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1.
用国产微孔玻璃珠从CD-1工程细胞株培养上清中纯化u-PA,摸索了微孔玻璃珠结合u-PA的条件和洗脱方法,比较了硫酸铵线性梯度洗脱或25%乙二醇洗脱u-PA活性的结果,最后确定洗脱的条件为0.25mol/LTris、1~2mol/L(NH4)2SO4、pH9.3。经此一步纯化,u-PA比活性达到15329IU/mg,回收率78%,还原条件下SDS-PAGE分子量为52×103的单链u-PA占74%。  相似文献   

2.
中麻黄悬浮培养体系的建立   总被引:5,自引:1,他引:4  
本文用中麻黄无菌苗为外植体,其切段培养在附加2mg/L2,4-D和0.5mg/L 6 BA的MS培养基上,全部脱分化形成白色疏松愈伤组织。愈伤组织继代培养于MS+0.5mg/L2,4-D+0.2mg/L6BA+0.2mg/L NAA+4%蔗糖的培养某上。以继代培养愈伤组织为材料进行悬浮培养,培养基为附加0.2mg/L2,4-D+0.1mg/L6BA+0.1mg/LNAA+2%蔗糖的MS液体培养基,得到分散性好,细胞形状接近圆形,细胞大小均一,细胞团多由2-30个细胞组成的悬浮培养体系。第三代悬浮培养细胞增长率为0.35g·fw/20ml·d,细胞有丝分裂指数为11.2%。条件培养和高密度接种可缩短延迟期,条件培养不能提高分裂指数,1g/10ml接种密度可使分裂指数提高至21.2%。  相似文献   

3.
巨大芽孢杆菌产胞外青霉素酰化酶发酵液经硫酸铵分级抽提及SephadexG-100、羟基磷灰石、DEAE纤维素DE52等层析步骤,提纯了青霉素酰化酶,得到电泳均一的酶制剂。纯酶比活力约为25U/mg蛋白,纯化49倍,活力回收58%,经PAGE及SDS-PAGE测知该酶不含亚基,其分子量约为140kD。该酶最适pH为9.0,最适温度47℃,用底物NIPAB测活,其Km值为6.2×10~(-4)mol/L,Vm值为1.24×104mol/L。此外还探讨了部分金属离子对该酶的影响。  相似文献   

4.
胞外青霉素酰化酶的纯化及部分理化性质   总被引:1,自引:0,他引:1  
巨大芽孢杆菌产胞外青霉素酰化酶发酵液经硫酸铵分级抽提及Sephadex G-100、羟基磷灰石、DEAE-纤维素DE52等层析步,提纯了青霉素酰化酶,得到电泳均一的酶制剂,纯酶比活力约为25U/mg蛋白,纯化49倍,活力回收58%,经PAGE及SDS-PAGE测知该酶不含亚基,其分子量约为140kD。该酶最适pH为9.0,最适温度47℃,用底物NIPAB测活,其Km值为6.2×10^-4mol/L  相似文献   

5.
用硫酸铵分级沉淀、DEAE-纤维素离子交换层析、免疫亲和层析、SephadexG100凝胶柱层析从人胃组织中提取出腺苷脱氨酶,酶纯化19324倍,比活力为5797U/mg蛋白.提取酶液经PAGE、SDS-PAGE和等电聚焦只呈现一条区带。测得该酶的分子量为41.2kD,等电点为pH4.8.氨基酸组成分析表明该酶由388个氨基酸残基组成,N端氨基酸为精氨酸。酶的最适pH为6.5,pH小于5.0或大于9.0时不稳定;最适温度为37℃,对热不太稳定,以腺苷及2-脱氧腺苷作为底物,其Km分别为87μmol/L和41μmol/L。  相似文献   

6.
运用行为测痛结合蓝斑(LC)灌流液去甲肾上腺素(NE)的高压液相(HPLC)测定;观察 大鼠痛阈(PT)与LC灌流液中去甲肾上腺素含量变化间的相互关系,结果表明:(l)视上核 (SON)内注射 10μmL-谷氨酸(L-glutamicacid, L-Glu)后 30分钟,大鼠PT较注射前增加133. 2± 21.4%,此时LC 灌流液中NE含量从注射前的437.3±20.4ng/ml降到229.2±11.9ng/ml,注射 后60分钟PT仍比注射前高83.9±14.7%,而灌流液中NE的含量为328.6±28.0ng/ml,与人工 脑脊液(ACSF)对照组相比有非常明显的差别(P<0.05~0.001)。(2) SON注射L-Glu后,电 针足三里30分钟(L-GIU+EA组)增加到注射前的188.2±23.9%,同ACSF电针组(ACSF+ EA)的 94.9±7.1%相比有明显差异(P<0.01)。此时LC灌流液中NE的含量虽较注射前都明显 降低、分别为137.6±7.5ng/ml和 151,1±11.5ng/ml,但两者相比无明显差异。停针后30分钟L- Glu+EA组的PT仍比注射前高133.8±27.9%,明显高于  相似文献   

7.
螺旋藻对小鼠SOD和GSH—Px活力的影响   总被引:1,自引:0,他引:1  
李春坚 《蛇志》1997,9(3):66-67
采用微量测定法,观察螺旋藻对32只昆明种小白鼠全血中超氧化物歧化酶(SOD)和谷光甘肽过氧化物酶(GSH-Px)活性的影响。结果表明,灌胃螺旋藻试验组(SOD)活性(1577.16±169.88IU/gHb),与相应对照组(1336.27±158.23IU/gHb)比较,GSH-Px活性(28.33±2.37IU/ml)与相应对照组(24.87±3.26IU/ml)比较,差别均有非常显著意义(P<0.01);提示螺旋藻有提高动物SOD和GSH-Px活性的功效  相似文献   

8.
藏红花愈伤组织诱导及其细胞培养的研究   总被引:4,自引:0,他引:4  
藏红花幼叶愈伤组织的诱导频率在MS,B5和White三种培养基上均高达98%;幼叶和芽的诱导率差异不大,高达99%;不同时期的叶片差异较大,以幼叶诱导为佳;球茎诱导率为近80%;激素配比以2.4-D2.0mg/L,BAP0.1~0.5ml/L为宜。在继代培养阶段,MS比B5和White更适合细胞的快速生长繁殖;并且以叶片的愈伤组织生长较快,芽次之,球茎最慢,适合于细胞生长的激素配比为NAA2.0~3.0mg/L,BAP0.5~1.0mg/L为宜。  相似文献   

9.
以对硝基苯糖苷基为底物,测定了慈菇的12种糖苷酶,其中α-甘露糖苷酶、α-和β-半乳糖苷酶活力较高;经硫酸铵分级沉淀,SephadexG-150分子筛层析,ConASepharose4B亲和层析,DEAE-SepharoseCL-6B离子交换层析,从慈菇抽提液纯化了α-半乳糖苷酶。纯化酶的比活提高1072倍,活力回收15.6%,在圆盘聚丙烯酰胺凝胶电泳和SDS-PAGE上均显示1条蛋白质带,在α-半乳糖苷酶浓度为150mU/ml的溶液中测不到其他糖苷酶的活力。慈菇α-半乳糖苷酶的分子量用SephadexG-100凝胶过滤柱测定或在SDS-PAGE上测定均为60kD,酶反应的最适pH在5.8附近,最适温度为60℃。该酶分解对硝基苯基-α-半乳糖苷的K_m值为3.7×10 ̄(-4)mol/L,V_m值为2.1×10 ̄(-4)mol/L。银离子、汞离子显著抑制酶活力,D-半乳糖和密二糖均竞争性地抑制该酶水解对硝基苯基α-D-半乳糖苷的活力,根据Dixon作图求得其K_i值分别为0.92×10 ̄(-3)mol/L和1.98×10 ̄(-3)mol/L。2-脱氧-D-半乳糖和L-岩藻糖为酶活力的非竞争性抑制剂。化学修饰  相似文献   

10.
水杨酸对黄瓜叶片抗氧化剂酶系的调节作用   总被引:27,自引:0,他引:27  
分析了水杨酸(SA)对黄瓜(CucumissativusL.)叶片抗氧化剂酶系活性及活性氧水平的调节作用。不同浓度的SA(0.5mmol/L、1mmol/L、2.5mmol/L、5mmol/L)均能显著地提高被处理叶片超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,而且还能诱导同株的非处理叶片中SOD和POD活性增加。用1mmol/LSA处理第一片真叶,在处理后6~72h,POD活性增加了22%~67%,同株非处理的第二片真叶POD活性增加了14%~86%,但是,在SA处理后3h之前以及处理96h之后,POD活性没有变化。SA能够显著降低超氧物阴离子含量和提高过氧化氢水平,但它对过氧化氢酶(CAT)活性的抑制作用很弱,表明SA提高体内过氧化氢含量的原因主要是通过提高SOD活性而不是抑制CAT活性。同工酶分析表明,SA不能诱导新的SOD同工酶,但可以诱导新的POD同工酶。  相似文献   

11.
白介素—2对心肌细胞[Ca^2+]i的作用及其信号转导途径   总被引:9,自引:1,他引:8  
Cao CM  Xia Q  Ye ZG  Zhang X 《生理学报》2001,53(6):425-430
为研究白介素-2(interleukin-2,IL-2)对心肌细胞内钙浓度([Ca^2 ]i)的影响及其信号转导途径,实验采用酶解法分离成年大鼠心室肌细胞,以Fura-2/AM为钙探针,用细胞内双波长钙荧光系统检测细胞[Ca^2 ]i的变化。结果发现:(1)IL-2(0.5-200U/ml)浓度依赖性地降低单个心室肌细胞内钙态,IL-2(200U/ml)对咖啡因诱导的肌浆网内储钙的释放无影响;(2)纳洛酮(naloxone,Nal)(10^-8mol/L)和nor-binaltorphimine(nor-BNI,10^-8mol/L)可阻断IL-2对心肌细胞钙瞬态的作用,而纳曲吲哚(naltrindole,NTI)(10^-6mol/L)不能阻断此作用;(3)κ阿片受体激动剂U50488H(10^-6mol/L)降低心肌细胞钙瞬态,nor-BNI(10^-8mol/L)可阻断此作用;(4)5mg/L百日咳毒素(PTX)预处理可取消IL-2降低心肌细胞钙瞬态的作用,而酪氨酸激酶抑制剂genistein(10^-4mol/L)不能取消IL-2的作用;(5)U73122预处理可阻断IL-2的作用。研究结果表明,IL-2降低心肌细胞钙瞬态的作用,是通过心肌细胞上κ阿片受体介导的,其下游途径包括PTX敏感的G蛋白和磷脂酶C。  相似文献   

12.
Interleukin-1 beta (IL-1 beta), one of the polypeptide lymphokines released in response to antigen, toxins, injury or inflammation by nearly all cell types, has multiple systemic effects. In the present study the effect of IL-1 beta on follicle stimulating hormone (FSH)-induced estrogen production in primary culture was investigated. Granulosa cells obtained from immature estrogen-treated female rats were cultured for 3 days with increasing doses of FSH (1-30 ng/ml) with or without increasing doses of IL-1 beta (2-20 U/ml). The FSH stimulated estrogen production is dose-dependent, whereas IL-1 beta alone did not affect estrogen biosynthesis. In contrast, simultaneous treatment with IL-1 beta caused a dose-dependent inhibition of FSH action. This inhibitory effect of IL-1 beta was evident 48 h after the treatment. Furthermore, IL-1 beta inhibited forskolin (10(-5) mmol/L) and (Bu)2 cAMP (10(-2) mmol/L)-stimulated estrogen production, indicating a post-cyclic AMP site of action. The present study suggests that IL-1 beta is a potent modulator of granulosa cell steroidogenesis. Decreased estrogen formation may contribute to the follicle atresia and the impaired reproductive functions during injury and inflammation.  相似文献   

13.
The essential oils isolated from nine geographical provenances of indigenous cinnamon (Cinnamomum osmophloeum Kaneh.) leaves were examined by GC-MS and their chemical constituents were compared. According to GC-MS and cluster analyses the leaf essential oils of the nine provenances and their relative contents were classified into six chemotypes-cinnamaldehyde type, cinnamaldehyde/cinnamyl acetate type, cinnamyl acetate type, linalool type, camphor type and mixed type. In addition, the antifungal activities of leaf essential oils and their constituents from six chemotypes of indigenous cinnamon were investigated in this study. Results from the antifungal tests demonstrated that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type had an excellent inhibitory effect against white-rot fungi, Trametes versicolor and Lenzites betulina and brown-rot fungus Laetiporus sulphureus. The antifungal indices of leaf essential oils from these two chemotypes at the level of 200 micro/ml against T. versicolor, L. betulina and L. sulphureus were all 100%. Among them, the IC(50) (50% of inhibitory concentrations) value of the essential oil of cinnamaldehyde type leaf against L. sulphureus was 52-59microg/ml. Cinnamaldehyde possessed the strongest antifungal activities in comparison with other constituents of the essential oils from cinnamaldehyde type leaf, at the level of 100microg/ml its antifungal indices against T. versicolor, L. betulina and L. sulphureus were 100%. The IC50 values of cinnamaldehyde against T. versicolor, L. betulina and L. sulphureus were 73, 74 and 73microg/ml, respectively.  相似文献   

14.
将编码人 94个氨基酸的前列腺分泌蛋白 ( PSP94) c DNA与酵母整合载体 p PICZαA重组 ,构建的重组质粒线性化后转染酵母细胞 GS1 1 5,获得了 PSP94在酵母细胞中遗传性稳定表达酵母工程细胞 .诱导后的培养物中 ,rh PSP94表达量约为 0 .9mg/L,分子量约 1 6.5k D.培养上清经离子交换层析纯化后 ,目的蛋白的纯度为 92 % .体外在人前列腺癌细胞上活性分析表明 ,rh PSP94以1 0 0μg/L ,对该细胞的抑制率 2 0 .4% ;单纯新型 TNF,以 1 0 3 U/ml,抑制率 2 9.8% ;rh PSP94和新型 TNF以上述同样剂量联合应用 ,抑制率为 86.3% .提示 PSP94在体外对抗前列腺癌细胞有杀伤作用 ,但不明显 ;PSP94与新型 TNF联合应用 ,可使抑制率明显提高 ,可能 PSP94与新型 TNF有协同抗前列腺癌的作用 .  相似文献   

15.
Adult T cell leukemia-derived factor (ADF) is a human homologue of thioredoxin with many biologic functions including IL-2R induction, growth promotion, thiol-dependent reducing activity, and radical scavenging activity. The regulatory effect of ADF on the cytotoxic activity of TNF was examined by using a human histiocytic lymphoma cell line, U937. When U937 cells were preincubated with recombinant ADF (rADF) (0.1-100 micrograms/ml) at 37 degrees C for 30 min, TNF-dependent cytotoxicity on U937 cells was markedly inhibited. This inhibitory effect was as high as 95% in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (rADF 100 micrograms/ml) and 85% in the 51Cr-releasing assay (rADF 10 micrograms/ml). After pretreatment of U937 cells with IFN-gamma to augment the sensitivity to TNF, an inhibitory effect of rADF was also found. When U937 cells were washed after preincubation with rADF, resistance to TNF-dependent cytotoxicity was still observed, indicating that rADF inhibited the sensitivity of U937 to TNF-dependent cytotoxicity rather than modifying TNF molecules. Scatchard analysis of TNF receptors on U937 cells using 125I-TNF showed that rADF modulated neither the density nor the affinity of the cell membrane significantly. rADF also reduced the cytotoxicity induced by anti-Fas IgM mAb which shows cytotoxicity quite similar to TNF. rADF (10 micrograms/ml) reduced 90% of the cytotoxicity by anti-Fas IgM mAb, without a detectable change either in Fas Ag expression (MFI 58.1 vs 53.3) or in the degradation of anti-Fas IgM mAb as determined by flow cytometric analysis. These findings indicated that the rADF-induced resistance to the cytotoxic effect of TNF and anti-Fas mAb was not related to the modulation of the TNF receptor or Fas Ag.  相似文献   

16.
This study investigates the effect of intraperitoneal injection of L. bulgaricus and S. thermophilus on interferon production by Swiss mice. The serum from mice given 5 x 10(7) L. bulgaricus in 0.5 ml saline showed a maximal production of 300 U/ml of alpha/beta interferon activity six hours after injection. Cellular integrity appears to be necessary for stimulation; heat-treated bacteria had little effect, while irradiated-bacteria had a greater effect. TNF was also produced, the sera of mice with high IFN also contained 300 U/ml TNF. Streptococcus thermophilus produced no detectable increase in serum IFN, but the 2'-5' A synthetase activity of peritoneal cells was elevated suggesting that small amounts of interferon were produced. Injection of Streptococcus thermophilus plus Lactobacillus bulgaricus did not change the serum interferon response to L. bulgaricus. These observations suggest that non-pathogenic bacteria such as those used in food processing, can stimulate IFN production in mice. There is some evidence that the bacterial cell walls might be responsible for at least part of this effect.  相似文献   

17.
We showed that purified neuraminidase (NA) of influenza virus, but not hemagglutinin (HA), possessed the potential to increase in vitro and in vivo the interleukin 1 (IL 1) activity of mouse peritoneal macrophages. In this study, we report the effect of NA and HA on the secretion of tumor necrosis factor (TNF) activity by murine peritoneal macrophages. TNF being a cytokine sharing many related and overlapping biological functions with IL 1. The two glycoproteins of the strain A/USSR/90/77 (H1N1) were purified electrophoretically and were tested in vitro at doses ranging from 0.5 to 5.0 micrograms using the adherent peritoneal macrophages of C3H/HeN mice elicited with thioglycolate. The TNF activity of culture supernatants, collected 24 hr after stimulation with viral protein, was evaluated by the standard cytolytic assay using L929 and WEHI.164 cells. No increase of the TNF activity was observed at 0.5 micrograms of NA (4.8 Units (U)/ml in the L929 assay and 20.4 U/ml in the WEHI assay) but further increase of NA to 1.0 microgram had a significant effect on the TNF activity (39.7 and 88.8 U/ml, respectively). Higher concentrations of NA (2.0 and 5.0 micrograms) did not improve the TNF activity. The addition of a rabbit anti-TNF-alpha serum to the assay system reduced the lysis of L929 cells by 85%, suggesting that the observed activity was due to TNF. In parallel, the enhancement of IL 1 activity due to NA was reverified using D10.G4.1 cells instead of the C3H/HeJ thymocytes assay used previously. NA augmented the IL 1 activity up to 1.0 micrograms (25.8 U/ml). The addition of monoclonal anti-IL 1 antibodies (100 neutralizing units) to the supernatants reduced the incorporation of [3H]-thymidine by 90 to 95%, suggesting that the observed activity was due to IL 1. Comparative results of NA and HA showed that only NA stimulated the TNF and IL 1 activities of murine macrophages.  相似文献   

18.
Telomerase activity is not related to apoptosis in leukemic cell lines   总被引:6,自引:0,他引:6  
Zhang JX  Zhang ZK  Sheng HP  Tsao SW  Loh TT 《Life sciences》2000,66(18):1713-1723
  相似文献   

19.
Isoamylase production in batchwise and fed-batch cultures of Pseudomonas amyloderomosa (strain WU7211-2) was investigated. By feeding maltose in a mode motivated by its structure gene (iam), the final isoamylase activity of 5100 U/ml was achieved, as compared to 4100 U/ml in batch cultivation and 3800 U/ml in shaken flasks. The enhancement may be due to the fact that the production of isoamylase can be induced effectively by the maltose only if the glucose concentration is maintained below the inhibitory level. Also, cultivations based on 500-ml shaken flasks, performed with different amount of proteimax HE90, showed that higher amounts of proteimax HE90 resulted in an increased value of pH that had an adverse effect on isoamylase yield.The authors wish to thank the Food Industry Research and Development Institute (FIRDI), Taiwan, R.O.C for the financial support (Cooperative Agreement 94M904-2B). Appreciation is also extended to Drs. C.C. Liao, W.S. Chu and L.L. Lin of FIRDI for their valuable discussions.  相似文献   

20.
The effect of bombesin on insulin release from isolated pancreatic islets of rats was examined in vitro. Bombesin, at the doses ranging from 10 ng/ml to 1 microgram/ml, significantly inhibited 16.7 mM glucose-induced insulin release, while bombesin had no inhibitory effect on insulin release at 8.3 mM and 3.3 mM glucose. Moreover, bombesin also suppressed insulin release elicited by 10 mM arginine at the doses of 100 ng/ml and 1 microgram/ml. These results indicate that bombesin has a direct inhibitory action on insulin release.  相似文献   

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