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排序方式: 共有675条查询结果,搜索用时 15 毫秒
1.
Biochemical Study on the Critical Period for Treatment of the Mottled Brindled Mouse 总被引:2,自引:0,他引:2
Hemizygous mottled brindled mice (Mobr/y mice) were treated by subcutaneous injection of copper and were decapitated on postnatal day 14. Cytochrome c oxidase (COX) activity of the brain mitochondria in the mice given 10 micrograms of copper/g on day 4 or 7 showed significant increases compared with that of untreated Mobr/y animals, and these mice had no neurological symptoms. Mice given 10 micrograms of copper/g on day 12 showed neither increases in COX activity nor clinical improvement. The brain levels of copper, noradrenaline, and dopamine in the mice treated on day 12 were the same as those in animals treated on day 4 or 7. The in vitro activities of dopamine-beta-hydroxylase of the brain were also the same among the treated mice, irrespective of the date of treatment. The results indicate that delays in copper treatment produce irreversible changes in COX activity of the brain and lead to clinical unresponsiveness to treatment. 相似文献
2.
Anne Berit Samuelsen Berit Smestad Paulsen Jens Kristian Wold Svein H. Knutsen Haruki Yamada 《Carbohydrate polymers》1998,35(3-4):145-153
PMIa is a Type II arabinogalactan with anti-complementary activity isolated from the leaves of Plantago major L. It has a molecular weight of 77000–80000 Da and consists of arabinose (38%), galactose (49%), rhamnose (6%), galacturonic acid (7%) and 1.5% protein with hydroxyproline, alanine and serine as the main amino acids. Characterization of PMIa by methylation and GC-MS, methanolysis and GC, Smith degradation, weak acid hydrolysis, 13C-NMR, 1H-NMR, two-dimensional heteronuclear NMR and DEPT show that it consists of 1,3-linked galactan chains with 1,6-linked galactan side chains attached to position 6. The side chains are further branched in position 3 with 1,3-linked galactose residues which have 1,6-linked galactose attached to position 6; these 1,3- and 1,6-linked galactose chains altogether probably form a network. Terminal and 1,5-linked arabinose in furanose form are attached to the galactan mainly through position 3 of the 1,6-linked galactose side chains. 相似文献
3.
H Kobayashi A Inoue T Mikawa H Kuwayama Y Hotta T Masaki S Ebashi 《Journal of biochemistry》1992,112(6):786-791
Two proteins with myosin light chain kinase activity and electrophoretic molecular weights of 155,000 and 130,000 were each isolated from bovine stomach smooth muscle [Kuwayama, H., Suzuki, M., Koga, R., & Ebashi, S. (1988) J. Biochem. 104, 862-866]. The 155 kDa component showed a much higher superprecipitation-inducing activity than the 130 kDa component, when compared on the basis of equivalent myosin light chain kinase activity. In this study, we isolated a cDNA for the entire coding region of the 155 kDa protein. The deduced amino acid sequence revealed a high degree of similarity to those of chicken and rabbit smooth muscle myosin light chain kinases. Multiple motifs, such as three repeats of an immunoglobulin C2-like domain, a fibronectin type III domain, and unusual 20 repeats of 12 amino acids were detected in the sequence. Part of the amino-terminal sequence was similar to that of the actin- and calmodulin-binding domain of smooth muscle caldesmon. These observations suggest that the 155 kDa protein has additional functions other than its enzymatic activity. Two mRNAs of 6.0 and 2.6 kb in length in the bovine stomach smooth muscle RNAs were hybridized with cDNA probes. The 2.6-kb RNA probably encodes telokin, which is the carboxyl terminus of smooth muscle myosin light chain kinase. mRNAs with identical lengths were also detected in bovine aorta. 相似文献
4.
To elucidate the structural basis of the diversity and universality in protein-protein interactions, an exhaustive all-against-all structural comparison of all known protein interfaces in the Protein Data Bank was performed at atomic resolution. After similar interfaces were clustered, approximately 20,000 structural motifs with at least two members were identified, out of which 3678 motifs consisted of at least 10 interfaces. Except for some trivial interfaces involving single α helices, almost all motifs were found to be confined within single protein families. Furthermore, the interaction partners of each motif were found to be very limited, and, accordingly, the interaction networks of the motifs tend to be small and are much more restricted than the binding sites for small ligand molecules. These findings suggest that, at the level of atomic structures, protein-protein interactions are precisely designed; hence, protein interfaces with multiple interacting partners should involve incompletely overlapping multiple interfaces and/or accommodate structural changes upon binding to their targets. 相似文献
5.
6.
In vivo analysis of a new lacZ retrovirus vector suitable for cell lineage marking in avian and other species 总被引:9,自引:0,他引:9
To obtain a replication-defective retrovirus vector well suited for cell lineage marking in early avian embryos, we have constructed and tested a derivative of the avian spleen necrosis virus (SNV) carrying the marker gene lacZ. Consistently high titers of this virus, designated CXL, were produced from retroviral packaging cells with no evidence of contaminating helper virus even after 12 months of continuous culture. CXL expresses lacZ strongly and stably in avian cells and has a host range that extends to other avian and some mammalian species. We show that CXL has the potential to mark a wide variety of chick embryo cell types by infection in ovo. The high titers obtainable with this virus can provide a significant advantage over alternative lacZ vectors, especially in lineage marking of early stage embryos. As an example of this, we show that CXL can be used to mark cells of the precardiac mesoderm in stage 4-5 chick embryos. 相似文献
7.
Takeshi Sassa Katsuhiro Suzuki Emi Haruki 《Bioscience, biotechnology, and biochemistry》2013,77(1):303-304
Quinolactacide isolated from Penicillium citrinum F 1539 was synthesized and evaluated for its insecticidal activities. The key steps of the total synthesis were an acyl migration reaction of the enol ester intermediate and dehydrogenation of tetrahydroquinolactacide with manganese dioxide. The synthesized quinolactacide showed 100% and 42% mortality against the green peach aphid (Myzus persicae) and diamondback moth (Plutella xylostella) at 500 ppm, respectively. 相似文献
8.
9.
Shinichi Nakamura Satoshi Nakashio Masato Mikawa Kiyotaka Yamakawa Seiichi Okumura Shoki Nishida 《Microbiology and immunology》1982,26(1):25-30
A total of 79 Clostridium difficile strains from healthy young and elderly adults, elderly patients without gastrointestinal disease, elderly patients receiving antibiotics without gastrointestinal complications, and elderly patients with antibiotic-associated diarrhea or pseudomembranous colitis were tested for their susceptibilities to 24 antimicrobial agents. All of the 79 strains were inhibited by low concentrations of rifampicin, metronidazole, fusidic acid, vancomycin, ampicillin, and penicillin G. The strains were highly resistant to aminoglycosides, trimethoprim, sulfamethoxazole, nalidixic acid, and cycloserine and often resistant to neomycin, cefoxitin, and cefalexin. Wide variations in the susceptibility of C. difficile strains to erythromycin, clindamycin, lincomycin, chloramphenicol, and tetracycline were found. Strains resistant to erythromycin, clindamycin, and lincomycin were more frequently found among strains isolated from elderly adults than those isolated from young adults, with particularly high frequency among strains isolated from elderly patients receiving antibiotics. None of the 23 strains isolated from healthy young adults was resistant to chloramphenicol. All of the 14 strains resistant to erythromycin, clindamycin, lincomycin, and chloramphenicol were sensitive to tetracycline and all of the 15 strains resistant to erythromycin, clindamycin, lincomycin, and tetracycline were sensitive to chloramphenicol. Only one out of 19 tetracycline-resistant strains was highly toxigenic, whereas 42 (70%) of 60 sensitive strains were highly toxigenic. 相似文献
10.