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71.
72.
Functional analysis of water channels in barley roots 总被引:1,自引:0,他引:1
73.
Ishihara K Oyaizu S Mizunoya W Fukuchi Y Yasumoto K Fushiki T 《Bioscience, biotechnology, and biochemistry》2002,66(2):426-429
The author modified a respiratory gas analyzer to analyze the respiratory 13CO2 of 12 small laboratory animals all at once. To investigate the practical use of this system, mice were orally (OR) or intravenously (i.v.) given glucose solutions containing three different amounts of 13C-labeled glucose. Expired 13CO2 derived from exogenous glucose was detected within 10 minutes after administration in OR mice, but about 30 minutes in i.v. mice. The height of the peak of 13CO2 expiration was correlated with the administered 13C-glucose mass. 相似文献
74.
Large-scale preparation,purification, and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers 总被引:3,自引:0,他引:3
Hyaluronan (HA) was depolymerized by partial digestion with testicular hyaluronidase and separated into size-uniform HA oligosaccharides from 4-mers to 52-mers by anion exchange chromatography after removal of the hyaluronidase. The purity and size of each HA oligosaccharide was confirmed by using HPLC analyses, FACE, and ESI-MS. (1)H and (13)C NMR assignments and elemental analyses were obtained for each HA oligosaccharide. Endotoxins, proteins, and DNA were absent or in trace amounts in these HA oligosaccharides. Gram/mg-scale hyaluronan oligosaccharides were obtained from 200 g of HA starting material. These pure, size-uniform, and large range of HA oligosaccharides will be available for investigating important biological functions of HA, such as for the determination of the size(s) of HA oligosaccharides that induce angiogenesis or mediate inflammatory responses, and to interact with HA-binding proteins and receptors both in in vitro and in vivo studies. 相似文献
75.
76.
A sex difference in the penetration of selenium into the brain was observed using lipopolysaccharide (LPS)-injected mice.
The selenium concentration increased in the brains of sodium selenite-injected LPS-treated female mice, but not males. The
selenium concentration peaked when selenite was injected 3 h after the injection of LPS into female mice. In addition, selenium
in the brain increased when a dosage of 30 μmol/kg and more of selenite was injected into LPS-treated female mice. Also, the
selenium concentration in the brain increased and peaked 2–3 h after selenite injection; 24 h later, the level was similar
to the Se-only group. The penetration of selenium into the brain was inhibited by pretreatment with aminoguanidine, an inhibitor
of nitric oxide synthetase. From the present results, selenium more easily penetrated into the brains of female mice compared
to males after LPS treatment, and nitric oxide may have affected the penetration. However, the sex difference mechanism for
selenium penetration needs further investigation. 相似文献
77.
The entire amino acid sequence of bifunctional alginate lyase from Pseudoalteromonas sp. strain No. 272 were determined by two approaches, Edman degradation of the peptides obtained from protease digestion of the enzyme protein and analysis of PCR products of the structural gene. The former resulted in incomplete amino acid sequence in the entire sequence, due to lacking of the proper peptides from the protease digestion. To compensate for this lack of sequences we applied the method of PCR of the structural gene that was initially elucidated from the primers designed from N- and C-terminal amino acid sequences of the enzyme. The results of the amino acid sequences from these two approaches showed good agreement. The enzyme consisted of 233 amino acid residues with a molecular mass of 25,549.5, including the sole W and cystine residue. The sequence homology search among the other alginate lyases from different origins indicated that they were very weakly homologous, with the exception of the sequence homology (80.3%) of Pseudoalteromonas elyakovii alginate lyase. The consensus sequence, YFKhG + Y-Q (Wong, T. Y., Preston, L. A., and Schiller, N. L. 2000. Annu. Rev. Microbiol.
54: 289–340) in the C-terminal regions was conserved. The kinetic analyses of chemical modification of some amino acid residues of the enzyme showed that W, K, and Y appeared to be important in the enzyme function. 相似文献
78.
Kagawa Y Yanagisawa Y Hasegawa K Suzuki H Yasuda K Kudo H Abe M Matsuda S Ishikawa Y Tsuchiya N Sato A Umetsu K Kagawa Y 《Biochemical and biophysical research communications》2002,295(2):207-222
The "thrifty" genotype and phenotype that save energy are detrimental to the health of people living in affluent societies. Individual differences in energy metabolism are caused primarily by single nucleotide polymorphisms (SNPs), some of which promote the development of obesity/type 2 diabetes mellitus. In this review, four major questions are addressed: (1) Why did regional differences in energy metabolism develop during evolution? (2) How do genes respond to starvation and affluence? (3) Which SNPs correspond to the hypothetical "thrifty genes"? (4) How can we cope with disease susceptibility caused by the "thrifty" SNPs? We examined mtDNA and genes for energy metabolism in people who live in several parts of Asia and the Pacific islands. We included 14 genes, and the SNP frequencies of PPAR gamma 2, LEPR, and UCP3-p and some other genes differ significantly between Mongoloids and Caucasoids. These differences in SNPs may have been caused by natural selection depending on the types of agriculture practiced in different regions. Interventions to counteract the adverse effects of "thrifty" SNPs have been partially effective. 相似文献
79.
High levels of RAE-1 isoforms on mouse tumor cell lines assessed by anti-"pan" RAE-1 antibody confer tumor susceptibility to NK cells. 总被引:2,自引:0,他引:2
Hisayo Masuda Yoshiko Saeki Midori Nomura Kyoko Shida Misako Matsumoto Michio Ui Lewis L Lanier Tsukasa Seya 《Biochemical and biophysical research communications》2002,290(1):140-145
Two sublines of the benzpyrene-induced mouse hepatoma cell line, G-1 and G-5, showed low and high metastatic ability, respectively, to the lung. We produced a polyclonal antibody (pAb) against RAE-1alpha. Five isoforms of RAE-1 have been identified to date, and this pAb recognized all isoforms and was named anti-"pan" RAE-1 pAb. The level of RAE-1 was approximately 5-fold higher in G-5 than in G-1, which was almost RAE-1-negative, as determined using anti-pan RAE-1 pAb. Expression levels of other markers including MHC class I (MHC-I) and Qa-1b were very low and indistinguishable in these sublines. NK-mediated cytotoxicity was determined with these sublines; G-5 was highly susceptible to NK-mediated cytolysis, while G-1 was relatively resistant. The NK-mediated G-5 > G-1 killing profile was diminished if the G-5 cells were pretreated with F(ab)(2)(') of anti-pan RAE-1 pAb. G-1, when transfected with Rae-1alpha cDNA, acquired NK-responsiveness similar to that of G-5. These and additional data using mouse cell lines with low MHC-I levels and various RAE-1 levels also demonstrated that RAE-1 level is critically associated with NK-susceptibility in tumor cells. 相似文献
80.
Ohyama K Yamano Y Sano T Nakagomi Y Wada M Inagami T 《Biochemical and biophysical research communications》2002,292(2):362-367
To delineate the functional importance of the highly conserved triplet amino acid sequence, Asp-Arg-Tyr (DRY) among G protein-coupled receptors in the second intracellular loop, these residues of rat angiotensin II (Ang II) receptor type 1A (AT(1A)) were changed by alanine or glycine by site-directed mutagenesis. These mutant receptors were stably expressed in CHO-K1 cells, and the binding of Ang II, GTP effect, InsP(3) production, and the acidification of the medium in response to Ang II were determined. The effects of GTPgammaS on Ang II binding in the mutant receptors D125A and D125G were markedly reduced. InsP(3) production of the mutant D125A, D125G, R126A, and R126G was markedly reduced. Extracellular acidification of D125A was not distinguishable from untransfected CHO-K1 cells. Mutant Y127A was able to produce InsP(3) and acidify medium comparable with wild type AT(1A). These results indicate as follows; Asp(125) is essential for intracellular signal transduction involving G protein coupling, Arg(126) is essential for coupling of G(q) protein but not other G proteins, and Tyr(127) is not important for G protein coupling. 相似文献