to be chiefly present in fractions containing (1→4)-α-D-glucan and (1→6)-β-D-glucan, present in a ratio of approximately 1:2 in the ATF (molecular mass 170 kDa), while the final purified fraction, HM3-G
(molecular mass 380 kDa), with the highest tumoricidal activity, consisted of more than 90% glucose, the main component being
(1→4)-α-D-glucan with (1→6)-β branching, in the ratio of approximately 4:1.
Received: 27 August 1997 / Accepted 22 December 1997 相似文献
22.
23.
Fukasawa A Nagashima T Aoyama T Fukuda N Matsuda H Ueno T Sugiyama H Nagase H Matsumoto Y 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,859(2):272-275
A simple and sensitive high-performance liquid chromatography (HPLC) method utilizing UV detection was developed for the determination of plasma pyrrole (Py)-imidazole (Im) polyamides in rats and applied to the pharmacokinetic study of compounds. After deproteinization of plasma with methanol, Py-Im polyamides were analyzed with a reversed-phase TSK-GEL ODS-80TM (4.6 mmx15.0 cm TOSOH Co., Japan) column maintained at 40 degrees C. The mobile phase solvent A was 0.1% acetic acid and the solvent B was HPLC-grade acetonitrile (0-10 min, A: 100-20%, B: 0-80% linear gradient; 10-15 min, A: 40%, B: 60%). The flow rate was 1.0 ml/min. The detection wavelength was set at 310 nm. The method was used to determine the plasma concentration time profiles of Py-Im polyamides after intravenous injection. 相似文献
24.
Nakatani K Horie S Goto Y Kobori A Hagihara S 《Bioorganic & medicinal chemistry》2006,14(15):5384-5388
Drugs targeting the stem-loop IIB of Rev responsible element (RRE) of HIV-1 mRNA are potential therapeutic agents for HIV-1 infection. The stem loop is characterized by an internal loop consist of consecutive G-G and G-A mismatches, which is the single binding site for Rev protein for nuclear export of viral mRNA. We report here that ligands binding to G-G and G-A mismatches in duplex DNA also bind to the internal loop in competition with Rev peptide and lead to the dissociation of pre-formed Rev-RRE complex in a model system. 相似文献
25.
Takeyasu K Kim J Ohniwa RL Kobori T Inose Y Morikawa K Ohta T Ishihama A Yoshimura SH 《Cytogenetic and genome research》2004,107(1-2):38-48
The proper function of the genome largely depends on the higher order architecture of the chromosome. Our previous application of nanotechnology to the questions regarding the structural basis for such macromolecular dynamics has shown that the higher order architecture of the Escherichia coli genome (nucleoid) is achieved via several steps of DNA folding (Kim et al., 2004). In this study, the hierarchy of genome organization was compared among E. coli, Staphylococcus aureus and Clostridium perfringens. A one-molecule-imaging technique, atomic force microscopy (AFM), was applied to the E. coli cells on a cover glass that were successively treated with a detergent, and demonstrated that the nucleoids consist of a fundamental fibrous structure with a diameter of 80 nm that was further dissected into a 40-nm fiber. An application of this on-substrate procedure to the S. aureus and the C. perfringens nucleoids revealed that they also possessed the 40- and 80-nm fibers that were sustainable in the mild detergent solution. The E. coli nucleoid dynamically changed its structure during cell growth; the 80-nm fibers releasable from the cell could be transformed into a tightly packed state depending upon the expression of Dps. However, the S. aureus and the C. perfringens nucleoids never underwent such tight compaction when they reached stationary phase. Bioinformatic analysis suggested that this was possibly due to the lack of a nucleoid protein, Dps, in both species. AFM analysis revealed that both the mitotic chromosome and the interphase chromatin of human cells were also composed of 80-nm fibers. Taking all together, we propose a structural model of the bacterial nucleoid in which a fundamental mechanism of chromosome packing is common in both prokaryotes and eukaryotes. 相似文献
26.
Analyses of non-leucine-rich repeat (non-LRR) regions intervening between LRRs in proteins 总被引:1,自引:0,他引:1
Norio Matsushima Tomoko Mikami Takanori Tanaka Hiroki Miyashita Keiko Yamada Yoshio Kuroki 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Background
Many proteins have LRR (leucine-rich repeat) units interrupted by non-LRRs which we call IR (non-LRR island region).Methods
We identified proteins containing LRR@IRs (LRRs having IR) by using a new method and then analyzed their natures and distributions.Results
LRR@IR proteins were found in over two hundred proteins from prokaryotes and from eukaryotes. These are divided into twenty-one different protein families. The IRs occur one to four times in LRR regions and range in length from 5 to 11,265 residues. The IR lengths in Fungi adenylate cyclases (acys) range from 5 to 116 residues; there are 22 LRR repeats. The IRs in Leishmania proteophosphoglycans (ppgs) vary from 105 to 11,265 residues. These results indicate that the IRs evolved rapidly. A group of LRR@IR proteins—LRRC17, chondroadherin-like protein, ppgs, and four Pseudomonas proteins—have a super motif consisting of an LRR block and its adjacent LRR@IR region. This indicates that the entire super motif experienced duplication. The sequence analysis of IRs offers functional similarity in some LRR@IR protein families.General significance
This study suggests that various IRs and super motifs provide a great variety of structures and functions for LRRs. 相似文献27.
Hidehiko Kumagai Hideyuki Suzuki Hiroki Shigematsu Tatsurokuro Tochikura 《Bioscience, biotechnology, and biochemistry》2013,77(9):2481-2487
An enzyme that catalyzes the synthesis of S-carboxymethyl- l-cysteine from 3-chloro- l-alanine (3-Cl-Ala) and thioglycolic acid was found in Escherichia coli W3110 and was designated as S- carboxymethyl-l-cysteine synthase. It was purified from the cell-free extract to electrophoretic homogeneity and was crystallized. The enzyme has a molecular weight of 84,000 and gave one band corresponding to a molecular weight of 37,000 on SDS-polyacrylamide gel electrophoresis. The purified enzyme catalyzed the β-replacement reactions between 3-CI-AIa and various thiol compounds. The apparent Km values for 3-Cl-Ala and thioglycolic acid were 40 mM and 15.4 mM. The enzyme showed very low activity as to the α,β-elimination reaction with 3-Cl-Ala and l-serine. It was not inactivated on the incubation with 3-Cl-Ala. The absorption spectrum of the enzyme shows a maximum at 412 nm, indicating that it contains pyridoxal phosphate as a cofactor. The N-terminal amino acid sequence was determined and the corresponding sequence was detected in the protein sequence data bank, but no homogeneous sequence was found. 相似文献
28.
Ki-Sung Kim Yuichiro Arima Taro Kitazawa Koichi Nishiyama Rieko Asai Yasunobu Uchijima Takahiro Sato Giovanni Levi Sachiko Kitanaka Takashi Igarashi Yukiko Kurihara Hiroki Kurihara 《Mechanisms of development》2013,130(11-12):553-566
Endothelin-1 (Edn1), originally identified as a vasoconstrictor peptide, is involved in the development of cranial/cardiac neural crest-derived tissues and organs. In craniofacial development, Edn1 binds to Endothelin type-A receptor (Ednra) to induce homeobox genes Dlx5/Dlx6 and determines the mandibular identity in the first pharyngeal arch. However, it remains unsolved whether this pathway is also critical for pharyngeal arch artery development to form thoracic arteries. Here, we show that the Edn1/Ednra signaling is involved in pharyngeal artery development by controlling the fate of neural crest cells through a Dlx5/Dlx6-independent mechanism. Edn1 and Ednra knock-out mice demonstrate abnormalities in pharyngeal arch artery patterning, which include persistent first and second pharyngeal arteries, resulting in additional branches from common carotid arteries. Neural crest cell labeling with Wnt1-Cre transgene and immunostaining for smooth muscle cell markers revealed that neural crest cells abnormally differentiate into smooth muscle cells at the first and second pharyngeal arteries of Ednra knock-out embryos. By contrast, Dlx5/Dlx6 knockout little affect the development of pharyngeal arch arteries and coronary arteries, the latter of which is also contributed by neural crest cells through an Edn-dependent mechanism. These findings indicate that the Edn1/Ednra signaling regulates neural crest differentiation to ensure the proper patterning of pharyngeal arch arteries, which is independent of the regional identification of the pharyngeal arches along the dorsoventral axis mediated by Dlx5/Dlx6. 相似文献
29.
Murai H Qi H Choudhury B Wild J Dharajiya N Vaidya S Kalita A Bacsi A Corry D Kurosky A Brasier A Boldogh I Sur S 《PloS one》2012,7(2):e30280
Background
A series of epidemiologic studies have identified the fungus Alternaria as a major risk factor for asthma. The airway epithelium plays a critical role in the pathogenesis of allergic asthma. These reports suggest that activated airway epithelial cells can produce cytokines such as IL-25, TSLP and IL-33 that induce Th2 phenotype. However the epithelium-derived products that mediate the pro-asthma effects of Alternaria are not well characterized. We hypothesized that exposure of the airway epithelium to Alternaria releasing cytokines that can induce Th2 differentiation.Methodology/Principal Finding
We used ELISA to measure human and mouse cytokines. Alternaria extract (ALT-E) induced rapid release of IL-18, but not IL-4, IL-9, IL-13, IL-25, IL-33, or TSLP from cultured normal human bronchial epithelial cells; and in the BAL fluids of naïve mice after challenge with ALT-E. Both microscopic and FACS indicated that this release was associated with necrosis of epithelial cells. ALT-E induced much greater IL-18 release compared to 19 major outdoor allergens. Culture of naïve CD4 cells with rmIL-18 induced Th2 differentiation in the absence of IL-4 and STAT6, and this effect was abrogated by disrupting NF- κB p50 or with a NEMO binding peptide inhibitor.Conclusion/Significance
Rapid and specific release of IL-18 from Alternaria-exposed damaged airway epithelial cells can directly initiate Th2 differentiation of naïve CD4+ T-cells via a unique NF-κB dependent pathway. 相似文献30.
Theoretical results on the geometric and electronic structures of some donor-acceptor polymers based on polythiophene (X=S), polyfuran (X=O) and polypyrrole (X=NH) were obtained, using a one-dimensional tight-binding self-consistent field crystal-orbital (SCF-CO) method at the MNDO-AM1 level of approximation. The repeat unit of these polymers consits of a bithiophene, furan or bipyrrole unit bridged by an electron-accepting group or. The optimized geometries of the polymers show a strong dependence on the nature of the electron donating group X. All the polymers studied are predicted to have band gap values ranging between 1 eV and 2 eV. An analysis of their -bond order data and of the patterns of their frontier orbitals shows they have benzenoid-like electronic structures. 相似文献