牡蛎酶解产物中多肽的分离纯化及其结构研究

目的从牡蛎蛋白质的酶解产物中分离制备具有活性的多肽并对其结构进行研究。方法采用胰蛋白酶对牡蛎蛋白质进行酶解,使其释放出具备特殊活性的肽,将含有活性肽的粗提物分别用Sephadex G25凝胶柱层析,DEAE-Sepharose FF离子交换柱层析和C18反相柱进行分离和纯化。结果牡蛎酶解产物经过分离纯化制备得到纯度较高的多肽F32,红外光谱的测定表明该肽的肽链是以α-螺旋的构型存在。电喷雾串联质谱法分析多肽F32完整的氨基酸序列为:Arg-Gln-Ile或Leu-Gly-Ala-Thr-Asn-Ala。结论本研究将为牡蛎酶解多肽F32构效关系的研究提供基础。     

生物活性肽的研究进展

从生理活性肽和食品感官肽两方面综述了生物活性肽的研究动态，同时对一些肽作了结构与功能的描述。     

生物活性肽的抗肿瘤作用及其机理研究进展

生物活性肽是一类天然存在于动、植物和微生物等生物体内,或动、植物蛋白质经蛋白酶酶解以及人工化学合成或生物工程方法而得,且具有特殊生理活性的生物物质,具有较显著的抗肿瘤作用。此文介绍了生物活性肽的分类与特性、抗肿瘤作用,并简述了生物活性肽增强机体特异性和非特异性免疫功能、抗自由基与辐射损伤、诱导肿瘤细胞凋亡和直接作用于肿瘤细胞等多种作用机理,并简述了生物活性肽实现抗癌以及临床抗肿瘤药用等内容。     

牡蛎活性肽的制备及其理化性质的初步研究

目的从牡蛎蛋白质的酶解物中分离制备活性肽并对其理化性质进行初步研究。方法采用胰蛋白酶对牡蛎蛋白质进行酶解,使其释放出具备特殊活性的活性肽,将含有活性肽的粗提物分别用Sephadex G25凝胶柱层析,DEAE-Sepharose FF离子交换柱层析和C18反相柱进行分离和纯化。结果牡蛎活性肽粗提物经过分离纯化制备出3个组分F31,F32,F41。组分F32,F41的等电点分别是7.12和7.08;组分F31,F32,F41的相对分子质量分别为885,810及409;其蛋白含量分别为51.9%,80.2%及99.8%;其糖含量分别为19.2%,4.3%及0%。结论以胰蛋白酶作用的最佳条件采用一步酶解的工艺,牡蛎蛋白质可以得到良好的酶解,同时得到的牡蛎活性肽粗提物活性较高。     

鸡源性活性肽的研究进展

随着我国鸡养殖和加工能力的提高,人们不仅追求鸡肉来源的营养成分,同时更需要提高其保健价值,其中鸡源性活性肽的生物活性及产业化应用备受人们关注.鸡源性活性肽不仅具有不同于蛋白质及氨基酸的消化吸收特性,还具有抗氧化、抗炎、免疫调节等诸多生物活性.此外,鸡肉加工副产物鸡骨、鸡皮、鸡血及鸡内脏等也是制备活性肽的主要原料,因而极...     

生物活性肽及其研究进展

生物活性肽来源广泛,目前已成为世界范围内的研究热点。生物活性肽具有显著的生理功能,如神经调节、激素作用、免疫调节、抗血栓、抗高血压、降胆固醇、抑菌、抗病毒、抗癌、抗氧化作用等,被誉为21世纪人类健康的新宠儿。本文综述了生物活性肽的种类、生理功能、吸收、制备、分离及研究进展,以期为生物活性肽的进一步研究和应用提供参考。     

海洋来源多肽生物活性及提纯方法研究进展

海洋生物来源的多肽,种类丰富,结构新颖,副作用小,是近年来研究的热点。本文主要对海洋生物来源的具有血管紧张素转化酶(ACE)抑制、抗氧化、抗菌、抗肿瘤和多功能活性肽进行综述,并对多肽的提取分离方法进行介绍,为进一步研究海洋生物活性肽提供参考。     

海洋生物活性肽研究进展

综述几种海洋天然生物活性肽的研究进展，阐明酶解生物活性肽的理论基础和海洋生物活性肽的吸收理论。对活性肽在养殖业中的作用、当前海洋生物活性肽研究的不足及研究前景作了评述。     

羊胚胎盘肽功能测试

目的探讨羊胚胎盘肽的制备及生物活性。方法应用膜技术制备羊胚胎盘肽 ,对羊胚胎盘肽的含量、肽谱、氨基酸、活性、紫外吸收等进行测试 ,利用动物实验观察羊胚胎盘肽对调节免疫、延缓衰老的作用。结果羊胚胎盘肽是一组小分子多肽 ,分子量小于 10 0 0 0D的占 37.3% ,紫外吸收峰在 194nm。结论羊胚胎盘肽具有调节免疫和延缓衰老的生物学活性     

β-酪啡肽的生理功能及其研究进展

酪蛋白是乳中最重要的成分.酪蛋白是乳源活性肽的重要来源,乳源生物活性肽是酪蛋白在消化酶作用下释放的,能被机体直接吸收,具有多种生物学功能.其中β-酪啡肽(β-casomorphin,β-CM)是最重要的乳源生物活性肽之一.该文就β-酪啡肽的生理功能及其作用进行综述,并介绍了国内外β-酪啡肽研究的情况及最新进展.     

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.     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

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.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.