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排序方式: 共有1543条查询结果,搜索用时 109 毫秒
1.
K Ohta M Kitada T Hashizume M Komori H Ohi T Kamataki 《Biochimica et biophysica acta》1989,996(1-2):142-145
Cytochrome P-450, designated as P-450-MK2, was purified to an electrophoretic homogeneity from polychlorinated biphenyl (PCB)-treated female crab-eating monkeys. P-450-MK2 catalyzed nifedipine and nilvadipine oxidations, at a rate comparable to human P-450-HM1. The N-terminal amino acid sequence of P-450-MK2 was highly homologous to those of P-450-HM1 and NF 25. The antibodies to P-450-HM1 recognized P-450-MK2 and effectively inhibited the activity of testosterone 6 beta-hydroxylase in monkey liver microsomes. These results suggest that a form of cytochrome P-450 corresponding to human P-450-HM1 or P-450NF which belongs to the P450 III gene family is also present in liver microsomes of crab-eating monkeys. 相似文献
2.
Isolation and Characterization of an Enterobacter cloacae Strain That Reduces Hexavalent Chromium under Anaerobic Conditions 总被引:12,自引:6,他引:6 下载免费PDF全文
Pi-Chao Wang Tsukasa Mori Kohya Komori Masanori Sasatsu Kiyoshi Toda Hisao Ohtake 《Applied microbiology》1989,55(7):1665-1669
An Enterobacter cloacae strain (HO1) capable of reducing hexavalent chromium (chromate) was isolated from activated sludge. This bacterium was resistant to chromate under both aerobic and anaerobic conditions. Only the anaerobic culture of the E. cloacae isolate showed chromate reduction. In the anaerobic culture, yellow turned white with chromate and the turbidity increased as the reduction proceeded, suggesting that insoluble chromium hydroxide was formed. E. cloacae is likely to utilize toxic chromate as an electron acceptor anaerobically because (i) the anaerobic growth of E. cloacae HO1 accompanied the decrease of toxic chromate in culture medium, (ii) the chromate-reducing activity was rapidly inhibited by oxygen, and (iii) the reduction occurred more rapidly in glycerol- or acetate-grown cells than in glucose-grown cells. The chromate reduction in E. cloacae HO1 was observed at pH 6.0 to 8.5 (optimum pH, 7.0) and at 10 to 40°C (optimum, 30°C). 相似文献
3.
4.
Toshio Shimada Dr. Yoshimasa Kosako Yasunori Isshiki Kazuhito Hisatsune 《Current microbiology》1992,25(4):215-217
The O antigen of enterohemorrhagicEscherichia coli O157:H7 is identical with that ofSalmonella O301 and is also related toSalmonella O301302 in an a-a, b type of relationship. 相似文献
5.
Naoki Yamashita Isao Nakanishi Yasunori Okada 《Virchows Archiv. B, Cell pathology including molecular pathology》1991,60(1):57-66
Arthritis was induced by injecting cationic amidated bovine serum albumin (aBSA) (pI approximately 9.2) into the knee joint of immunized guinea pigs and the mechanisms of articular cartilage destruction were studied morphologically and biochemically. Marked synovitis associated with polymorphonuclear leukocyte (PML) infiltration occurred within 1 day of the challenge. Articular cartilage infiltrated by PMLs was almost completely destroyed after 2 weeks. During the initial destructive process, proteoglycans were depleted from the cartilage and later collagen fibers disappeared. Granulation tissue growing in the inflamed synovium and bone marrow replaced the destroyed cartilage and joint cavity and formed fibrous scar tissue (fibrous ankylosis) by 8 weeks. Subsequently, the knee joints developed cartilagenous ankylosis by 12 weeks and finally bony ankylosis at 28 weeks. Autoradiography using 125I-aBSA and immunofluorescence studies for immunoglobulin (IgG) and complement (C3) demonstrated that the antigen is trapped in all zones of the articular cartilage and serves as a trigger for immune complex formation. Significantly increased neutral proteinase activities against substrates of proteoglycan subunits, [3H]carboxymethylated transferrin and L-pyroglutamyl-L-prolyl-L-valine-paranitroanilide were detected in homogenates of the synovium and cartilage from arthritic knee joints 1 and 2 weeks after induction. Inhibitor studies and pH curves suggested that the proteinase is leukocyte elastase. Measurable amounts of gelatinolytic activity, detected by activation with 4-aminophenylmercuric acetate and inhibited with EDTA, were also present in the same samples, but there was no detectable collagenase activity. The data on SDS-gelatin substrate gel showed that the proteinase is gelatinase derived from PMLs. These results suggest that in aBSA-induced arthritis, elastase and gelatinase from PMLs invading articular cartilage may play important roles in cartilage destruction. 相似文献
6.
1. A hemorrhagic factor was isolated from Vipera a. aspis venom by gel filtration, ion-exchange chromatography and affinity chromatography. 2. Molecular weight of the purified factor was determined to be 67,000 Da, which was composed of 552 amino acid residues. 3. The minimum hemorrhagic dose (MHD) was measured to be 0.11 micrograms per mouse with subcutaneous injection. The hemorrhagic activity was inhibited by chelating agents and reductant. 4. The hemorrhagic factor possesses proteolytic activity against dimethylcasein. 5. Serum creatine phosphokinase level was rapidly increased within 30 min following injections of this preparation into the mice thighs. 6. Actin, one of the main components of muscle fiber, is apparently digested by the hemorrhagic factor. The pathological findings are further reported in this paper. 相似文献
7.
Hemorrhagic proteinase, HTb, isolated from Crotalus atrox (western diamondback rattlesnake) venom was studied for its specificity. HTb showed fibrinogenase activity, hydrolyzing the A alpha chain of fibrinogen first, followed by the cleavage of the B beta chain. HTb is different from thrombin and did not produce a fibrin clot. The degradation products of fibrinogen were found to be different, indicating that the cleavage sites in the A alpha and B beta chains are different from those of thrombin. N-Benzoyl-Phe-Val-Arg-p-nitroanilide was not hydrolyzed by HTb, although this substrate was hydrolyzed by thrombin and reptilase. 相似文献
8.
In Dunaliella tertiolecta, D. bioculata and D. viridis the activitiesof phosphoenolpyruvate carboxylase and carbonic anhydrase werehigher in the cells grown in ordinary air (low-CO2 cells) thanin those grown in air enriched with 15% CO2 (high-CO2cells), whereas in Porphyridium cruentum R-1 there was no differencein phosphoenolpyruvate carboxylase activity between these twotypes of cells. Apparent Km(NaHCO3) values for photosynthesisin low-CO2 cells of all species tested were smaller than thosein high-CO2 cells. Most of the 14C was incorporated into 3-phosphoglycerate,sugar mono- and di-phosphates during the initial periods ofphotosynthetic NaH14CO3 indicating that both types of cellsin D. tertiolecta are C3 plants. (Received May 27, 1985; Accepted June 25, 1985) 相似文献
9.
Masahiro Miyazaki Yasunori Suzuki Munehiro Oda Akira Kawai Liyan Bai Jiro Sato 《In vitro cellular & developmental biology. Plant》1989,25(9):839-848
Summary For serum-free primary culture of adult rat hepatocytes, a synthetic medium DM-160 and rat-tail collagen were selected for
the basal medium and for the culture substratum, respectively. Barbiturates, such as phenobarbital and 1-ethyl-5-isobutylbarbiturate,
efficiently supported survival of hepatocytes and maintained their morphologic features at lower concentrations under the
serum-free conditions than under the serum-supplemented conditions. However, the hepatocyte survival rates under the serum-free
conditions were lower than those under the serum-supplemented conditions in the presence or absence of barbiturates. Supplementation
of the basal medium with a combination of five groups of factors (5Fs), such as eight amino acids (Ala, Arg, Gly, Ile, Met,
Phe, Pro, and Trp), two unsaturated fatty acids (linoleate and oleate), a protease inhibitor (aprotinin), three vitamins (A,
C, and E), and five trace elements (Mn, Fe, Cu, Zn, and Se), improved the hepatocyte survival under the serum-free conditions
in the presence or absence of barbiturates. In other words, the serum could be completely substituted by the 5Fs. Hepatocyte
cultures maintained in the 5Fs-suppelemented basal medium showed excellent induction of tyrosine aminotransferase activity
in response to dexamethasone in the presence or absence of barbiturates. The efficiency of the 5Fs-supplemented basal medium
for maintaining hepatocytes was not inferior to those of other media in common use with hepatocytes, such as Williams' medium
E and Waymouth's medium MB-752/1. In conclusion, maintenance of functional hepatocytes in serum-free primary culture could
be improved by use of the new medium preparation (the 5Fs-supplemented DM-160) in the presence of barbiturates.
This work was supported by a grant no. 61771923 from the Ministry of Education, Science and Culture of Japan. 相似文献
10.
Molecular cloning and sequence analysis of cDNA containing the entire coding region for human fetal liver cytochrome P-450 总被引:4,自引:0,他引:4
From a human fetal liver cDNA library, a cDNA clone (lambda HFL33) containing the entire coding region for a form of cytochrome P-450 related to P-450 HFLa was obtained. The clone was 1,971 bp long and had an open reading frame of 1,509 nucleotides coding for a 503 amino acid polypeptide. The nucleotide and the deduced amino acid sequences of lambda HFL33 were very similar to but clearly distinct from those of NF25 and HLp cDNAs, which code for forms of cytochrome P-450 in adult human liver. The deduced N-terminal amino acid sequence of the HFL33 protein was identical to that of P-450 HFLa. 相似文献