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991.
Chizuru Akatsu Duriya Fongmoon Shuji Mizumoto Jean-Claude Jacquinet Prachya Kongtawelert Shuhei Yamada Kazuyuki Sugahara 《Glycoconjugate journal》2010,27(4):387-399
Glycosaminoglycans (GAGs) like chondroitin sulfate (CS) and heparan sulfate (HS) are synthesized on the tetrasaccharide linkage
region, GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser, of proteoglycans. The Xyl can be modified by 2-O-phosphate in both CS and HS, whereas the Gal residues can be sulfated at C-4 and/or C-6 in CS but not in HS. To study the
roles of these modifications, monoclonal antibodies were developed against linkage glycopeptides of shark cartilage CS proteoglycans,
and one was characterized in detail. This antibody bound hexa- and pentasaccharide-peptides more strongly than unsaturated
tetrasaccharide-peptides with the unnatural fourth sugar residue (unsaturated hexuronic acid), suggesting the importance of
the fifth and/or fourth saccharide residue GalNAc-5 and/or GlcA-4. Its reactivity was not affected by treatment with chondro-4-sulfatase
or alkaline phosphatase, suggesting that 4-O-sulfate on the Gal residues and 2-O-phosphate on the Xyl residue were not recognized. Treatment with weak alkali to cleave the Xyl-Ser linkage completely abolished
the binding activity, suggesting the importance of the peptide moiety of the hexasaccharide-peptide for the binding. Based
on the amino acid composition and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analyses, it
was revealed that the peptide moiety is composed of four amino acids, Ser, Pro, Gly, and Glu. Furthermore, the antibody stained
wild-type CHO cells significantly, but much weakly mutant cells deficient in xylosyl- or galactosyltransferase-I required
for the biosynthesis of the linkage region. These results suggest that the antibody recognizes the structure GalNAc(±6-O-sulfate)-GlcA-Gal-Gal-Xyl-Ser-(Pro, Gly, Glu). The antibody will be a useful tool for investigating the significance of the
linkage region in the biosynthesis and/or intracellular transport of different GAG chains especially since such tools to study
the linkage region are lacking. 相似文献
992.
993.
Duk-Young Jung Takashi Yamada Toshie Tsuchiya Su-Chak Ryu Dong-Wook Han 《Biotechnology and Bioprocess Engineering》2010,15(2):341-348
Many studies have been performed to accelerate osteoinduction and osteoconduction into porous ceramic scaffolds by seeding
them with cells. In this study, we compared available cell-seeding methods on a porous β-tricalcium phosphate (β-TCP) scaffold
and evaluated the effects of cell-seeding on the mechanical properties of the porous β-TCP scaffold. Three types of porous
bioceramic scaffolds were used: dry scaffold, scaffold wetted with media, and scaffold cultivated with normal human osteoblasts
(NHOs). Cell-seeding into the porous β-TCP scaffolds was performed by conventional, centrifuge, high-density, and vacuum methods.
After confirming cell proliferation with MTT assay and cell staining, a compressive test was performed after 2 and 4 weeks
of cell culture. The vacuum method based on the high-density cell culture inserted effectively NHOs into the β-TCP scaffolds.
The compressive elastic modulus of wetted β-TCP scaffolds decreased significantly (p < 0.05) about 20∼30% after 2 and 4 weeks of incubation in comparison with that of the dry scaffold. However, the compressive
strength of the scaffolds cultivated with NHOs for 3 weeks was significantly (p < 0.05) higher than that of scaffolds without NHOs. The vacuum with the high-density of cell-seeding seems to be a suitable
method for seeding cells into complex porous ceramic scaffolds. Cell proliferation and uniform distribution in the scaffolds
can change the initial mechanical properties of porous ceramic scaffolds. 相似文献
994.
995.
Takaaki Yamada Nobuaki Egashira Maiko Imuta Takahisa Yano Yui Yamauchi Hiroyuki Watanabe Ryozo Oishi 《Free radical biology & medicine》2010,48(1):120-127
Vinorelbine (VNR), a vinca alkaloid anticancer drug, often causes vascular injury such as venous irritation, vascular pain, phlebitis, and necrotizing vasculitis. The purpose of this study was to identify the mechanisms that mediate the cell injury induced by VNR in porcine aorta endothelial cells (PAECs). PAECs were exposed to VNR for 10 min followed by further incubation in serum-free medium without VNR. The exposure to VNR (0.3–30 μM) decreased the cell viability concentration and time dependently. The incidence of apoptotic cells significantly increased at 12 h after transient exposure to VNR. At the same time, VNR increased the activity of caspases. Interestingly, VNR rapidly depleted intracellular glutathione (GSH) and increased intracellular reactive oxygen species (ROS) production. Moreover, VNR depolarized the mitochondrial membrane potential and decreased cellular ATP levels. These VNR-induced cell abnormalities were almost completely inhibited by GSH and N-acetylcysteine. On the other hand, l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH synthesis, aggravated the VNR-induced loss of cell viability. These results clearly demonstrate that VNR induces oxidative stress by depleting intracellular GSH and increasing ROS production in PAECs, and oxidative stress plays an important role in the VNR-induced cell injury. 相似文献
996.
A correlation between the quantitative changes in L-methionine analogs, the ratio of D-serine/L-serine during the pupal stage, and metamorphosis was observed. The glycoside appearing at low blood sugar values during the pupal stage was isolated and characterized as D-glucosyl-L-tyrosine. (1)H-NMR indicated the appearance and increase of this glycoside, and Mirrorcle Ray CV4 equipment was used to take X-ray pictures of the pupal bodies. The results indicate that γ-cyclic di-L-glutamate and L-methionine sulfone might be concerned with ammonia assimilation in the pupae, and that D-glucosyl-L-tyrosine served as a switch for the fatty acid (pupal oil) dissimilation hybrid system. 相似文献
997.
Okamoto T Yamada M Sekiya S Okuhara T Taguchi G Inatomi S Shimosaka M 《Bioscience, biotechnology, and biochemistry》2010,74(11):2327-2329
Agrobacterium tumefaciens was used to transform the vegetative dikaryotic mycelium of Flammulina velutipes using a hygromycin B resistance gene as selectable marker. The gene coding for urogen III methyltransferase (cob) was introduced into F. velutipes dikaryotic cells. The resulting transformant cells generated a bright red fluorescence, indicating that cob is promising as a reporter gene in F. velutipes. 相似文献
998.
Hirotoshi Urakawa Keiichi Yamada Keiko Komagoe Setsuko Ando Hiroyuki Oku Takashi Katsu Ichiro Matsuo 《Bioorganic & medicinal chemistry letters》2010,20(5):1771-1775
A series of cationic cyclic heptapeptides based on polymyxin B have been synthesized for use as permeabilizers of the outer membrane of Gram-negative bacteria. Only analogs with the Dab2-d-Phe3-Leu4-Xxx5 sequence (Xxx = Dab or Orn) showed a synergistic bactericidal effect when combined with conventional antibiotics, indicating that the Dab2 residue plays a critical role in permeation of the outer membrane of Gram-negative bacteria. 相似文献
999.
Tomomichi Chonan Hiroaki Tanaka Daisuke Yamamoto Miyoko Yashiro Takahiro Oi Daisuke Wakasugi Ayumi Ohoka-Sugita Fusayo Io Hiroko Koretsune Akira Hiratate 《Bioorganic & medicinal chemistry letters》2010,20(13):3965-3968
Acetyl-CoA carboxylases (ACCs), the rate limiting enzymes in de novo lipid synthesis, play important roles in modulating energy metabolism. The inhibition of ACC has demonstrated promising therapeutic potential for treating obesity and type 2 diabetes mellitus in transgenic mice and preclinical animal models. We describe herein the structure-based design and synthesis of a novel series of disubstituted (4-piperidinyl)-piperazine derivatives as ACC inhibitors. Our structure-based approach led to the discovery of the indole derivatives 13i and 13j, which exhibited potent in vitro ACC inhibitory activity. 相似文献
1000.
Manabu Yamada Mitsuji Yamashita Takuya Suyama Junko Yamashita Kazuhide Asai Taishi Niimi Nobuhisa Ozaki Michio Fujie Kasthuraiah Maddali Satoki Nakamura Kazunori Ohnishi 《Bioorganic & medicinal chemistry letters》2010,20(19):5943-5946
4-Bromo-3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (3c) was first synthesized from 3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (2c) by a bromo-radical substitution reaction occurred at C-4 position by N-bromosuccinimide and 2,2′-azobisisobutyronitrile. The novel phospha sugar analogue 3c exerted high anti-proliferative effect on U937 cells evaluated by MTT in vitro methods and was much more efficient than that of Gleevec®, which is known as a molecule targeting chemotherapeutical agent. The substitution of 2-phospholenes at C-3 and C-4 position with methyl groups as well as 4-bromo substituent suggests a good anti-proliferative effect. 相似文献