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。     

五步蛇毒纤溶组分FⅨcaⅠ的分离纯化和生物活性的测定

目的从五步蛇(安徽产)毒分离纯化一种具有纤溶活性的组分FⅨcaⅠ,并研究其理化性质和生物活性。方法应用DEAE-Sephadex A-50阴离子交换层析、Sephadex G-75凝胶层析、Chelating Sepharose Fast Flow金属离子螯合亲和层析和Sephadex G-50凝胶层析四步分离纯化目的组分FⅨcaⅠ;纤维蛋白平板法和SDS-PAGE测定FⅨcaⅠ的生物活性;通过小鼠皮下注射不同剂量的FⅨcaⅠ,测量皮下出血斑的面积并求出最小出血剂量。结果从五步蛇毒分离纯化的FⅨcaⅠ组分为单体蛋白,相对分子量23 ku,等电点为4.8。FⅨcaⅠ可降解纤维蛋白和纤维蛋白原,优先降解α链,呈时效、量效关系。蛇毒纤溶酶FⅨcaⅠ最小出血剂量为54.9μg,为非出血性蛇毒纤溶酶。结论从五步蛇(安徽产)毒分离纯化的FⅨcaⅠ是一种分子量较小,比较稳定,纤溶活性强,可直接降解纤维蛋白且非出血性的新蛇毒纤溶酶。     

三种蛇毒类凝血酶对纤维蛋白原的作用方式

目的以纤维蛋白原为底物,考察巴西矛头蝮蛇(Bothrops atrox)、尖吻蝮蛇(Agkistrodon acutus)、长白白眉蝮蛇(Agkistrodon halys pullas)3种蛇毒类凝血酶对纤维蛋白原的作用方式。方法采用SDS-PAGE及RP-HPLC法对作用结果进行检测。结果 3种蛇毒类凝血酶对纤维蛋白原的作用方式不完全相同,巴西矛头蝮蛇、尖吻蝮蛇2种蛇毒类凝血酶只作用于纤维蛋白原的α链,对β、γ链则无作用,长白白眉蝮蛇毒类凝血酶起初作用于纤维蛋白原的β链,对α链作用较弱,随着时间的延长对α链作用增强,对γ链无作用。结论巴西矛头蝮蛇、尖吻蝮蛇2种蛇毒类凝血酶属于SVTLE-A型,而长白白眉蝮蛇毒类凝血酶则属于SVTLE-AB型。     

原矛头蝮蛇毒中一个新颖双链纤溶酶的分离纯化与性质研究

目的从原矛头蝮蛇毒中寻找新型纤溶酶,对其理化性质与生物学活性进行研究,以了解其在蛇伤中的作用与毒性机制,并评估其潜在的应用价值。方法采用蛋白层析技术分离纯化获得目标蛋白,检测其分子量、等电点、肽指纹图谱、多种蛋白水解活性、抗补体活性、出血活性、水肿活性及对流血时间的影响。结果通过阴离子交换层析、凝胶过滤层析、亲和层析从原矛头蝮蛇毒中纯化出一个酸性纤溶酶PMSP-A,它是由两条等电点分别为5.7与6.1的非均等肽链共价结合而成。SDS-PAGE和凝胶过滤测定其分子量分别为26.1 ku与25.3 ku。肽指纹图谱分析表明PMSP-A与黄绿烙铁头蛇毒中的血液凝固结合因子有部分序列吻合。PMSP-A能够依次降解纤维蛋白原的Bβ、Aα链,该活性能被PMSF、1,10-phenanthroline抑制,EDTA、EGTA、SBTI不能抑制其活性。PMSP-A具有纤维蛋白、精氨酸酯水解活性,没有偶氮酪蛋白水解活性。它还具有抗补体活性。动物实验表明,PMSP-A明显延长小鼠尾静脉流血时间,能诱导小鼠足趾轻度水肿,无皮下出血活性。结论 PMSP-A是一个新颖的原矛头蝮蛇毒双链丝氨酸蛋白酶,具有多种影响机体的生物学活性。     

蛇毒抗肿瘤蛋白心脏毒素的分离纯化与鉴定

目的:对蛇毒抗瘤蛋白的活性组分进行分离与鉴定。方法:采用 RP-HPLC 分离蛇毒抗瘤蛋白各组分,收集纯化组分Ⅱ。RP-HPLC 及 SDS-PAGE 测定组分Ⅱ的纯度;MALDI—TOF 质谱仪测定组分Ⅱ的相对分子质量;对组分Ⅱ进行 N-末端氨基酸序列测定。结果:蛇毒抗瘤蛋白组分Ⅱ经 RP-HPLC 和 SDS-PAGE 分析为单一成分,MALDI-TOF 质谱仪测得其相对分子质量为6719.49,其 N-末端氨基酸序列为 L-K-C-N-K-L-V-P-L-F-Y-K-T-C-P。结论:经分离鉴定,蛇毒抗瘤蛋白组分Ⅱ为心脏毒素。     

Agacutase体外水解牛纤维蛋白原机制的研究(英文)

Agacutase是自尖吻蝮蛇蛇毒中分离出的新的具有止血功能的蛇毒类凝血酶,它能够将纤维蛋白原转化为纤维蛋白单体。通过SDS-PAGE和ELISA方法,我们研究了Agacutase体外水解牛纤维蛋白原的分子机制。实验结果显示,Agacutase仅仅水解牛纤维蛋白原的α亚基并释放血纤肽A,而对牛纤维蛋白原的β和/或γ亚基没有影响。研究表明Agacutase属于血纤肽A类(FP-A类型)的类凝血酶。     

白唇竹叶青蛇毒5′-核苷酸酶对血小板聚集的影响及其机制研究

目的研究白唇竹叶青蛇毒5′-核苷酸酶对血小板聚集的影响,探讨其作用机制。方法采用比浊法测定白唇竹叶青蛇毒5′-核甘酸酶对二磷酸腺苷(ADP)、花生四烯酸(AA)、血小板活化因子(PAF)诱导血小板聚集的影响。结果白唇竹叶青蛇毒5′-核甘酸酶能抑制ADP、AA、PAF诱导的血小板聚集,且其抑制率与剂量增加成正比;抑制血小板聚集作用与ADP的水解和腺苷的积累有关。结论白唇竹叶青蛇毒5′-核甘酸酶能抑制血小板聚集,抑制作用主要通过水解ADP和积累腺苷,可能与阻断TXA2的生成有关。     

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。     

乌苏里蝮蛇毒一种C-型凝集素相关蛋白的分离、纯化及活性测定

目的从乌苏里蝮蛇蛇毒中分离纯化得到具有促凝血活性的C-型凝集素相关蛋白。方法利用IDA-Sepharose FF亲和色谱作为独立的蛋白分离纯化手段,并且结合Sephadex G-100,Sephadex G-50凝胶过滤色谱从乌苏里蝮蛇蛇毒中分离得到一个新的蛋白组分。结果该组分经还原和非还原SDS-PAGE电泳鉴定结果显示为均一的单一条带,即C-型凝集素相关蛋白,相对分子质量约为15.7 kD。结论经过一系列的分离和纯化,能够从乌苏里蝮蛇蛇毒中提取到C-型凝集素相关蛋白组分。     

蛇毒抗肿瘤蛋白化学成分的研究

对蛇毒抗肿瘤蛋白的化学成分进行研究。采用RP-HPLC分离蛇毒抗肿瘤蛋白各组分,收集纯化组分Ⅳ。非还原型SDS-PAGE和RP-HPLC鉴定组分Ⅳ的纯度;还原型SDS-PAGE与MALDI-TOF质谱仪测定组分Ⅳ的相对分子质量;测定组分ⅣN-末端氨基酸序列并进行Western blot鉴定;MTT法检测组分Ⅳ对体外培养的K562细胞的生长抑制作用。结果表明蛇毒抗肿瘤蛋白组分Ⅳ经SDS-PAGE和RP-HPLC分析为单一成分,MALDI-TOF质谱仪测得其相对分子质量为6714.22,其N-末端前5个氨基酸序列为L-K-C-N-K。经Western blot鉴定蛇毒抗肿瘤蛋白组分Ⅳ为细胞毒素,其对K562细胞的抑制作用呈明显的剂量依赖关系。     

Immunological properties of the fibrinolytic enzyme (fibrolase) from southern copperhead (Agkistrodon contortrix contortrix) venom and its purification by immunoaffinity chromatography

An antibody to the fibrinolytic enzyme in southern copperhead venom was produced by immunizing rabbits with chromatographically purified enzyme. The antibody was purified from rabbit blood by ammonium sulfate fractionation and protein-A affinity chromatography. The purified antibody reacted only with the fibrinolytic enzyme in southern copperhead venom as demonstrated by immunodiffusion and immunoelectrophoresis. Western immunoblotting revealed that several snake venoms, including Agkistrodon piscivorus conanti, Crotalus atrox, Crotalus basiliscus basiliscus, and Bothrops asper, cross-reacted with the antibody to varying degrees. However, Deinagkistrodon acutus showed no cross-reaction. Immobilized antibody has been used, in combination with molecular sieve chromatography, to purify the fibrinolytic enzyme from southern copperhead venom. In this two-step purification procedure, the enzyme was purified in good yield within two days. The specific activity of the enzyme purified by the immunoaffinity chromatography procedure is comparable with that of enzyme purified by a four-step chromatographic procedure. The mol. wt of the purified enzyme is approximately 23,000-24,000 as determined by SDS-PAGE. Interestingly, the enzyme purified by this two-step immunoaffinity chromatography procedure possesses virtually no hemorrhagic activity.     

A hemorrhagin as a metalloprotease in the venom of Trimeresurus purpureomaculatus: purification and characterization.

A major hemorrhagin was purified from the venom of the Thai green pit viper (Trimeresurus purpureomaculatus) by gel filtration, ion-exchange and affinity chromatography. A 15-fold purification was achieved with an overall yield of 7% of hemorrhagic activity. The hemorrhagin was homogeneous according to disc- and SDS-PAGE as well as on immunodiffusion. The molecular weight determined by SDS-PAGE was 72kDa. The purified hemorrhagin expresses proteolytic activity with heat-denatured casein and hide powder azure, but it was free of AE-hydrolase and phospholipase activities. Both hemorrhagic and proteolytic activities were inhibited by EDTA, suggesting that the hemorrhagin is a metalloprotease. The hemorrhagin hydrolyzed all gelatin preparations derived from types I, II, III and IV collagen, whereas it hydrolyzed only type IV native collagen. The hemorrhagic activity was neutralized by Thai green pit viper antivenom raised to Trimeresurus albolabris venom.     

Capacity of Thai green pit viper antivenom to neutralize the venoms of Thai Trimeresurus snakes and comparison of biological activities of these venoms

The capacity of Thai green pit viper antivenom raised to Trimeresurus albolabris to neutralize the venoms from six species of Trimeresurus sp. in Thailand has been examined. They were Trimeresurus albolabris, T. macrops, T. popeiorum, T. hageni, T. purpureomaculatus, and T. kanburiensis. The antivenom neutralized lethal and hemorrhagic activities of all these venoms. The capacity of antivenom to neutralize lethal toxicity of the venom was expressed as the amounts (mg) of snake venom neutralized by 1 ml of the antivenom. The largest capacity was found with the homologous venom. Results of immunodiffusion, immunoblotting, and antigen-antibody complex formation experiments supported the results of neutralization experiments. Several biological activities of the Trimeresurus venoms were also examined and compared. They were lethal, hemorrhagic, proteolytic, phospholipase A, arginine ester hydrolyse, and thrombin activities. There was no correlation between the ratios of lethal toxicity and hemorrhagic activity, lethal toxicity and phospholipase A activity, as well as hemorrhagic activity and proteolytic activity.     

Isolation and structural characterization of a new fibrin(ogen)olytic metalloproteinase from Bothrops moojeni snake venom.

A proteinase, named BmooMPalpha-I, from the venom of Bothrops moojeni, was purified by DEAE-Sephacel, Sephadex G-75 and heparin-agarose column chromatography. The enzyme was purified to homogeneity as judged by its migration profile in SDS-PAGE stained with coomassie blue, and showed a molecular mass of about 24.5 kDa. Its complete cDNA was obtained by RT-PCR and the 615 bp codified for a mature protein of 205 amino acid residues. The multiple alignment of its deduced amino acid sequence and those of other snake venom metalloproteinases showed a high structural similarly, mainly among class P-IB proteases. The enzyme cleaves the Aalpha-chain of fibrinogen first, followed by the Bbeta-chain, and shows no effects on the gamma-chain. On fibrin, the enzyme hydrolyzed only the beta-chain, leaving the gamma-dimer apparently untouched. It was devoid of phospholipase A(2), hemorrhagic and thrombin-like activities. Like many venom enzymes, it is stable at pH values between 4 and 10 and stable at 70 degrees C for 15 min. The inhibitory effects of EDTA on the fibrinogenolytic activity suggest that BmooMPalpha-I is a metalloproteinase and inhibition by beta-mercaptoethanol revealed the important role of the disulfide bonds in the stabilization of the native structure. Aprotinin and benzamidine, specific serine proteinase inhibitors, had no effect on BmooMPalpha-I activity. Since the BmooMPalpha-I enzyme was found to cause defibrinogenation when administered i.p. on mice, it is expected that it may be of medical interest as a therapeutic agent in the treatment and prevention of arterial thrombosis.     

蝮蛇毒纤溶酶的分离纯化及性质研究

目的 :寻找一种分离纯化蝮蛇毒纤溶酶的工艺并研究其理化性质。方法 :采用DEAE SepharoseCL 6B和HeparinCL 6B层析方法 ,从蝮蛇毒中分离纯化纤溶酶。结果 :蝮蛇毒纤溶酶经HPLC为单一峰 ,等电聚焦电泳为一条带 ,其等电点为 4.5 5 ,经SDS 聚丙烯酰胺凝胶电泳测得分子量为 2 9.4kD。该酶对热不稳定 ,在 pH6～ 9时稳定 ,氨基酸组成分析表明含酸性氨基酸较多。结论 :用此工艺可制得高纯度的蝮蛇毒纤溶酶。     

The properties of the purified fibrinolytic principle from Agkistrodon acutus snake venom.

The properties of the purified fibrinolytic principle from Agkistrodon acutus snake venom. Toxicon15, 161–167, 1977.—In addition to fibrinolytic, fibrinogenolytic and caseinolytic activities, the purified fibrinolytic principle of Agkistrodon acutus venom possessed hemorrhagic activity. Trasylol had a much higher inhibitory action on the fibrinolytic activity of the fibrinolytic principle of the venom than did ε-aminocaproic acid. Thus, the fibrinolytic action of the fibrinolytic principle was chiefly due-to a direct action on fibrin. Both EDTA (5 × 10^-4 M) and cysteine (5 × 10^-3 M) completely inhibited the fibrinolytic, fibrinogenolytic, hemorrhagic and caseinolytic activities of the fibrinolytic principle of the venom. Disulfide bonds might be essential for the biological activities of the fibrinolytic principle.     

N-terminal amino acid sequences and some characteristics of fibrinolytic/hemorrhagic metalloproteinases purified from Bothrops jararaca venom.

We determined the N-terminal amino acid sequences of the fibrinolytic/hemorrhagic metalloproteinases (jararafibrases I, III and IV) purified from Bothrops jararaca venom. The N-terminal amino acid sequences of jararafibrase I and its degradation products were identical to those of jararhagin, another hemorrhagic metalloproteinase purified from the same snake venom. Together with enzymatic and immunological properties, we concluded that those two enzymes are identical. The N-terminal amino acid sequence of jararafibrase III was quite similar to C-type lectin isolated from Crotalus atrox, and the protein had a hemagglutinating activity on intact rat red blood cells.