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     

糖链对蚯蚓纤溶酶纤溶活性的影响

应用以大豆胰蛋白酶抑制剂(SBTI)为配基的亲和色谱从赤子爱胜蚓中分离了蚯蚓纤溶酶,亲和介质Sepharose-4B对蚯蚓纤溶酶的吸附量为0.04 ms/g,以糖苷酶A去除固定在SBTI上的蚯蚓纤溶酶的糖链.辣根过氧化物酶标记的刀豆凝集素(ConA-HRP)亲和印迹和Schiffs染色结果表明.蚯蚓纤溶酶的糖链已基本去除,去除糖链后蚯蚓纤溶酶的活性降低约30%.     

蚯蚓纤溶酶的抗肿瘤作用

目的　观察蚯蚓纤溶酶 (EFE)对体外人癌细胞株及体内人癌裸鼠移植性肿瘤生长的影响 ,对该药进行临床前抗肿瘤药效学评价。方法　采用MTT法观察蚯蚓纤溶酶对体外人癌细胞的生长抑制作用 ;用人胃癌BGC82 3和人乳腺癌B37裸鼠移植性肿瘤模型对蚯蚓纤溶酶进行体内抗肿瘤药效学观察。结果　蚯蚓纤溶酶在体外对人癌细胞的生长无抑制作用 ;灌胃给予蚯蚓纤溶酶 2 0 0～ 10 0 0mg·kg-1,可明显抑制人胃癌BGC82 3和人乳腺癌B37裸鼠移植性肿瘤的生长。结论　蚯蚓纤溶酶具有抗肿瘤作用。     

均匀设计在蚯蚓纤溶酶肠溶片研究中的应用

应用均匀设计研究蚯蚓纤港酶肠溶片的处方和工艺，以片剂酶活力不改变为指标观察处方工艺，成功地获得了使蚯蚓纤溶酶活力基本不改变的肠溶衣片剂最佳处方和工艺。     

蚯蚓纤溶酶的研究进展及趋势

综述了蚯蚓纤溶酶的理化性质、酶学性质、药效学特性、化学修饰及分子生物学等方面的研究进展 ,提出了蚯蚓纤溶酶研究领域的发展方向。     

蚯蚓纤溶酶的纯化及pH值、温度和胰蛋白酶对其纤溶活性的影响

目的纯化并鉴定蚯蚓纤溶酶 ,研究pH、温度和胰蛋白酶对其纤溶活性的影响。方法以赤子爱胜蚓为材料 ,采用硫酸铵盐析、DEAESepharoseCL 6B离子交换色谱、SephadexG 75凝胶过滤和制备电泳等分离技术纯化蚯蚓纤溶酶 ;利用纤维平板和聚丙烯酰胺凝胶电泳研究pH、温度和胰蛋白酶对蚯蚓纤溶酶纤溶活性的影响。结果分离得到纤溶酶 4种单一组分 :EFE 1、EFE 2、EFE 3、EFE 4 ;分子量分别为 2 70 0 0、2 80 0 0、2 30 0 0、330 0 0 ;4种组分对温度的适应范围较广 ;pH值对其纤溶活性的影响不尽相同 ,但都在pH低于 1.5时纤溶活性完全丧失 ;胰蛋白酶对纤溶酶 4种组分均无降解作用 ,对其纤溶活性无影响。结论纤溶酶口服药制剂宜制成肠溶型     

蚯蚓纤溶酶的亲和层析纯化及部分性质

用牛血纤溶酶原Ｓｅｐａｒｏｓｅ４Ｂ亲和层析方法从蚯蚓粗提物丙酮粉中分离纯化一种纤维蛋白溶解酶。该酶为糖蛋白，含糖量约为１．４３％，Ｍｒ为３００００。实验结果表明此酶具有直接溶解纤维蛋白和激活纤溶酶原的间接溶解纤维蛋白的双重作用，并对人血凝块有明显的溶解作用。１％ＰＭＳＦ对酶有显著的抑制作用，说明此蚯蚓纤溶酶为典型的丝氨酸蛋白酶类酶。     

蚯蚓溶栓酶制剂的致突变研究

蚯蚓溶栓酶制剂的致突变研究山西医学院（０３０００１）孙天佑，谭佩娇，刘志艳，白桂花蚯蚓溶栓酶制剂是由双胸蚓组织中提取制备的多组分酶蛋白，含有多种纤维蛋白溶解酶及纤溶酶原激活物，具有抗凝、促纤溶作用，改善血液流变学功效（降低全血、血浆粘度及血小板聚集性...     

关于蚯蚓中所含溶栓酶稳定性的观察

目前市场上大力宣传并用于临床的药物溶栓胶囊,据介绍用冷冻干燥法从蚯蚓中制取的冷冻干燥粉,主要治疗脑血栓及脑血栓引起的后遗症……等.之所以用于血栓病是蚯蚓冷冻干燥粉中含有胶原酶,纤溶酶、纤溶酶原激活物.胶原酶主要作用于血栓坚硬的外壳胶原蛋白,使之切开分解而溶化.纤溶酶对血栓内部纤维蛋白发生降解作用,纤溶酶原激活物可激活纤溶酶原变成纤溶酶,加强降解血栓的作用,三者合用共同加速了血栓的溶解.     

快速蛋白液相色谱法纯化威廉环毛蚓纤溶酶及其活性研究

摸索威廉环毛蚓纤溶酶的分离纯化工艺和研究蚯蚓纤溶酶(earthw fibrinolytic enzyme，EFE)体内外的抗栓溶栓活性。通过提取，分步盐析，再经AKTAbasic蛋白快速液相色谱进一步纯化，得一组有纤溶活性的同工酶，其中一种比活较大达2000IU／mg。药理试验表明该酶有明显的抗拴溶栓活性。     

紫外分光光度法测定尼美舒利栓的含量

目的 :建立用紫外分光光度法测定尼美舒利栓中尼美舒利的含量。方法 :用不同的有机溶剂萃取尼美舒利栓中的基质 ,用紫外分光光度法测定尼美舒利的含量。结果 :用正己烷作为萃取剂。用紫外分光光度法测定尼美舒利栓的含量 ,标准曲线线性好尼美舒利线性范围为 3～ 15 μg·ml-1(r =0 .9999)、回收率较好 (98.3% )。结论 :用紫外分光光度法测定尼美舒利栓剂的含量 ,方法简便、快速、结果准确 ,可作为尼美舒利含量测定的方法。     

怡心力固体复合酶酶活力测定的最适反应条件研究

目的建立怡心力固体复合酶的酶活力测定方法。方法通过测量还原型辅酶Ⅰ(NADH)在340 nm波长处吸光度的变化来测定固体复合酶的酶活力。结果固体复合酶的最适酶促反应条件为pH 7.6的0.4 mol/L三乙醇胺缓冲液,NADH浓度为0.12 mg/mL,底物浓度为30 mg/mL,酶浓度为10 mg/mL。结论此法简便、准确,专属性强,可用于怡心力固体复合酶的酶活力测定。     

Substrate depletion approach for determining in vitro metabolic clearance: time dependencies in hepatocyte and microsomal incubations.

The substrate depletion method is a popular approach used for the measurement of in vitro intrinsic clearance (CL(int)). However, the incubation conditions used in these studies can vary, the consequences of which have not been systematically explored. Initial substrate depletion incubations using rat microsomes and hepatocytes were performed for eight benzodiazepines: alprazolam, clobazam, clonazepam, chlordiazepoxide, diazepam, flunitrazepam, midazolam, and triazolam. Subsequent predictions of in vivo CL(int) (ranging from 3 to 200 ml/min) and hepatic clearance (CL(H)) (ranging from 0.3 to 15 ml/min) demonstrated that the general predictive ability of this approach was similar to that of the traditional metabolite formation method. A more detailed study of the substrate depletion profiles and CL(int) estimates indicated that the concentration of enzyme used is of particular importance. The metabolism of triazolam, clonazepam, and diazepam was monoexponential at all cell densities using hepatocytes; however, with microsomes, biphasic depletion was apparent, particularly at higher microsomal protein concentrations (2-5 mg/ml). Enzyme activity studies indicated that enzyme loss was more pronounced in the microsomal system (ranged from 8 to 65% activity after a 1-h incubation) compared with the hepatocyte system (approximately 100% activity after a 1-h incubation). For clonazepam (a low clearance substrate), these biphasic profiles could be explained by loss of enzyme activity. To ensure accurate predictions of in vivo CL(int) and CL(H) when using the substrate depletion approach, based on the results obtained for this class of drugs, it is recommended that low enzyme concentrations and short incubation times are used whenever possible.     

Determination of soluble cAMP-dependent protein kinase activity in guinea-pig tracheal smooth muscle. Preferential use of kemptide as a phosphorylating substrate

A method is described for the determination of soluble (cytosolic) cyclic AMP (cAMP)-dependent protein kinase (A-kinase) activity in guinea-pig tracheal smooth muscle. The method relies upon the use of either histone or kemptide as a phosphorylating substrate. The relative merits of each of these substances were compared by studying the effects of a protein kinase inhibitor (PKI) and of Na+ on the phosphorylation of each substrate. PKI induced a concentration-dependent inhibition of basal and cAMP-stimulated phosphohistone formation but could not abolish it. Phosphokemptide formation was abolished by equivalent concentrations of PKI. Elevations in Na+ concentration in the reaction buffer inhibited cAMP-stimulated phosphohistone formation in a concentration-dependent manner with concomitant elevations in the enzyme activity ratio. Basal or cAMP-stimulated phosphokemptide formation was not inhibited by elevated Na+ concentrations. When tissues were homogenized in high Na+ concentration buffers, an increase in the basal A-kinase activity was observed using kemptide as the substrate. No apparent change in cAMP-stimulated activity was observed. Concomitant with this was an elevation in the enzyme activity ratio. However, a high Na+ concentration in the homogenizing buffer elevated basal phosphokemptide formation and the activity ratio. Separation of the isoenzymes of the enzyme yielded three peaks of activity upon assay of the fractions, which comprised free catalytic subunits (5% total activity), type I holoenzyme (5% total activity), and type II holoenzyme (90% total activity). Enzyme activity was increased upon pretreatment of tissues with isoprenaline and forskolin using both histone IIa and kemptide as phosphorylating substrates. The data support the preferential use of kemptide over histone IIa as a phosphorylating substrate during the determination of A-kinase activity in guinea-pig trachealis. The potential benefits of the use of kemptide are discussed.     

Optimization of Cultural Conditions for Protease Production by a Fungal Species

Studies were carried out on a paddy soil fungal isolate identified to be a strain of Aspergillus niger from Manipal. The parameters that largely impact enzyme production viz., fermentation time, impeller speed, pH, temperature and nutrient supplements were studied. Optimization of production parameters for production of protease was done by the single-parameter mode. Casein served as substrate and proteolytic activity was estimated using Folin-Ciocalteau method at 660 nm. A maximum yield of 71.3 mg tyrosine/g casein substrate was produced in 96 h on a soluble starch medium at pH 4 in shake flask experiments. Production was carried out on a 3-liter fermenter and 40.7 mg of tyrosine was liberated/g of substrate. The enzyme was extracted with 50% ammonium sulfate and sodium dodecyl sulfate-Polyacrylamide gel electrophoresis showed two bands having mw 45.7 kDa and 38.5 kDa, respectively. The enzyme activity was found to be 147.84 U/ml.     

Comparison of 2-aminophenol and 4-nitrophenol as in vitro probe substrates for the major human hepatic sulfotransferase, SULT1A1, demonstrates improved selectivity with 2-aminophenol

Sulfation, catalysed by members of the cytosolic sulfotransferase (SULT) enzyme family, is important in xenobiotic detoxification and in the biosynthesis and homeostasis of many hormones and neurotransmitters. The major human phenol sulfotransferase SULT1A1 plays a key role in chemical defence, is widely expressed in the body and is subject to a common polymorphism that results in reduced protein levels. Study of these enzymes in vitro requires robust probe substrates, and we have previously shown measurement of activity with the widely used SULT1A1 substrate, 4-nitrophenol, does not accurately reflect protein expression. Additionally, the high degree of substrate inhibition observed with this compound further reduces its value as a probe for SULT1A1. Here we show that 2-aminophenol is a more suitable probe substrate for quantifying SULT1A1 activity in human liver. This compound is sulfated at a high rate (V(max) with purified recombinant SULT1A1=121nmol/(minmg) and shows strong affinity for the enzyme (K(m) with purified recombinant SULT1A1=9microM) and, importantly, is a very poor substrate for the other major SULT1 enzyme expressed in liver, SULT1B1 (with V(max) and K(m) values of 17nmol/(minmg) and 114microM, respectively). Experiments with purified recombinant human SULTs and a panel of 28 human liver cytosols demonstrated that 2-aminophenol shows limited substrate inhibition with SULT1A1, and V(max) values measured in liver cytosols correlated strongly with SULT1A1 enzyme protein levels measured by a quantitative immunoblot method. We therefore suggest that 2-aminophenol is a suitable substrate to use for quantifying SULT1A1 enzyme activity.     

Dehydrogenation of indanol by rabbit liver 3-hydroxyhexobarbital dehydrogenase.

1. Among the several enzyme activities in rabbit liver cytosol able to dehydrogenate 1-indanol, only the main activity was not separable from 3-hydroxyhexobarbital dehydrogenase during purification including polyacrylamide gel disc electrophoresis. 2. Results of mixed substrate method indicated that the same enzyme catalyses the dehydrogenation of 1-indanol and 3-hydroxyhexobarbital. The ratio between the two dehydrogenation activities was almost constant as the enzyme underwent thermal inactivation. The Ki values of p-chloromercuribenzoate, the Km values for NAD+, and the Km values for NADP+ were very similar for the two dehydrogenations. These results lead to the conclusion that the same enzyme catalyses the dehydrogenation of 3-hydroxyhexobarbital and 1-indanol. 3. 1-Tetralol, 1-acenaphthenol, 9-fluorenol, thiochroman-4-ol and 4-chromanol also served as substrate of the enzyme, but 2-indanol, 2-tetralol, and trans- and cis-indan-1,2-diol were not oxidized. 4. Reversibility of the reaction was also confirmed using 1-indanone as substrate.     

几种因素在L-天冬酰胺酶化学修饰中对酶活力及抗原性的影响

为了寻求在较好地保持酶活力的同时解除L-天冬酰胺酶抗原性的方法,采用不同分子量的乙酸酐、右旋糖酐和单甲氧基聚乙二醇,作为修饰剂和不同的修饰方法对该酶进行了化学修饰。结果表明在保持酶活性和降低抗原性方面,大分子修饰剂右旋糖酐、单甲氧基聚乙二醇优于小分子乙酸酐,底物保护修饰优于直接修饰;活化PEG,优于活化PEG₁。在底物保护下的PEG,修饰酶其抗原性完全解除的同时,酶活力保持在30%以上。     

Purification and properties of a metyrapone-reducing enzyme from mouse liver microsomes--this ketone is reduced by an aldehyde reductase

A ketone reducing enzyme was purified to homogeneity from female mouse liver microsomes, using the diagnostic cytochrome P-450 inhibitor metyrapone as a substrate. In contrast to the usually employed indirect spectrophotometric recording of pyridine nucleotide oxidation at 340 nm, a HPLC method was applied for direct alcohol metabolite determination. Purification of the carbonyl reductase resulted in a 360-fold increase in specific activity together with a single band in the 34 kD region after SDS-polyacrylamide gel electrophoresis. Phenobarbital, indomethacin, dicoumarol and 5 alpha-dihydrotestosterone inhibited the enzyme, whereas quercitrin did not affect the enzyme activity. Thus, by inhibitor classification of carbonyl reductases the ketone metyrapone is reduced by an aldehyde reductase, rather than by a ketone reductase. Dihydrotestosterone, the strongest inhibitor, is supposed to be the physiological substrate for the purified enzyme. It was demonstrated that during the steps of purification both NADPH and NADH can supply the required reducing equivalents, although the activity with NADH is weaker. The highest activity was obtained using an NADPH-regenerating system. Ethanol and the nonionic detergent Emulgen 913 led to an increased specific activity, indicating that the enzyme is bound to the membranes of the endoplasmic reticulum in a latent state. From these results it is concluded that the microsomal metyrapone-reducing enzyme belongs to the family of carbonyl reductases, but differs from the common patterns of their classification with regard to cofactor requirement and inhibitor susceptibility.     

HPLC法测定灯盏花素片中灯盏花乙素的含量

目的建立灯盏花素片中灯盏花乙素的含量测定方法。方法采用高效液相色谱法,使用C18柱,流动相为甲醇-水-冰醋酸(30∶70∶1),检测波长335nm。结果该制剂中灯盏花乙素在0.0624～0.312μg范围内线性良好,平均回收率为99.92%,RSD为0.24%。结论该方法简便、快速、准确,可用于灯盏花素片的含量测定和质量控制。