白眉蝮蛇蛇毒纤溶酶的分离纯化

目的用白眉蝮蛇蛇毒分离纯化纤溶酶。方法利用离子交换层析、亲和层析、分子筛层析技术进行分离纯化纤溶酶。结果得到了电泳纯的纤溶酶,其相对分子质量为24000。结论该工艺可以快速地分离纯化白眉蝮蛇蛇毒纤溶酶：     

黑眉蝮蛇蛇毒纤溶酶的纯化及其性质研究

目的从黑眉蝮蛇蛇毒中纯化出无出血毒的纤溶酶。方法用DEAE-Sepharose FF阴离子交换树脂、CM-sepharose FF阳离子交换树脂和Sephacryl S-100凝胶过滤树脂三步分离方法,从黑眉蝮蛇蛇毒中纯化出一种纤溶酶活性成分。结果经SDS-聚丙烯酰胺凝胶电泳检测为单一蛋白质,相对分子质量为31 800,小鼠皮下注射无出血反应。该酶与纤维蛋白原保温15 min能迅速水解Bβ(β)链,随后缓慢水解Aα(α)链,而对γ(γ-γ)链无影响。结论此工艺可以快速纯化黑眉蝮蛇蛇毒纤溶酶。     

蚯蚓纤溶酶的分离纯化及抗栓活性研究

目的摸索蚯蚓纤溶酶的分离纯化工艺和研究蚯蚓纤溶酶的抗血栓活性。方法采用分步盐析、透析、凝胶色谱和亲和色谱法分离纯化蚯蚓纤溶酶 ;此酶的体内抗栓活性检测采用动静脉旁路血栓形成抑制实验法。结果分离纯化得到的蚯蚓纤溶酶比活高 ,为 16 0 5IU/mg ;蚯蚓纤溶酶的体内血栓形成抑制效果比尿激酶作用显著。 结论该法分离纯化工艺简单 ,特异性好 ,纯化的纤溶酶比活高 ;体内抗栓活性比尿激酶作用显著     

白眉蝮蛇蛇毒的分离纯化及综合利用

目的促进蛇毒的有效、综合利用。方法在分离纯化白眉蝮蛇蛇毒中降纤酶的试验过程中,同时分离纤溶酶。结果主要成分降纤酶的回收率为55.80%,纤溶酶的回收率为20.40%。结论该方法实现了对蛇毒宝贵资源的综合利用,为其综合开发利用探索了一条有效途径。     

长白山白眉蝮蛇蛇毒纤溶酶的纯化

从长白山白眉蝮蛇蛇毒中纯化具有溶栓功效的纤溶酶。方法：用 ＤＥＡＥ Ｓｅｐｈａｄｅｘ Ａ５０离子交换、Ｓｅｐｈａｄｅｘ Ｇ７５凝胶过滤层析和 ＤＥＡＥ Ｓｅｐｈａｄｅｘ Ａ ５０三步柱层析分离方法,对长白山白眉蝮蛇蛇毒进行分离纯化,得到了一种纤溶酶活性组分。结果：经ＳＤＳ－聚丙烯酰胺凝胶电泳和基质辅助激光解吸电离飞行时间质谱表征该酶为单一蛋白,其分子量为 ２３．３６７ ｋＤ。结论：为进一步研究其结构和功能提供了可靠依据。     

蛇毒纤溶酶原激活剂的研究进展

蛇毒是含有多种生物活性蛋白质和多肽的混合物,其中一些蛋白可作用于人的凝血系统。蛇毒纤溶酶原激活剂是具独特活性的蛇毒丝氨酸蛋白酶,具有较长的半衰期,可专一性地裂解人Glu-纤溶酶原的Arg^561-Val^562肽键,使之变成有活性的纤溶酶,从而发挥溶栓作用。该文主要对蛇毒纤溶酶原激活剂的结构特点和作用机制进行了阐述,旨在为新型溶栓剂的研究提供方向。     

蚯蚓纤溶酶的分离纯化研究

目的从赤子爱胜蚓(Eisenia Foelide)中分离纯化出一种相对分子质量(Mr)较小的纤维蛋白溶解组分———蚯蚓纤溶酶(EFE),为其注射剂的研制开发打下基础。方法采用盐析、透析、凝胶过滤色谱、离子交换色谱等方法分离纯化EFE,用SDS-PAGE对纯化的活性组分进行Mr测定,用酶谱分析方法初步探讨蚯蚓中存在的其它纤溶酶活性组分。结果分离纯化得到了EFE单一组分,经SDS-PAGE EFE呈单一条带,Mr约为25 000。经酶谱分析发现纤溶酶活性组分Mr分布在25 000~50 000之间。结论反复使用色谱技术可分离纯化EFE,并得到单一组分。     

国内蛇毒酶外用的研究进展

<正>蛇毒酶是以蛇毒为原料,经分离纯化提取的有效成分,由郝文学教授等首先从蛇岛腹蛇毒中提取成功。蛇毒酶包含各类水解酶、纤溶酶以及多种人体必需的微量元素,具有抗凝、溶栓、去纤、降脂、扩血管、改善微循环、抗衰老、抗血小板黏附聚积、促进神经细胞功能恢复[含有神经生长因子     

蛇毒中的抗血栓物质

蛇毒是含有多种蛋白质和多肽混含物,其中含有许多种影响血液系统功能的活性组分,本文从分布蛇毒的结构特点、活性和作用机制三个方面对蛇毒类凝血酶、蛇毒纤溶酶和蛇毒纤溶酶原激活剂等抗血栓成分加以综述。     

蛇毒纤溶酶溶栓作用的研究进展

蛇毒纤维蛋白(原)溶解酶(简称纤溶酶)主要通过降解纤维蛋白(原)而起到抑制血栓形成的作用,是一种潜在的强力溶栓剂.本文主要对近年来蛇毒纤溶酶的性质和溶栓机制的研究及其应用做一综述.     

Study of drug-protein binding by affinity chromatography: interaction of bovine serum albumin and salicylic acid

The affinity chromatographic technique was used to study the interaction of bovine serum albumin and salicylic acid at 3.3 +/- 1.1 degrees. Beaded agarose gel, on which the albumin was immobilized by covalent linkage, was packed in a column as an affinity adsorbent. Frontal analysis was performed on this column to evaluate the binding parameters for the interaction. The effect of albumin immobilization on drug binding was investigated by comparing the binding parameters of two affinity adsorbents, directly coupled albumin and albumin coupled through a spacer arm. The latter mode of attachment gave binding characteristics comparable to those of the soluble albumin. The method is simple and precise. The affinity adsorbent can be used repeatedly for many months for various drugs, including those that do not diffuse through dialysis membranes.     

两种融合蛋白的亲和柱上酶切

对两种融合表达的药物蛋白尝试了固相柱上酶切的方法,即Trx-r-PA、GST-IL-11融合蛋白分别在ETI-SepharoseFF、GST-Agarose亲和柱上酶切,酶切效率均高于液相酶切法.     

Single-step purification of epoxide hydrolase from rat liver microsomes using monoclonal-antibody chromatography

Monoclonal antibody to rat liver microsomal epoxide hydrolase has been obtained after immunization of mice with the enzyme prepared by conventional methods. Antibody from ascitic fluid was purified and coupled to CNBr-activated Sepharose 4B, to give a specific affinity column. Monoclonal-antibody affinity chromatography provided a rapid single-step method of purifying to homogeneity active epoxide hydrolase from crude solubilized microsomes. The techniques used offer an effective method for characterization of a non-inhibitory monoclonal antibody.     

白眉蝮蛇降纤酶的纯化及特性分析

目的从白眉蝮蛇蛇毒中提取降纤酶,并对其进行特性分析。方法采用一步亲和色谱法分离纯化降纤酶,用高效液相色谱分析其纯度,SDS-PAGE测定其相对分子质量。结果分离得到的降纤酶纯度高(99%以上),SDS-PAGE分析为一条带,相对分子质量为36 000,比活性为4 800 u/mg。结论用一步亲和色谱法从白眉蝮蛇蛇毒中纯化降纤酶的方法简单有效,所得产品纯度高、产量高。     

Pharmacological estimation of agonist affinity: detection of errors that may be caused by the operation of receptor isomerisation or ternary complex mechanisms.

1. Recent theoretical studies have questioned the pharmacological estimation of agonist affinity. They showed that when receptor isomerisation or ternary complex mechanisms operate, the receptor inactivation method can substantially overestimate affinity, whereas methods for partial agonist analysis are more accurate. We previously suggested that the operation of such mechanisms and therefore the presence of errors could be detected by analysing the same partial agonist by the receptor inactivation and comparative methods. This paper describes the practical application of this test. 2. The ternary complex mechanism was simulated for a partial agonist under various conditions relating receptor (R) and transducer (T) concentrations, one of which also corresponds to the receptor isomerisation mechanism. The theoretical data so generated were then analysed by the inactivation and comparative methods to quantify the magnitude of error of affinity estimation that could occur. 3. This analysis showed that for a partial agonist with approximately 85% of the activity of a full agonist, the inactivation method could produce an affinity (pKA) estimate up to 0.7 log10 units higher than that produced by the comparative method. This difference would occur when the total receptor concentration ([R0]) is less than or equal to the total transducer concentration ([T0]). It also showed that the overestimation of affinity by the inactivation method was accompanied by drastic overestimation of Em, the maximal effect parameter. 4. The test was then exemplified using the muscarinic receptor system in the guinea-pig isolated left atrial preparation, where there is evidence that a ternary complex mechanism operates. The test agonist was pilocarpine, which produced on average 83% of the activity of the full agonist, carbachol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Protein binding of piroxicam studied by means of affinity chromatography and circular dichroism

The protein binding of piroxicam, a widely used non-steroidal anti-inflammatory drug has been investigated by high-performance liquid affinity chromatography, with phenylbutazone and diazepam used as markers for binding-site characterization, and by circular dichroism titration. It was found that piroxicam binds to high-affinity phenylbutazone-binding sites and to high-affinity diazepam-binding sites. No binding to the low-affinity sites of either marker was established. High values of the primary (high-affinity) binding constants corresponding to both types of binding site were obtained by means of a mathematical method cited in the literature. The circular dichroic spectra of piroxicam were studied at a given albumin concentration and various drug concentrations. A new Cotton effect was observed and was ascribed to the binding of piroxicam to the protein molecule. The values of differential molar ellipticity (delta theta) were treated by a new mathematical procedure for analysis of the data obtained. A high affinity constant was calculated for one class of binding site. Its value is in good agreement with the values obtained by affinity chromatography. These results reveal that circular dichroism is an acceptable method for investigation of protein binding.     

Isolation of plasma kallikrein by high efficiency affinity chromatography and its characterization

We established a simple method for the purification of human plasma kallikrein (PK) by affinity chromatography and characterized it by analytical reverse phase-HPLC and Time of Flight Mass Spectroscopy (TOF-MS). The affinity resin (PKSI-Toyopearl) was synthesized using a selective synthetic inhibitor of plasma kallikrein (PKSI-527) as a ligand. The resin was found to have the highest efficiency in PK purification when the coupling ratio of PKSI-527 per resin was 9-14 micromol/g. PK was purified 466-fold with a yield of 83% from acetone-activated human plasma by affinity chromatography. The purity of PK thus obtained was confirmed by reverse phase-HPLC with a linear gradient of acetonitrile. The molecular weight of the purified PK was determined to be 86,151 by TOF-MS.     

The use of 4-diphenylacetoxy-N-(2-chloroethyl)-piperidine (4-DAMP mustard) for estimating the apparent affinities of some agonists acting at muscarinic receptors in guinea-pig ileum.

1. 4-Diphenylacetoxy-N-(2-chloroethyl)-piperidine (4-DAMP mustard), which is known to block muscarinic M3 receptors in preference to muscarinic M2 receptors, was used to estimate the apparent affinity constants of some agonists acting at muscarinic receptors in guinea-pig ileum. Estimates for carbachol and n-pentyl-trimethyl ammonium iodide were similar to published values obtained in similar conditions: those for n-hexyl-trimethyl ammonium iodide were slightly lower. 2. The results for the agonists, n-pentyl- and n-hexyl-trimethyl ammonium iodides and for the partial agonist, n-heptyl-trimethyl ammonium iodide were not as regular as was suggested by Stephenson, though there is an overall increase in apparent affinity with chain length. 3. Estimates of apparent affinity may be affected by hexamethonium, usually present in experiments on ileum. Its absence had little effect on the results with carbachol but reduced the estimates obtained with n-pentyl trimethyl ammonium, which has strong nicotinic effects compared with its muscarinic effects. On ileum treated with tetrodotoxin the values for n-pentyl trimethyl ammonium were similar to those obtained in the presence of hexamethonium (0.28 mM): slightly higher estimates of affinity were obtained in the presence of indomethacin (2.8 microM). The nicotinic effects of n-pentyl ammonium may involve the release of prostaglandins. 4. The estimates of apparent affinity did not depend on the method used to calculate them as the 'null' method and the 'operational' method give similar answers. Estimates of the transducer-ratio for the partial agonist, n-heptyl-trimethyl ammonium iodide, were numerically the same as those of its efficacy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Solubilization of rat liver alpha 1-adrenergic receptors. Agonist specific alteration in receptor binding affinity

An improved method for the solubilization of the alpha 1-adrenergic receptors in rat liver, utilizing digitonin, glycerol and sonication, is described. The yield of solubilized receptors was approximately 20%. The soluble receptors showed characteristics similar to the membrane-bound alpha 1 receptors. However, upon solubilization, the affinity for the agonists (-)norepinephrine and (-)epinephrine increased 35- to 66-fold when compared to the affinity in the membranes. The affinity for antagonists remained unchanged. A number of synthetic partial agonists showed a less marked (5- to 10-fold) increase in affinity upon solubilization. These data are consistent with the notion that these receptors might be capable of existing in two distinct conformational states with the high affinity state for agonists being favored by solubilization.     

Modification of the binding of sulphamidochlorobenzoic acid to human albumin by palmitic acid contamination of albumin

Summary Palmitic acid a common contaminant of albumin preparations, competitively inhibits the binding of sulphamidochlorobenzoicacid (SCBA) to human albumin thus decreasing its observed affinity. The effect of palmitic acid depends on its concentration, i.e. the purity and concentration of the albumin preparation used. The correct value for SCBA affinity was obtained by correcting the experimental data according to the palmitic acid concentration by use of a multiligand analysis method.