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1.
Abstract

We have previously reported that a crude aqueous extract of the bitter melon (Momordica charantia) has both cytostatic and cytotoxic activi-ties 1,2, and is a competitive inhibitor of guanylate cyclase activity3. This crude preparation kills human leukemic lymphocytes in a dose-dependent manner while not affecting the viability of normal human lymphocytes at these same doses1.

In this report we describe the purification and characterization of one of these cytostatic factors which also exhibits anti-viral activity.

The partially purified factor was both cytostatic to BHK-21 cells and inhibitory to VSV plaque formation in a dose-dependent manner. This pre-paration was inhibitory to both viral and host cell RNA and protein synthesis as early as 30 min after addition to these samples. As determined by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), this purified factor is a single component with a molecular weight corresponding to 40,000 daltons.

The factor is sensitive to boiling and to pre-treatments with trypsin, but not ribonuclease (RNAse), or deoxyribonuclease (DNAse).

As determined by radioactive precursor uptake and incorporation studies, the purified factor inhibits both RNA and protein synthesis in intact tissue culture cells and inhibits protein synthesis in a cell-free wheat germ system4. DNA synthesis was slightly stimulated.

The purified factor is cytostatic for both BHK-21 and for the IM9 leukemic cell lines for at least 120 h.

The cytostatic component had no effect on cellular cyclic GMP metabolism.  相似文献   

2.
Abstract

A human-specific esterase was isolated from urine and partially characterized by ammonium sulfate precipitation, starch block electrophoresis, and gel filtration. Its molecular weight was estimated to be 136,000 by polyacrylamide gel electrophoresis in 0.17. SDS. A diffusion coefficient of 8.6 X 10?7 was determined by the L-plate method. Immunologic identity was shown between the urinary esterase and a human tissue esterase.  相似文献   

3.
采用硫酸铵分级沉淀、SP-Sepharose FF离子交换层析和Blue Sepharose CL-6B亲和层析获得苦瓜蛋白MAP30;采用(mPEG)2-Lys-NHS修饰MAP30;对修饰后的MAP30-PEG结合物与MAP30的抗肿瘤活性进行了比较分析。结果发现:MAP30对多数肿瘤细胞株具有明显的抑制作用,而且抑制效果在一定范围内具有剂量和时效依赖关系。但是在相同条件下,MAP30对人正常胚肺二倍体细胞株WI-38的毒性极小。MAP30和MAP30-PEG结合物对小鼠黑色素瘤(B16)、人宫颈癌细胞(Hela)和人表皮癌细胞(A431)细胞均表现出抑制作用,且这种作用在一定范围内呈时效和量效依耐性。但在相同浓度下PEG-MAP30对小鼠黑色素瘤(B16)、人宫颈癌细胞(Hela)和人表皮癌细胞(A431)的抑制作用低于MAP30,约占65%~70%左右。  相似文献   

4.
以‘碧绿3号’苦瓜幼苗为材料,采用100、500和1000μmol.L-1的水杨酸(SA)溶液预处理后进行白粉菌的诱导接种,研究了SA处理对苦瓜叶片光合色素含量和4个抗氧化酶活性的影响。结果显示:各浓度SA处理苦瓜植株的病情指数均显著低于对照(蒸馏水处理),并随SA处理浓度增加而逐渐下降;各SA处理苦瓜叶片的光合色素含量均高于其对照,且随SA处理浓度升高而逐渐增加;苦瓜叶片APX、CAT和GR活性随SA处理浓度增加而升高,但GPX活性反而下降,各处理CAT和GR活性增幅均高于病情指数增幅,1000μmol.L-1SA处理的APX活性增幅也高于病情指数增幅。研究发现,SA处理可以提高苦瓜感染白粉病植株叶片的光合色素含量及其抗氧化酶活性,显著降低其病情指数,增强其白粉病抗性,且以1000μmol.L-1SA处理效果最好。  相似文献   

5.
牛脑成纤维细胞生长因子的分离纯化与鉴定   总被引:3,自引:0,他引:3  
新鲜牛脑组织匀浆液经两步硫酸铵沉淀、CM-Sephadex C50 离子交换层析以及肝素-Sepharose 亲和层析,可得到纯化的酸性和碱性成纤维细胞生长因子(aFGF 和bFGF),分子量分别为13.2kD 和15.2—15.8kD.两种因子均可有效促进3T3细胞的 DNA 合成,ED50分别为15.8ng/ml 和 0.32ng/ml.进一步对 aFGF 的等电点及氨基酸组成做了分析.  相似文献   

6.
Previous studies carried out in our laboratory have demonstrated that goldfish brain contains substances that promote neurite extension from regenerating retinae in culture. Fractionation of the brain extract by molecular sieving chromatography revealed the presence of several molecular species, including two peaks that have neurotrophic activity, representing low-molecular-weight substances. One peak was eluted (P-a) with an apparent molecular weight of about 13 kDa and was designated substratum neurite extension factor (SNEF) because it retained its neurotrophic activity when adsorbed onto the substratum. This recovered Sephadex fraction (P-a) when applied in vivo intraocularly caused an earlier capacity of the corresponding retinae to sprout in vitro. Thus, at 3 and 5 days after injury the neuritic growth indices from the factor-treated retinae were of 0.9 +/- 0.2 and 2.8 +/- 0.5, respectively, as compared with indices of 0.3 +/- 0.1 and 0.9 +/- 0.2, respectively, in retinae of injured but nontreated nerves. The factor was further purified by two steps of HPLC (ion exchange followed by reversed phase). The results showed that it is an acidic glycoprotein with an apparent molecular weight of 10 kDa.  相似文献   

7.
8.
聚丙烯酸分离纯化苦瓜种仁碱性蛋白的方法及影响因素   总被引:1,自引:1,他引:0  
以苦瓜籽为材料,研究了聚丙烯酸分离纯化苦瓜种仁碱性蛋白的方法及影响因素。等电点沉淀试验表明,柠檬酸、盐酸分别调节苦瓜种仁粗提液pH至6.0、4.0时,各有14.62%和32.49%的苦瓜种仁蛋白被沉淀。醋酸的等电点沉淀作用呈现阶段性特点,pH6.0和4.0时分别有26.17%和38.72%的苦瓜种仁蛋白被沉淀。醋酸、盐酸和柠檬酸处理的1mL苦瓜种仁粗提液(pH4.0),1%PAA选择性沉淀碱性蛋白(等电点pI为8.65~9.30)的最佳用量分别为100μL、120μL和100μL。醋酸调节苦瓜种仁粗提液pH分别至5.0、4.0和3.0,等电点沉淀后的上清液用PAA沉淀碱性蛋白,当PAA(1%)用量为160μL/mL提取液时,pH5.0和3.0样液分别有33.77%和43.56%蛋白质被沉淀;当PAA用量为120μL/mL提取液时,pH4.0样液中30.83%蛋白质被沉淀。PAA-蛋白质复合物溶解于碱性溶液(pH>9.0),当溶液NaCl浓度为3.0%时,溶液蛋白质浓度最高。PAA选择性沉淀的苦瓜种仁碱性蛋白经SephadexG-75柱层析分离,分别在175min和300min出现主峰Ⅰ和Ⅱ。SDS-PAGE和IEF分析表明主峰Ⅰ的分子量约为30kD,pI值约为9.5,主峰Ⅱ的分子量约为10kD,pI值约为9.3。  相似文献   

9.
以苦瓜籽为材料,研究了聚丙烯酸分离纯化苦瓜种仁碱性蛋白的方法及影响因素。等电点沉淀试验表明,柠檬酸、盐酸分别调节苦瓜种仁粗提液pH至6.0、4.0时,各有14.62%和32.49%的苦瓜种仁蛋白被沉淀。醋酸的等电点沉淀作用呈现阶段性特点,pH 6.0和4.0时分别有26.17%和38.72%的苦瓜种仁蛋白被沉淀。醋酸、盐酸和柠檬酸处理的1mL苦瓜种仁粗提液(pH 4.0),1%PAA选择性沉淀碱性蛋白(等电点pI为8.65~9.30)的最佳用量分别为100μL、120μL和100μL。醋酸调节苦瓜种仁粗提液pH分别至5.0、4.0和3.0,等电点沉淀后的上清液用PAA沉淀碱性蛋白,当PAA(1%)用量为160μL/mL提取液时,pH5.0和3.0样液分别有33.77%和43.56%蛋白质被沉淀;当PAA用量为120μL/mL提取液时,pH 4.0样液中30.83%蛋白质被沉淀。PAA-蛋白质复合物溶解于碱性溶液(pH>9.0),当溶液NaCl浓度为3.0%时,溶液蛋白质浓度最高。PAA选择性沉淀的苦瓜种仁碱性蛋白经Sephadex G-75柱层析分离,分别在175min和300min出现主峰Ⅰ和Ⅱ。SDS-PAGE和IEF分析表明主峰Ⅰ的分子量约为30kD,pI值约为9.5,主峰Ⅱ的分子量约为10kD,pI值约为9.3。  相似文献   

10.
吸附法纯化苦荞麦总黄酮的工艺研究   总被引:2,自引:0,他引:2  
本文采用正交实验设计,对影响苦养麦总黄酮纯化工艺的因素进行了系统研究。结果发现,影响吸附法纯化苦养麦总黄酮的主次因素为吸附剂的种类〉洗脱液(乙醇)浓度〉静置吸附时间〉上样量,其中吸附剂的种类、洗脱液(乙醇)浓度以及静置吸附时间均对苦养麦总黄酮的纯化有显著性影响;吸附法纯化苦养麦总黄酮的最佳工艺条件为:AB-8树脂为苦养麦总黄酮最佳纯化吸附剂、95%乙醇洗脱、静置吸附时间30min、上样量1mL。  相似文献   

11.
12.
Ethanol-precipitated polysaccharides of the liquid endospermof coconut, Cocos nucifera L., were composed predominantly ofgalactose and arabinose with minor amounts of mannose and glucose.Gel filtration chromatography on Bio-Gel A-0.5 m revealed asingle major peak (Peak A) at the void volume and a minor peak(Peak B) partially included in the column volume. Peak A containedsome uronosyl residues, but was not susceptible to cleavageby endopolygalacturonase, indicating that it does not containsignificant amounts of polygalacturonic acid. Neutral glycosylresidue composition analysis of Peak A showed that it consistedof 72% galactose and 24% arabinose with minor amounts of glucoseand rhamnose. Coconut milk, Cocos nuciferaL, polysaccharides, glycosyl composition  相似文献   

13.
本研究设计了利用DEAE-52离子交换层析、Sephadex G-150凝胶过滤、以及经Ultrogel和DEAE-Sepharose CL-6B柱进一步层析分离获得高纯度人脑神经特异性烯醇化酶(NSE)的纯化方案。纯化的酶经SDS电泳鉴定为单一亚基区带,其亚基分子量约为45,000。NSE的等电点约为4.7。该酶作用2-磷酸甘油酸的km值为0.7mmol/L,对Mg~++的km值为0.7mmol/L。Mg~++为烯醇化酶必不可少的辅助因子。在50℃以下,NSE具有一定的热稳定性。  相似文献   

14.
This study reports the isolation and partial purification of a polypeptide from human saliva which causes a significant serum calcium lowering when administered to mice. Purification was achieved by preparative electrophoresis, dialysis, two gel filtration steps on Sephadex G-150, and ion exchange chromatography on DEAE-cellulose. Homogeneity was determined by poly-acrylamide electrophoresis. Blood sampling was carried out by puncture of the orbital venous plexus and serum analyzed for calcium. The most active preparations lower serum calcium from 10–27% of initial value, producing tetany and convulsions in some cases. The molecular weight of this polypeptide was estimated to be 4, 260 by the use of a calibrated Sephadex G-75 column. This is a much smaller molecular weight than that expected from its initial exclusion from Sephadex G-150, and suggests that this hypocalcemic factor is associated with larger molecules through most of the purification procedure up to and including DEAE-cellulose chromatography. A second gel filtration on Sephadex G-150 separates two minor salivary protein contaminants (IgA and IgG immunoglobulin) in the excluded fraction from the smaller, hypocalcemically active polypeptide.

No hypocalcemia activity could be detected or isolated in a preliminary investigation on the saliva of a dysgammaglobuli-nemic (IgA deficient) patient.

The hypocalcemia induced does not differ significantly from that observed after administration of calcitonin to mice in that: 2) minimum values are reached in 1.5–2 hours and return to normal in 5–6 hours, b) magnitude of hypocalcemia response is dose dependent. The salivary hypocalcemia factor isolated in this study has the properties of a protein, in that its activity is destroyed by the proteolytic enzyme trypsin, it yields amino acids upon acid hydrolysis and it behaves on electrophoresis, gel filtration and ion exchange chromatography as a typical protein.  相似文献   

15.
为探讨二氧化硅在大鼠肺内引发的一系列纤维增生反应,试图寻找一种关键的细胞增生因子,采用高压液相色谱技术,包括凝胶过滤柱层析、离子交换柱层析以及反相C4高压液相色谱柱层析,获得一种新的巨噬细胞源成纤维细胞生长因子(alveolarmacrophage-derivedfibroblastgrowthfac-tor,AMDGF),SDS-PAGE结果表明它已达到均一的纯度,其分子量为58000,pI为4.7.该因子的分子量与MΦ在体外接受石英粉尘刺激分泌的因子的分子量明显不同.N端序列测定结果显示它与已知蛋白序列的同源性小于50%,其刺激成纤维细胞增殖的最适浓度范围为2.0~6.0μg/ml,推测AMDGF是矽肺纤维化病变发生、发展过程中调节成纤维细胞增殖的重要因子之一  相似文献   

16.
Abstract

A more convenient synthetic route to 1-deazaadeno-sine starting from 7-nitroimidazo[4,5-b]pyridine 4-oxide is reported. 1-Deazaadenosine showed a good cytostatic activity in vitro.  相似文献   

17.
人胎肝超氧化物歧化酶的研究   总被引:1,自引:0,他引:1  
采用离子交换和凝胶过滤层析法,从正常人胎肝提取、纯化铜锌超氧化物歧化酶(Cu.Zn-SOD),并对其性质作了研究,结果测得人胎肝组织Cu·Zn-SOD平均含量为6.44unit/g湿重,并发现随着胎龄的增加人胎肝Cu.Zn-SOD含量上升;纯化后的Cu·Zn-SOD在聚丙烯酰胺凝胶电泳图谱上呈现单一区带;其活性受氰化钾抑制;以原子吸收光谱测得其铜、锌含量分别为0.39%和0.1%,采用SDS-聚丙烯酰胺凝胶电泳测得其亚基分子量为16kD;氨基酸自动分析仪测得其亚基的氨基酸残基数为151.5;在紫外吸收光谱上于265nm和258nm处分别出现两个吸收高峰。本研究结果表明,人胎肝Cu.Zn-SOD与成人肝及其他组织的Cu.Zn-SOD理化性质上基本一致。  相似文献   

18.
重组人粒细胞集落刺激因子(rhG-CSF)在工程菌pCG-1/rhG-CSF/DH5a中以无活性的包涵体形式大量表达。经过菌体破碎分离包涵体、包涵体变性复性后,rhG-CSF的活性得到恢复。用离子交换和疏水层析纯化了rhG-CSF,比活性达1.57×108u/mg,纯度大于98%。  相似文献   

19.
A system is described for producing recombinant factor X with properties very similar to human plasma factor X. Optimization of the expression system for factor X resulted in the finding that human kidney cells (293 cells) are superior to the widely utilized baby hamster kidney cells (BHK cells) for the expression of functional factor X. It was also determined that production of factor X by 293 cells requires the substitution of the −2 residue (Thr → Arg) which affords the removal of the factor X propeptide. Purification of recombinant and plasma factor X is accomplished using a calcium-dependent monoclonal antibody directed against the gla domain. The proteins are comparable by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The rate and extent of activation by the factor X coagulant protein from Russell's viper venom and by factors IXa and VIIIa are similar; activation of the recombinant protein by VIIa and tissue factor is mildly faster. The activated enzymes have the same activity toward a chromogenic substrate and the biologic substrate, prothrombin. Both enzymes have the same apparent affinity for the activated platelet surface as judged by their ability to activate prothrombin. Finally, inhibition by antithrombin, with or without heparin, and inhibition by the tissue factor pathway inhibitor are equivalent. Recombinant factor X produced by this method is therefore well suited for probing structure–function relationships by mutational analysis.  相似文献   

20.
苦杏仁精油的熏蒸杀虫活性研究   总被引:2,自引:0,他引:2  
采用三角瓶密闭熏蒸法测定了苦杏仁精油对家蝇、白纹伊蚊、粘虫以及玉米象的熏蒸杀虫活性,结果显示:苦杏仁精油对各试虫均有较强的熏蒸杀虫活性,其中含HCN的精油对家蝇、白纹伊蚊、粘虫以及玉米象的LC50分别为3.09、0.63、4.63、12.03μL/L;除去HCN的精油对家蝇、白纹伊蚊、粘虫以及玉米象的LC50分别为3.53、0.52、4.08、23.46μL/L;熏蒸的时间效应试验结果表明,含有HCN的苦杏仁精油和不含HCN的苦杏仁精油对供试试虫的熏杀速度均较快,其中白纹伊蚊的反应最快,其次为家蝇、粘虫、玉米象.除玉米象外苦杏仁精油中所含的微量HCN对试虫的熏蒸活性影响不大,且2种处理的精油对同种试虫的致死中时差别范围不超过10 min.实验结果表明,苦杏仁精油可作为新型的杀虫活性物质,为苦杏仁精油作为植物源杀虫剂提供了依据.  相似文献   

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