固定化胰蛋白酶的性质研究

目的　测定固定化胰蛋白酶的催化特性和部分稳定性。方法　在相同的条件下,测定固定化和可溶性胰蛋白酶的活力,得其最适作用pH值和最适作用温度,再测定活力,得到各自的米氏常数(Km)值;测得两种状态酶的热稳定性和酸碱稳定性。同时测定了固定化胰蛋白酶的低温稳定性。结果　固定化和可溶性胰蛋白酶的最适作用pH值分别为8 .0～9. 0和7. 0～9.0 ,最适作用温度分别为6 0℃和5 5℃,Km值分别为2 . 32 6、1 42. 9mg·ml-1 ;固定化胰蛋白酶在5 5℃条件下,保温5h ,仍有78 92 %的活性;在4℃条件下,8d后,活性才略微下降,两周活性保留达90 %以上;在pH 9.0的活性未下降,在pH 7.0～1 0 .0范围内也比较稳定(相对活性>80 %)。结论　胰蛋白酶经固定化后,最适作用pH值范围变窄,最适作用温度和Km值升高;热稳定性和酸碱稳定性均有所增强     

温敏载体固定化木瓜蛋白酶的特性及其消化HCG抗体的应用

以温敏性材料N-羟基琥珀酰亚胺活化的聚(N-异丙基丙烯酰胺)为载体制备固定化木瓜蛋白酶,对其酶学性质进行了研究。结果表明:固定化酶的最适pH值为7.5,最适温度为65℃,米氏常数为2.72 mg/mL;经过24次温敏循环操作,剩余相对活力86.6%;在4℃条件下放置60 d,剩余相对活力为71.5%。与游离酶相比,固定化酶pH值稳定性、热稳定性、操作稳定性和储存稳定性都有显著提高。将此固定化酶应用于HCG单克隆抗体消化,与纤维素固定化酶相比,水解能力更强,更适合于大分子的酶解,特别是抗体片段的制备。     

肝素黄杆菌的明胶固定化

研究以明胶为载体、戊二醛作为交联剂制备固定化肝素黄杆菌的方法,并考察其固定化条件和酶学性质。论文对肝素黄杆菌细胞进行了缺壁处理,通过对明胶浓度、戊二醛浓度等条件的筛选和研究,确定了制备固定化肝素黄杆菌的最佳条件。此外,还对固定化细胞的酶学性质进行了初步研究,考察了温度、pH等因子对固定化细胞的影响。结果表明:明胶浓度15%、戊二醛浓度1.0%、1 mL明胶溶液固定0.3 g细胞,是最佳固定化条件;固定化细胞的最适温度37℃,最适pH 7.0,其酸碱稳定性与温度稳定性均得到了提高。综上所述,肝素黄杆菌在最佳条件下固定化后,具有较好的温度、酸碱、操作和贮藏稳定性。     

青霉素酰化酶提取及其与固定化酶的动力学参数测定和比较

采用冻融-溶媒法从大肠杆菌中提取青霉素酰化酶(经硫酸铵沉淀、透析、冷冻干燥),制得酶粉,活力为1100.37u/g,经六批提取试验,平均提取收率47.93％。分别测定游离酶及其固定化酶米氏常数Km值。游离酶的Km值为2.39mM,固定化酶按其颗粒大小不同,Km值分别为5.62、8.46、8.42mM。 在对pH稳定性测定中,游离酶最适pH为7～8,而固定化后在pH5～9之间都较稳定。对温度的稳定性测定中,游离酶与固定化酶在40℃以下都较稳定,但在45℃保温一小时后,游离酶只存留活力39.51％,而固定化酶却存留活力86.92％,二者有显著差异、温度再高相差更大。因此酶经固定化后,对pH和温度的稳定性都有明显提高。金属离子对青霉素酰化酶的活力有所影响。特别是铁离子和铜离子影响较大,故酶反应容器不能采用铁和铜的材料。     

壳聚糖珠固定化乳糖酶的条件及特性研究

目的研究乳糖酶的固定化。方法以壳聚糖珠(2.0 g)为载体,0.02%戊二醛为交联剂,考察固定化乳糖酶的条件及其特性。结果固定化条件:室温状态下,在pH 6.0、酶量0.2 mg/mL的酶液中固定12 h,固定化乳糖酶活力回收率为31.5%。乳糖酶、固定化乳糖酶的最适pH值分别为5.0~5.5,5.5~6.5;最适温度分别为40℃,50℃。结论固定化乳糖酶最适温度和pH值比溶乳糖高。     

载门冬酰胺酶的自组装聚乙二醇-透明质酸/二甲基-β-环糊精纳米粒体外稳定性的初步考察

采用聚乙二醇接枝透明质酸和二甲基-β-环糊精制备了含载门冬酰胺酶(1)的自组装纳米粒(THDCD),并比较其与游离1在体外的活性及稳定性.测定了THDCD和1的最适温度、最适pH值,并对比了二者的酸碱稳定性、热稳定性、贮存稳定性、血浆稳定性、抗胰蛋白酶水解能力、抗部分金属离子及有机化合物影响的能力.结果表明,THDCD的最适温度和最适pH值为50℃和pH 6.5,而1为60℃和pH 7.5.THDCD的上述稳定性和抗性均优于1.本试验表明,THDCD在提高了1体外活性的同时,也显著增强了1的体外稳定性.     

天门冬酰胺酶聚乙二醇-透明质酸/磺丁基-β-环糊精纳米粒体外稳定性的初步研究

目的 制备含载天门冬酰胺酶(Asp)的自组装聚乙二醇-透明质酸/磺丁基-β-环糊精纳米粒(THSCD),并初步研究两者在体外的活性以及稳定性.方法 采用自组装法制备THSCD;分别从最适温度、最适pH、酸碱稳定性、热稳定性、贮存稳定性、血浆稳定性、抗胰蛋白酶水解能力、部分金属离子及有机化合物影响来考察THSCD中Asp和游离Asp的差异.结果 THSCD的最适温度为50℃,游离Asp最适温度为60℃.THSCD的最适pH为6.5,游离Asp的最适pH为7.5.THSCD的热稳定性、贮存稳定性、酸碱稳定性、血浆稳定性测定、抗胰蛋白酶水解能力和抗部分金属离子和有机化合物能力均比游离Asp好.结论 THSCD在提高了Asp在体外活性的同时,也明显地增强了游离Asp在体外的稳定性.     

CM-纤维素固定化脂肪酶的研究

目的 　研究 CM-纤维素为载体的固定化脂肪酶的制备方法及比较固定化脂肪酶与游离酶在酶学特性上的变化。方法 　制备固定化脂肪酶的最适条件是 p H5 .5 ,离子浓度为 0 .0 1mol· L- 1 的柠檬酸缓冲液 ,加酶量为 10 0μ· g- 1 载体 ,固定化反应时间为 8h。结果 　所得的固定化酶酶活力为 49.6μ·g- 1载体 ,回收率为 45 % ,最适作用 p H值为 10 .6,最适作用温度为 46℃ ,其催化油脂水解操作半衰期为 2 2 5 h。结论 　本固定化酶制备简便 ,可重复使用 ,稳定性较高。     

固定化β-葡萄糖苷酶制备人参皂苷F_1的研究

本文探讨了β-葡萄糖苷酶的固定化方法,及利用固定化β-葡萄糖苷酶转化人参皂苷Rg1为人参皂苷F1的转化工艺。确定交联-包埋法为最佳固定化方法,应用正交实验得出最佳制备条件为:交联时间3h,戊二醛浓度0.1%,海藻酸钠浓度1%,CaCl2浓度2%。固定化酶与游离酶在热稳定性和pH值稳定性方面显示出不同的性质,其中固定化β-葡萄糖苷酶的最适反应温度为70℃,最适反应pH值为5.5。固定化β-葡萄糖苷酶在15℃环境中保存30d后,酶活回收率为68.82%。固定化β-葡萄糖苷酶转化人参皂苷Rg1为人参皂苷F1的转化条件为:固定化酶承载量为3.76U/g固定化酶载体,底物浓度为0.2mg/mL,转化温度为40℃,转化周期为2d,转化次数为4次,平均转化率为80.49%。     

壳聚糖固定谷氨酸脱羧酶的研究

以壳聚糖为载体，戊二醛为交联剂。制备固定化谷氨酸脱羧酶(GDC)，研究固定化反应中pH值、戊二醛浓度、给酶量以及交联反应搅拌时间对固定化GDC活力的影响以及GDC固定化酶和自由酶的酶学特性。实验结果表明：壳聚糖固定化GDC的最适pH4．4．最适温度55℃。与自由酶相比。具有较好的热稳定性、贮存稳定性及可操作性；在米胚芽生产制备γ-氮基丁酸中具有实用价值。     

Nachweis einiger Heilmittel in der Kniegelenksynovialflüssigkeit

Zusammenfassung Mittels Gaschromatographie und Dünschichtchromatographie wiesen die Autoren 11 Substanzen nach, welche durch Injektion oder nach Verabreichung per os in die Kniegelenksynovialflüssigkeit eindrangen. In ihrer Aufstellung konnten sie eine direkte Beziehung zwischen Struktur sowie chemischphysikalischen Eigenschaften der Substanz und ihrer Fähigkeit, aus dem Blut in die Kniegelenksynovialflüssigkeit einzudringen, nicht nachweisen, außer der Tatsache, daß Substanzen mit starker Affinität zu Eiweißstoffen erst in höheren Dosen nachweisbar waren.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Emerging drugs for epilepsy

Epilepsy affects ≤ 1% of the world's population. Antiepileptic drugs (AEDs) are the mainstay of treatment, although more than a third of patients are not rendered seizure free with existing medications. Uncontrolled epilepsy is associated with increased mortality and physical injuries, and a range of psychosocial morbidities, posing a substantial economic burden on individuals and society. Limitations of the present AEDs include suboptimal efficacy and their association with a host of adverse reactions. Continued efforts are being made in drug development to overcome these shortcomings employing a range of strategies, including modification of the structure of existing drugs, targeting novel molecular substrates and non-mechanism-based drug screening of compounds in traditional and newer animal models. This article reviews the need for new treatments and discusses some of the emerging compounds that have entered clinical development. The ultimate goal is to develop novel agents that can prevent the occurrence of seizures and the progression of epilepsy in at risk individuals.     

盐酸达泊西汀中甲磺酸甲酯、甲磺酸乙酯及甲磺酸异丙酯的顶空毛细管GC-ECD法测定

建立了衍生化顶空毛细管气相色谱-电子捕获检测器(ECD)法测定盐酸达泊西汀中的甲磺酸甲酯(MMS)、甲磺酸乙酯(EMS)和甲磺酸异丙酯(IMS).应用碘化钠衍生技术,使用PW-5毛细管柱,载气为氮气,ECD检测,程序升温.MMS、EMS和IMS分别在0.03～0.30、0.05～0.50和0.05～0.50 μg/ml浓度范围内线性关系良好,平均回收率分别为63.5％、100.3％和96.2％,最低检测限分别为0.30、0.50和0.50 ng/ml.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.