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101.
Takahashi T Iwase T Tachibana T Komiyama K Kobayashi K Chen CL Mestecky J Moro I 《Immunogenetics》2000,51(2):85-91
The J chain is a component of polymeric immunoglobulin (Ig) molecules and may play an important role in their polymerization
and the transport of polymeric Ig across epithelial cells. In this study, the primary structure of the chicken J chain was
determined by sequencing cDNA clones. The cDNA had an open reading frame of 476 nucleotides encoding a putative protein of
158 amino acid residues including the signal sequence. The 3′ untranslated region consisted of 1216 nucleotides and a poly(A)
tail. The deduced amino acid sequence of the chicken J chain had a high degree of homology to that of human, cow, rabbit,
mouse, frog, and earthworm, with eight conserved Cys residues identical to the mammalian J chains. Northern blot hybridization
performed with total RNA from various chicken tissues revealed high levels of J-chain mRNA expression in spleen, intestine,
Harderian gland, and bursa of Fabricius, and low levels in the thymus. The J chain was expressed in the bursa as early as
day 15 of embryogenesis. These data indicated that the chicken J-chain gene displays a high degree of homology with that of
other species, and is expressed at an early stage of development of the chicken immune system.
Received: 21 May 1999 / Revised: 30 August 1999 相似文献
102.
103.
Mwamtemi HH Koike K Kinoshita T Ito S Ishida S Nakazawa Y Kurokawa Y Shinozaki K Sakashita K Takeuchi K Shiohara M Kamijo T Yasui Y Ishiguro A Kawano Y Kitano K Miyazaki H Kato T Sakuma S Komiyama A 《Journal of immunology (Baltimore, Md. : 1950)》2001,166(7):4672-4677
We compared a potential to generate mast cells among various sources of CD34(+) peripheral blood (PB) cells in the presence of stem cell factor (SCF) with or without thrombopoietin (TPO), using a serum-deprived liquid culture system. From the time course of relative numbers of tryptase-positive and chymase-positive cells in the cultured cells grown by CD34(+) PB cells of nonasthmatic healthy individuals treated with G-CSF, TPO appears to potentiate the SCF-dependent growth of mast cells without influencing the differentiation into mast cell lineage. CD34(+) PB cells from asthmatic patients in a stable condition generated significantly more mast cells under stimulation with SCF alone or SCF+TPO at 6 wk of culture than did steady-state CD34(+) PB cells of normal controls. Single-cell culture studies showed a substantial difference in the number of SCF-responsive or SCF+TPO-responsive mast cell progenitors in CD34(+) PB cells between the two groups. In the presence of TPO, CD34(+) PB cells from asthmatic children could respond to a suboptimal concentration of SCF to a greater extent, compared with the values obtained by those of normal controls. Six-week cultured mast cells of asthmatic subjects had maturation properties (intracellular histamine content and tryptase/chymase enzymatic activities) similar to those derived from mobilized CD34(+) PB cells of nonasthmatic subjects. An increase in a potential of circulating hemopoietic progenitors to differentiate into mast cell lineage may contribute to the recruitment of mast cells toward sites of asthmatic mucosal inflammation. 相似文献
104.
Cyclopentyl and (+/-)-exo-2-norbornylcarbamates of cellulose and amylose were prepared and their chiral recognition abilities as chiral stationary phases for high-performance liquid chromatography (HPLC) were evaluated. Among these carbamates, cellulose tris(cyclopentylcarbamate) and amylose tris((+/-)-exo-2-norbornylcarbamate) showed particularly high chiral recognition, which is comparable to that of several well-known phenylcarbamate derivatives. The chiral recognition mechanism of cellulose tris(cyclohexylcarbamate), which was previously found to be an effective chiral stationary phase for HPLC, was investigated using NMR spectroscopy. The derivative dissolved in chloroform exhibited the chiral discrimination of several enantiomers in NMR as well as in HPLC. For example, the 1,1'-bi-2-naphthol enantiomers were distinctly discriminated in the (1)H, (13)C, and 2D-NOESY spectra. 相似文献
105.
Izydor Apostol Anthony Giletto Tomoko Komiyama WenLei Zhang Michael Laskowski Jr. 《Journal of Protein Chemistry》1993,12(4):419-433
Ovomucoids consist of a single polypeptide chain which is composed of three tandem Kazal domains. Each Kazal domain is an actual or putative protein inhibitor of serine proteinases. Ovomucoid third domains were already isolated and sequenced from 126 species of birds (Laskowskiet al., 1987, 1990). This paper adds 27 new species. A number of generalizations are made on the basis of sequences from 153 species. The residues that are in contact with the enzyme in enzyme-inhibitor complexes are strikingly hypervariable. While the primary specificity residue,P
1, is the most variable; substitutions occur predominantly among aliphatic, hydrophobic residues. Consensus sequences for an avian ovomucoid third domain, for a b-type Kazal domain (i.e., a COOH terminal domain of multidomain inhibitors) and for a general Kazal domain are given. Finally, the individual new sequences are briefly discussed. 相似文献
106.
107.
108.
Shintaro Sugahara Akihiro Chiyo Koki Fukuoka Yuto Ueda Yuki Tokunaga Youichirou Nishida 《Bioscience, biotechnology, and biochemistry》2013,77(11):1973-1984
ABSTRACTThis study aimed to investigate the unique antioxidative effects of Japanese moringa products, herbal leaf tea and stem tea, using established free radical assays, focusing on superoxide anion (O2?) radical generation systems. Hot-water extracts from moringa teas resulted in different but lower scavenging activities than Trolox in four synthetic free radical models. Interestingly, these extracts further showed higher O2? radical scavenging effects than Trolox in the phenazine methosulfate-NADH-nitroblue tetrazolium and xanthine oxidase assay systems. Incubating human neutrophils in the presence of these tea extracts rather than Trolox effectively suppressed cellular O2? radical generation. Among the eight known phenolic constituents of moringa leaves, caffeic acid and chlorogenic acid may be responsible for the O2–specific radical scavenging capacity stronger than that of Trolox. These results suggest that moringa herbal teas are a good source of natural antioxidants for preventing O2? radical-mediated disorders.Abbreviations: O2?: superoxide anion; ROS: reactive oxygen species; H2O2: hydrogen peroxide; XOD: xanthine oxidase; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ABTS+: 2,2′-azinobis(2-ethylbenzothiazoline-6-sulfonic acid) cation; CPZ+: chlorpromazine cation; PMS: phenazine methosulfate; NBT: nitroblue tetrazolium; PMA: phorbol 12-myristate 13-acetate 相似文献
109.
World Journal of Microbiology and Biotechnology - 相似文献
110.
Mouse genomes show a large cluster of imprinted genes at the Dlk1-Gtl2 domain in the distal region of chromosome 12. An intergenic-differentially methylated region (IG-DMR) located between Dlk1 and Gtl2 is specifically methylated in the male germline; IG-DMR regulates the parental allele-specific expression of imprinted genes. Here, we show the resetting of IG-DMR methylation marks during male germ-cell differentiation. For parental allele-specific methylation analysis, polymorphisms were detected in a 2.6-kb IG-DMR in three mouse strains. Bisulfite methylation analysis showed erasure of the marks by E14 and re-establishment before birth. The IG-DMR methylation status was maintained in spermatogonia and spermatocytes of mature testes. The IG-DMR methylation status established before birth is thus maintained throughout the lifetime in the male germline. 相似文献