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1.
安舒克栓酶(Antithromboase,AT)是本实验室从枯草杆菌N18中分离得到的具有强烈水解纤维蛋白活性的蛋白酶.研究表明,该酶具有直接纤溶和纤溶酶原激活剂的双重作用,且有较强的纤维蛋白亲和性,是极具开发价值的溶栓药物.来源于医用水蛭的水蛭素(hirudin,Hir)是凝血酶的最强有力的天然抑制剂,是极具优势的抗凝药物.但仍各有不足:安舒克栓酶只有溶栓功能,不能抗栓,不能解决血栓治疗中再栓塞的问题;水蛭素只有抗凝作用,不具溶栓功能.如果将这两种从不同途径治疗血栓的药物.通过融合  相似文献   

2.
抑肽酶属Kunitz抑制剂家族成员,能够抑制激肽释放酶、纤溶酶及胰蛋白酶的蛋白水解活性.研究表明,抑肽酶能够抑制尿激酶型-纤溶酶原激活刹(u—PA)和组织型纤溶酶原激活剂(t—PA)对纤溶酶原的激活,但不影响u—PA和t—PA对小分子底物的酰胺水解活性.用u—PA研究了上述作用的机制,发现抑肽酶与u—PA的丝氨酸蛋白酶功能区特异性结合,而与纤溶酶原没有相互作用.抑肽酶与uPA的结合并不阻断u—PA的活性位点,因为u—PA对小分子底物的水解活性仍然保持.上述发现提示抑肽酶可能存在另一种抑制作用模式,该模式不同于以前报道的关于Kunitz抑制剂或纤溶酶原激活酶抑制剂的作用.由于人体内的Kunitz抑制剂与抑肽酶在结构上非常相似,根据研究结果,推测体内纤溶酶原的激活作用并非仅受丝氨酸蛋白酶抑制剂的控制。  相似文献   

3.
蚯蚓纤溶酶的分离纯化及性质鉴定   总被引:4,自引:0,他引:4  
以赤子爱胜蚓为材料,经过硫酸铵盐析、DEAE-Sepharose CL-6B离子交换层析、Sephadex G-75凝胶过滤和制备电泳分离得到四种纤溶酶组分.经PAGE鉴定四种组分为单一组分;SDS-PAGE测定其分子质量分别为27、28、23和33ku;等电点均在4.0以下;经甲苯胺蓝染色后都出现糖蛋白的阳性反应;用苯酚一硫酸法测定其中性糖含量分别为8.4%、13.5%、9.1%、6.8%;纤维平板法测得四种组分的活性存在明显差异;四种组分都具有直接溶解纤维蛋白和激活纤溶酶原的双重作用.pH值对四种组分纤溶活性稳定性的影响各不相同.四种组分对温度的适应范围较广.  相似文献   

4.
在生化实验的基础上,利用数值模拟初步研究了纤维蛋白溶酶在凝血过程中的动力特征作用,并研究了凝血酶与纤溶酶在生化反映中的相互关系,得到了一些新的结论,这些结论将为血液学与临床实践提供有益的启示,同时也显示出数值模拟方法的实用性.  相似文献   

5.
尿激酶原催化纤溶酶原的激活包括3个反应:(1)尿激酶原内在酶活性催化纤溶酶原转化为纤溶酶;(2)纤溶酶激活尿激酶原变成尿激酶;(3)尿激酶激活纤溶酶原,所以一直以来人们对尿激酶原激活纤溶酶原的过程知之甚少.研究发现EACA可以抑制尿激酶原催化的纤溶酶原激活。通过EACA对上述3个反应的影响进行逐个分析,观察到在EACA浓度为2.0mmol/L时,尿激酶原内在酶活性催化纤溶酶原激活的反应速度提高了4.5倍,尿激酶激活纤溶酶原的反应速度提高了6倍.相反地,纤溶酶激活尿激酶原变成尿激酶的反直被抑制了50%,此反应决定了EACA对尿激酶原催化纤溶酶原激活反应的抑制作用.该结果提示尿激酶原催化纤溶酶原激活反应的限速步骤是纤溶酶激活尿激酶原变成尿激酶,缘于纤溶酶和尿激酶原的赖氨酸结合位点的相互作用.  相似文献   

6.
D--二聚体是纤维蛋白单体经活化因子ⅩⅢ交联后,再经纤溶酶水解产生的特异性降解产物,其血浆浓度增高反映凝血酶生成增多和继发性纤溶活性增强,它可作为体内高凝状态和继发性纤溶亢进的标志之一,也是判断溶栓疗效的有效指标.  相似文献   

7.
脉孢菌纤溶酶的纯化和性质初步研究   总被引:1,自引:0,他引:1  
应用超滤、盐析、凝胶过滤和疏水相互作用层析对脉孢菌产纤溶酶初步纯化后,活性电泳证实获得单一的纤溶活性组分。对该纤溶组分的基本酶学性质作了进一步的研究,结果表明该纤溶酶的最适作用温度和最适pH分别是46℃和7.8,在40℃以下和pH6.2~7.8时稳定,该纤溶酶具有直接和间接的纤溶活性。  相似文献   

8.
赵玉梅  李东燕 《甘肃科技》2000,16(2):51-51,64
D———二聚体是纤维蛋白单体经活化因子XIII交联后 ,再经纤溶酶水解产生的特异性降解产物 ,其血浆浓度增高反映凝血酶生成增多和继发性纤溶活性增强 ,它可作为体内高凝状态和继发性纤溶亢进的标志之一 ,也是判断溶栓疗效的有效指标。近年来将D———二聚体作为高凝和继发性纤溶的分子标志物 ,应用到心脑血管疾病 ,作为血栓预告的标志之一。为了探讨缺血性脑血管病、脑出血和正常老年人的D———二聚体的变化及脑血管病判断、治疗 ,将我院检查确诊脑血管病患者观察结果报告如下。1资料和方法1.1资料1.1.1健康人对照 :30例…  相似文献   

9.
蚌蛙蛭抗凝血蛋自的分离及抗凝血特性(英文)   总被引:2,自引:1,他引:1  
以超速离心和肝素琼脂糖亲和层析从蚌蛙蛭(Batracobdellakasmiana)的粗提取液中分离到2种抗凝血蛋白.抗凝血活性测定证明,这2种蛋白具有显著抑制凝血酶的活性而不具有抑制凝血因子Xa的活性.亲和层析的蛋白洗脱峰与抑制凝血酶的活力峰相吻合;因此,蚌蛙蛭的抗凝血蛋白是属于凝血酶特异性的抗凝血蛋白.这为进一步研究蚌蛙蛭抗凝血蛋白的抗凝血机理及其应用打下了基础.  相似文献   

10.
报告了一实用的凝血酶抑制剂抑制活性的测定方法——发色底物分光光度法;以发色底物S—2238与标准凝血酶反应,测定未抑制的吸光度Ao,同时以发色底物S—2238与凝血酶抑制剂盐源山蛭素和标准凝血酶反应测定抑制吸光度As,然后以As/Ao计算盐源山蛭素的抑制活性a1.实验证明,这种对盐源山蛭素抑制活性的测定方法简便易行、重复性高、偶然误差小、可信度高.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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