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排序方式: 共有163条查询结果,搜索用时 15 毫秒
1.
Rapid and high-yield purification of porcine heart tissue-type plasminogen activator by heparin-sepharose choromatography 总被引:2,自引:0,他引:2
A rapid and high-yield procedure for the purification of single polypeptide tissue-type plasminogen activator (t-PA) from porcine heart tissue has been developed. Delipidated heart tissue was extracted with 0.45 M potassium acetate. The extract was fractionated with ammonium sulfate and purified by a combination of affinity chromatography on heparin-Sepharose CL-6B and gel filtration on Toyopearl HW-55S. The final product had a specific activity of 220,000 IU/mg protein and gave a single protein band (apparent molecular weight; 67,000) in SDS-polyacrylamide gels in the presence or absence of a reducing agent. The increase in specific activity was 3,200-fold, most of which was achieved in the step of heparin-Sepharose chromatography. The yield calculated from the active ammonium sulfate precipitate was about 90% and 500 micrograms or more of the purified enzyme was obtained from 1 kg wet tissue. This procedure may also be useful for the large-scale production of highly purified t-PA from other tissues or tissue culture cells. 相似文献
2.
U Okamoto K Sasaki N Nagao I Naiki Y Nagamatsu 《Nihon seirigaku zasshi. Journal of the Physiological Society of Japan》1982,44(11):633-641
Non-plasmin fibrinolysis enzyme was extracted from the lung and spleen of conventional rats (Thrombos. Haemostas., 1979), although the enzyme was not found in germfree rats, suggesting the possibility that the enzyme may participate in the defence mechanism of the body. The present study was made in an attempt to determine the behavior of non-plasmin fibrinolysis enzyme of the lung tissue in the DIC model of conventional rats induced by a single injection of bacterial endotoxin. The plasminogen-activator activity of the lung tissue, and the fibrinogen level, platelet count, urea nitrogen and plasminogen-activator activity in the blood were also measured. Examination of the lung tissue in the DIC rats indicated a remarkable increase in non-plasmin fibrinolysis activity and a disappearance of plasminogen-activator activity. Inhibitor studies using t-AMCHA and DFP demonstrated that the increased non-plasmin fibrinolysis activity was not derived from activated plasmin, but from serine protease. The disappearance of plasminogen-activator activity in the lung and increase of plasminogen-activator activity in the blood suggested a release of the activator from the lung into the blood due to the endotoxin injection. 相似文献
3.
Sphingosine inhibits attachment of murine Lewis lung carcinoma cells to laminin and type IV collagen
The effect of sphingosine (SPH) on the adhesive properties of Lewis lung carcinoma (3LL) cells was investigated using plastic precoated with the extracellular matrix proteins, laminin, fibronectin, or type IV collagen. Treatment of 3LL cells with SPH (0.5-10 microM) resulted in a dose-dependent decrease in the ability to bind to laminin and type IV collagen but had little or no effect on attachment to fibronectin. Phorbol 12-myristate 13-acetate (PMA) selectively enhanced attachment of 3LL cells to laminin and collagen. The inhibitory effect of SPH on attachment to both proteins was competitively antagonized by PMA. These results suggest that SPH acts as a negative effector for cell attachment to laminin and collagen, and that the cell attachment process to both proteins might be regulated in part by protein kinase C. 相似文献
4.
5.
Kazuyuki Nagamatsu 《Journal of biomolecular structure & dynamics》2013,31(4):729-739
Abstract Fluorophore of proflavine was introduced onto the 3′-terminal ribose moiety of yeast tRNAPhe. The distance between the fluorophore and the fluorescent Y base in the anticodon of yeast tRNAPhe was measured by a singlet-singlet energy transfer. Conformational changes of tRNAPhe with binding of tRNAGlu 2, which has the anticodon UUC complementary to the anticodon GAA of tRNAPhe, were investigated. The distance obtained at the ionic strength of 100 mM K+ and 10 mM Mg2+ is very close to the distance from x-ray diffraction, while the distance obtained in the presence of tRNAGlu 2 is significantly smaller. Further, using a fluorescent probe of 4-bromomethl-7-methoxycoumarin introduced onto pseudouridine residue Ψ55 in the TΨC loop of tRNAPhe, Stern-Volmer quenching experiments for the probe with or without added tRNAGlu 2were carried out. The results showed greater access of the probe to the quencher with added tRNAGlu 2. These results suggest that both arms of the L-shaped tRNA structure tend to bend inside with binding of tRNAGlu 2 and some structural collapse occurs at the corner of the L-shaped structure. 相似文献
6.
Elizabeth Dao Jennifer C. Davis Devika Sharma Alison Chan Lindsay S. Nagamatsu Teresa Liu-Ambrose 《PloS one》2013,8(1)
Objectives
To investigate the independent contribution of change in sub-total body fat and lean mass to cognitive performance, specifically the executive processes of selective attention and conflict resolution, in community-dwelling older women.Methods
This secondary analysis included 114 women aged 65 to 75 years old. Participants were randomly allocated to once-weekly resistance training, twice-weekly resistance training, or twice-weekly balance and tone training. The primary outcome measure was the executive processes of selective attention and conflict resolution as assessed by the Stroop Test. Sub-total body fat and lean mass were measured by dual-energy x-ray absorptiometry (DXA) to determine the independent association of change in both sub-total body fat and sub-total body lean mass with Stroop Test performance at trial completion.Results
A multiple linear regression model showed reductions in sub-total body fat mass to be independently associated with better performance on the Stroop Test at trial completion after accounting for baseline Stroop performance, age, baseline global cognitive state, baseline number of comorbidities, baseline depression, and experimental group. The total variance explained was 39.5%; change in sub-total body fat mass explained 3.9% of the variance. Change in sub-total body lean mass was not independently associated with Stroop Test performance (P>0.05).Conclusion
Our findings suggest that reductions in sub-total body fat mass – not sub-total lean mass – is associated with better performance of selective attention and conflict resolution. 相似文献7.
Mimuro H Suzuki T Nagai S Rieder G Suzuki M Nagai T Fujita Y Nagamatsu K Ishijima N Koyasu S Haas R Sasakawa C 《Cell host & microbe》2007,2(4):250-263
Colonization of the gastric pits in the stomach by Helicobacter pylori (Hp) is a major risk factor for gastritis, gastric ulcers, and cancer. Normally, rapid self-renewal of gut epithelia, which occurs by a balance of progenitor proliferation and pit cell apoptosis, serves as a host defense mechanism to limit bacterial colonization. To investigate how Hp overcomes this host defense, we use the Mongolian gerbil model of Hp infection. Apoptotic loss of pit cells induced by a proapoptotic agent is suppressed by Hp. The ability of Hp to suppress apoptosis contributed to pit hyperplasia and persistent bacterial colonization of the stomach. Infection with WT Hp but not with a mutant in the virulence effector cagA increased levels of the prosurvival factor phospho-ERK and antiapoptotic protein MCL1 in the gastric pits. Thus, CagA activates host cell survival and antiapoptotic pathways to overcome self-renewal of the gastric epithelium and help sustain Hp infection. 相似文献
8.
Katahira H Nagamatsu S Ozawa S Nakamichi Y Yamaguchi S Furukawa H Takizawa M Yoshimoto K Itagaki E Ishida H 《Biochemical and biophysical research communications》2001,282(2):507-510
The effects of fatty acids on pancreatic beta cell are still controversial. Here, in order to determine whether free fatty acids acutely affect beta cell functions, we studied the effect of palmitic acid (PA) on proinsulin biosynthesis and insulin secretion using rat islets in vitro. Exposure of islets to PA for 1 h reduced glucose-stimulated proinsulin biosynthesis in a dose-dependent manner; in contrast, no change in insulin secretion was observed after 1 h incubation with PA. Furthermore, PA treatment did not cause any change of preproinsulin mRNA level during 1-h incubation period. Thus, our data indicate that PA primarily suppresses glucose-induced proinsulin biosynthesis within 1 h at the translational level. 相似文献
9.
Nagamatsu S Watanabe T Nakamichi Y Yamamura C Tsuzuki K Matsushima S 《The Journal of biological chemistry》1999,274(12):8053-8060
10.
Watanabe T Nagamatsu S Matsushima S Kirino T Uchimura H 《Biochemical and biophysical research communications》1999,256(3):505-511
Toward elucidating the functional aspects ofGLUT3, a primary neuronal glucose transporter isoform in the vertebrate central nervous system, this study examined its expression in cholinergic amacrine cells made identifiable by the presence of acetylcholine-synthesizing enzyme, choline acetyltransferase (ChAT), in the rat retina. Double-immunofluorescence staining of adult rat retinal tissue with anti-GLUT3 and anti-ChAT antibodies revealed characteristic stratified GLUT3 immunoreactivity (GLUT3-IR) in the inner plexiform layer (IPL) that was identical to the arborization pattern of ChAT-positive neuronal processes there. In addition, approximately 30-50% of intensely GLUT3-immunoreactive cell bodies in the inner nuclear layer and ganglion cell layer showed ChAT-IR, while the majority of ChAT-positive cell bodies were also intensely GLUT3 immunoreactive. Analysis at the cellular level using retinal cells in culture revealed similar findings. These results collectively indicate that cholinergic amacrine cells constitute the major component of GLUT3-expressing cells in the rat retina. It is expected that the link demonstrated here between GLUT3 expression and cholinergic amacrine cell population will provide clues for further analyzing GLUT3 function in the retina. 相似文献