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1.
Masanori Shinzato Mikihiro Shamoto Satoru Hosokawa Chiyuki Kaneko Akido Osada Miyuki Shimizu Asako Yoshida 《Biotechnic & histochemistry》1995,70(3):114-118
The present study shows that Langerhans cells can be differentiated from Interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells. 相似文献
2.
Matrix Gla protein (MGP) regulates calcification in cartilage and arteries. MGP synthesis during embryonic development and its binding and regulation of growth factors and morphogens of the TGF-beta/BMP superfamily suggests that it has additional functions. Assay by far-western gel overlays and gel filtration shift shows MGP binds vitronectin. Binding is saturable and consistent with a single class of binding sites. MGP binds to vitronectin but not collagen, fibromodulin, heparin, osteocalcin, chondroitin sulfate, laminin, ovalbumin or albumin. We have identified a vitronectin binding site within a 17-amino acid peptide 61-77 near the carboxyl-terminus that corresponds to a naturally occurring MGP C-terminus. MGP and the 61-77 MGP peptide also binds to fibronectin. MGP and vitronectin are focally co-localized in embryonic tissues. Co-localization in vivo suggests that the MGP and vitronectin interactions may modify cell-matrix interactions. Alternatively, vitronectin-bound MGP may have altered function for modulating BMP2 or TGF-beta activity. The current study demonstrates that MGP has a novel binding activity for vitronectin, an extracellular protein that promotes cell-matrix interactions and regulates coagulation. 相似文献
3.
Metabolism of 32-hydroxy-24,25-dihydrolanosterol (lanost-8-ene-3 beta,32-diol), a posturated intermediate of the 14 alpha-demethylation (removal of C-32) of 24,25-dihydrolanosterol (lanost-8-en-3 beta-ol), by a reconstituted system consisting of yeast cytochrome P-450 which catalyzes lanosterol 14 alpha-demethylation (cytochrome P-45014DM) (Yoshida, Y., and Aoyama, Y. (1984) J. Biol. Chem. 259, 1655-1660 and Aoyama, Y., Yoshida, Y., and Sato, R. (1984) J. Biol. Chem. 259, 1661-1666) and NADPH-cytochrome P-450 reductase was studied. The reconstituted system converted both 32-hydroxy-24,25-dihydrolanosterol and 24,25-dihydrolanosterol to 4,4-dimethyl-5 alpha-cholesta-8,14-dien-3 beta-ol, the 14 alpha-demethylated product of the latter. The metabolism of these compounds was inhibited by a low concentration of ketoconazole which is a potent cytochrome P-45014DM inhibitor. Affinity of cytochrome P-45014DM for 32-hydroxy-24,25-dihydrolanosterol was about 20 times higher than for 24,25-dihydrolanosterol and the cytochrome metabolized the former about 4 times faster than the latter under the experimental conditions. Spectral analysis suggested that the 32-hydroxyl group of 32-hydroxy-24,25-dihydrolanosterol interacted with the heme iron of the oxidized cytochrome and this interaction might support the high affinity of this compound for the cytochrome. These lines of evidence indicate that 32-hydroxy-24,25-dihydrolanosterol is the intermediate of the 14 alpha-demethylation of 24,25-dihydrolanosterol by cytochrome P-45014DM. It is also clear that the cytochrome catalyzes further metabolism of the 32-hydroxylated intermediate to the 14 alpha-demethylated product with higher efficiency than the 32-hydroxylation of the substrate. Cytochrome P-45014DM is thus classified as lanosterol C14-C32 lyase. 相似文献
4.
A small cryptic plasmid, pLJ1, was isolated from Lactobacillus helveticus subsp. jugurti and was cloned into Escherichia coli HB101 by using pBR329 as a vector. Plasmid pLJ1 was 3,292 base pairs long and had single restriction endonuclease sites for PvuII, KpnI, AvaII, Acci, HindIII, and EcoRI. In a maxicell system, pLJ1 produced a protein of about 41 kilodaltons. 相似文献
5.
T Aoyama K Korzekwa K Nagata J Gillette H V Gelboin F J Gonzales 《European journal of biochemistry》1989,181(2):331-336
The modified vaccinia virus, T7-RNA-polymerase cDNA-expression system was used to express rat cytochrome P-450a. Various parameters such as host-cell type and density, and duration of infection were tested to optimize the level of expression of cytochrome P-450a enzyme activity. Cytochrome P-450a expressed from the cDNA sequence was exclusively incorporated into the membrane-containing portions of the cell lysates, as expected from its normal association in the liver endoplasmic reticulum. The enzyme displayed a carbon-monoxide-reduced-cytochrome-P-450a difference spectrum with a Soret maximum of 450 nm. Activity measurements revealed that cytochrome P-450a produced three metabolites of testosterone; 7 alpha-hydroxytestosterone and 6 alpha-hydroxytestosterone and delta 6-testosterone at a ratio of about 38:1:1. Under the appropriate conditions, the vaccinia-virus, T7-RNA-polymerase system produces high levels of a single form of cytochrome P-450 in cells that are virtually devoid of endogenous cytochrome P-450. Analysis of the cytochrome P-450 in its natural membrane-bound state, as opposed to artificial-lipid reconstitution studies of purified enzymes, allows accurate and confident measurements of substrate specificities. 相似文献
6.
The primary structure of rat ribosomal protein L18a 总被引:3,自引:0,他引:3
The amino acid sequence of rat ribosomal protein L18a was deduced from the sequence of nucleotides in a recombinant cDNA. Ribosomal protein L18a contains 175 amino acids and has a molecular mass of 20,047 Da. Hybridization of the cDNA to digests of rat nuclear DNA and to a preparation of poly(A)+ mRNA suggests that there are 8-11 copies of the L18a gene and that the mRNA for the protein is about 700 nucleotides in length. Rat L18a is related to Schizosaccharomyces pombe L17 and perhaps to Halobacterium marismortui L19. 相似文献
7.
Satoru Furukawa Akio Ozaki Yukinobu Kotani Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(2-3):253-257
Summary
l-Threonine hyper-producing mutants were obtained fromEscherichia coli W strain KY-8366, by reducingl-threonine degradation activity and enhancingl-threonine biosynthetic activity. Anl-threonine degradation reaction test using resting cells of KY-8366 suggested that the main pathway ofl-threonine degradation by KY-8366 is via glycine. A strain with reducedl-threonine degradation activity was obtained among those mutants that could not utilizel-threonine as sole nitrogen source. Rifampicin-resistant mutants andl-lysine plus methionine-insentitive mutants were isolated. These mutants showed enhanced aspartokinase levels and accumulated morel-threonine than the parental strains. Mutant H-4290 accumulated 58 g/l ofl-threonine. 相似文献
8.
Satoru Furukawa Akio Ozaki Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(6):550-553
Summary Growth and l-threonine productivity of l-threonine producer Escherichia coli H-4290 were inhibited by precursor amino acids, l-homoserine and l-aspartate. l-Threonine hyper-producers were isolated among the mutants resistant to l-homoserine and l-aspartate. Mutants H-4351 (Homr) and H-4578 (Homr, Aspr) accumulated 22.2 g/l and 24.3 g/l of l-threonine in test tube cultures, while the parental strain H-4290 accumulated 18.2 g/l. The enzyme level of aspartokinase I (first enzyme of the threonine operon) was enhanced 2.3 times (H-4351) and 3 times (H-4578) that of H-4290. Mutant H-4578 accumulated 76 g/l of l-threonine in a 2-l jar fermentor after 75 h cultivation.Abbreviations DAP
diaminopimeric acid
- Met
l
poor growth in methionine-free medium
- AHV
-amino--hydroxyvaleric acid
- Thr-N-
lack of ability to utilize l-threonine as a nitrogen source
- Rif
rifampicin
- Lys+Metr
resistant to l-lysine and dl-methionine 相似文献
9.
10.
Striking homology of the ''variable'' N-terminal as well as the ''conserved core'' domains of the mouse and human TATA-factors (TFIID). 总被引:18,自引:9,他引:9
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T Tamura K Sumita I Fujino A Aoyama M Horikoshi A Hoffmann R G Roeder M Muramatsu K Mikoshiba 《Nucleic acids research》1991,19(14):3861-3865