蛇毒血小板聚集抑制剂的研究进展

蛇毒血小板聚集抑制剂的研究进展孙林光综述管锦霞审校（广州医学院广州蛇毒研究所广州,５１０１８２）血小板是血液中最小的、具有多种功能的细胞,它在生理性止血以及血栓形成、动脉粥样硬化等病理过程中起着重要的作用［１］。蛇毒中广泛存在抑制血小板聚集的活性组分...     

白眉蝮蛇去整合素Adinbitor的基因克隆、表达及其部分生物学活性

为了寻找去整合素家族的新成员 ,研究其在抗血栓与抗肿瘤等方面的作用 ,从中国白眉蝮蛇毒腺中提取总RNA进行RT PCR扩增 ,获得了 2 19bp的白眉蝮蛇去整合素基因 .测序结果显示 ,其与韩国的同为蝮蛇去整合素的saxatilin的DNA序列同源性为 95 8% ,蛋白质序列同源性为 91 8% ,且蛋白质中含有去整合素的特征模体 RGD .将去整合素基因进行克隆、转化与诱导后 ,得到了该蛋白的可溶性高效表达 .经组氨酸亲和层析纯化 ,获得了分子量为 9kD的均质蛋白 ,并将其命名为adinbitor .活性测定结果显示 ,adinbitor能明显抑制由碱性成纤维细胞生长因子诱导的人脐静脉血管内皮细胞ECV30 4的增殖 ,诱导ECV30 4细胞发生凋亡 ,并且呈剂量依赖性方式抑制ADP诱导的人血小板聚集     

蛇毒抗肿瘤组分的研究进展

介绍了近几年来蛇毒在抗肿瘤作用方面的最新研究进展。蛇毒抗肿瘤的机制主要有三种：细胞毒作用、阻断整合素及诱导细胞凋亡。本文概述了近年来从不同种蛇毒中分离获得的具有抗肿瘤活性的组分。     

重组白眉蝮蛇去整合素定点突变对其生物活性的影响

RGD为存在于许多糖蛋白配体中的氨基酸序列,对整合素具有识别作用.此序列也发现于许多蛇毒去整合素分子中.采用基因克隆技术从大连产白眉蝮蛇的毒腺中克隆出的去整合素adinbitor是含73个氨基酸残基的去整合素,分子中含有12个半胱氨酸和RGD模体.实验证明,adinbitor作为去整合素的新成员,具有典型的抗ADP诱导的人血小板聚集作用和抗肿瘤血管新生作用.为了将adinbitor的这2种功能分开,采用PCR基因定点突变的方法,将其cDNA序列中RGD模体改变成KGD.重组adinbitor(KGD)在E.coli BL21得到表达,并通过His•Bind亲和层析予以纯化.实验发现,adinbitor对ADP诱导的人血小板聚集具有明显抑制作用,其IC50=85 nmol/L,明显优于adinbitor(RGD) （IC50=150 nmol/L）.然而,与adinbitor(KGD)相比,adinbitor(KGD)则丧失了对血管生成的抑制作用.结果说明,adinbitor(KGD)可作为专一的抗人血小板聚集药具有潜在的开发前景.     

浙江产蝮蛇蛇毒对血小板聚集的影响

浙江产蝮蛇蛇毒的分离参照涂光俦(1979)的方法。浙江产蝮蛇蛇毒经DEAE-Sephadex A-50柱层析分离后得到14个蛋白峰,各峰的蛋白含量见表1。将收集的各峰经适当稀释后取0.2ml进行酶活力测定,除磷脂A酶活力按吴新陆、陈远聪(1981)方法测定外,其他酶活力测定如前文(云南省动物研究所,1976),然后做各峰对血小板聚集功能的影响,参照阮长耿等(1983)的方法,所用诱导剂的浓度为ADP(2μM),AA(100μg/ml)以及PAF(3×10~(-7)M),用这三种诱导剂诱导键康人对血小板产生不可逆性聚集,聚集强度分别为75％,75％和70％。粗毒在最终浓度为250μg/ml时能完全抑制上述三种诱导剂所致的血小板聚集。     

四种圆斑蝰蛇蛇毒对血小板聚集抑制作用的比较研究

对四种不同来源的RVV对ADP、Col和Ris诱导的血小板聚集抑制作用进行比较研究。RVV-B,RVVS和RVV-Styp对三种诱导剂的血小板聚集均有抑制作用,而RVV-T虽有ADP和Col抑制作用,但缺乏对Ris的抑制活性。预先与RVV孵育的血小板经洗涤后重新悬浮于自身PPP中,与RVV-StyP孵育的血小板完全恢复对Ris的凝集反应,而与RVV-B和RVV-S孵育的血小板仅部分恢复其反应。上述结果表明,在RVV中可能含有二种不同的血小板聚集抑制活性,而其抑制机理可能牵涉到血小板、血浆等因素。     

蛇毒神经生长因子的研究进展

神经生长因子（Ｎｅｒｖｅｇｒｏｗｔｈｆａｃｔｏｒ,ＮＧＦ）是神经系统最重要的生物活性分子之一,是交感神经元和感觉神经元生长和存活所必需的一种营养成分,对神经元的存活,神经纤维的生长和分化以及再生起极其重要的作用。它的有关研究已成为发育神经学、神经损伤...     

广东眼镜王蛇毒酸性磷脂酶A2的分离纯化及抗血小板聚集作用

目的 研究眼镜王蛇毒中酸性磷酸脂酶Ａ２对血小板的作用。方法 采用ＣＭ－Ｓｅｐｈａｄｅｓｘ Ｃ－２５Ｓｅｐｈａｄｅｘ Ｇ－７５,ＤＥＡＥ－Ｓｅｐ「ｈａｄｅｘＡ－２５,Ｓｅｐｈａｄｅｘ Ｇ－７５多步柱层析法,聚丙烯酰胺产胶电泳,酸性磷脂酶Ａ２酶活性测定;血小板聚集实验。累进要从粗中分离纯化出一酸性磷脂酶Ａ２单体,分子量为１４ＫＤ;等电点ＰＩ３．８;ＰＬＡ２比值２０μｍｏｌ．ｍｇ＾－１．ｍｉｎ＾－１;小     

长白山白眉蝮蛇蛇毒酸性PLA_2质谱鉴定及其对血小板聚集的抑制作用

通过对纯化得到的长白山白眉蝮蛇蛇毒磷脂酶A2（ABUSV-PLA2）进行胶内胰蛋白酶酶解,产生的肽段经高效液相色谱-电喷雾串联质谱（HPLC-nESI-MS/MS）进行序列测定,蛋白鉴定采用SequestBioworks软件完成。ABUSV-PLA2与其它蛇毒来源PLA2的氨基酸序列比对表明：ABUSV-PLA2是一种新的蛇毒酸性磷脂酶A2。以ADP诱导的人血小板聚集实验结果表明：ABUSV-PLA2对ADP诱导的血小板聚集有轻微的解凝效应,但具有显著拮抗血小板的聚集作用,并呈现明显的剂量-效应关系,IC50为356nmol/L。     

蛇毒酶治疗心脑血管病的概述

蛇毒中含有十多种酶类及其它蛋白,其中蛇毒中的凝血酶样酶具有降解血浆纤维蛋白原,降低血浆粘度,降低血小板聚集等作用。经分离纯化的蛇毒酶制剂,在临床上广泛使用已20多年,积累了丰富的经验。现将蛇毒酶在心脑血管病中的应用情况概述如下。     

Effects of Jarastatin, a Novel Snake Venom Disintegrin, on Neutrophil Migration and Actin Cytoskeleton Dynamics

A new disintegrin, an RGD-containing peptide of 6 kDa called jarastatin, was purified from Bothrops jararaca venom. It is a potent inhibitor of platelet aggregation induced by ADP, collagen, and thrombin. The effect of jarastatin on neutrophil migration in vivo and in vitro and on the actin cytoskeleton dynamics of these cells was investigated. Incubation in vitro with jarastatin significantly inhibited, in a concentration-dependent manner, the chemotaxis of human neutrophils toward fMLP, IL-8, and jarastatin itself. Despite this inhibitory effect, jarastatin induced neutrophil chemotaxis. A significant increase of F-actin content was observed in jarastatin-treated neutrophils. Furthermore, as demonstrated by confocal microscopy after FITC-phalloidin labeling, these cells accumulated F-actin at the plasmalemma, a distribution similar to that observed in fMLP-stimulated cells. Pretreatment of mice with jarastatin inhibited neutrophil migration into peritoneal cavities induced by carrageenan injection. The results suggest that binding of jarastatin to neutrophil integrins promotes cellular activation and triggers a dynamic alteration of the actin filament system and that this is one of the first event in integrin-mediated signaling.     

蛇毒与细胞凋亡

简要介绍了细胞凋亡的形态学变化和生物化学等特性,及其主要的定性、定量检测方法,综述了蛇毒在细胞凋亡和肿瘤研究中的发展概况和国外最新进展。     

Studies on Habu Snake Venom

It has been found that there are two factors responsible for myolysis in Habu snake venom; heat-labile and heat-stable myolytic factors. As reported previously, the former is a proteinase contained in Habu venom. In this article purification and chemical properties of the heat-stable myolytic factor are presented. Using the method of fractionation with ammonium sulfate and with column chromatography, a heat-stable myolytic factor was obtained ultracentrifugally in a homogeneous state. This factor caused severe myolysis with the aid of both Mg⁺⁺ ion and phospholipase A. It has been found that heat-stable myolytic factor has no activities such as those of proteinase, esterase or ribonuclease. The relationship between the heat-stable myolytic factor and phospholipase A in myolytic activity is discussed.     

Mitogenic Activity of Snake Venom Lectins

Abstract. Five lactose-inhibitable lectins have been isolated from snake venoms. These five share certain biochemical properties but are not identical (Gartner, Stocker & Williams, 1980; Gartner & Ogilvie, 1984). In this study the lectins were tested for their ability to stimulate lymphocytes to undergo DNA synthesis. We found that three of the lectins were comparable in mitogenic activity to the T cell lectin, concanavalin A (Con A). the mitogenic activity was blocked by lactose, a sugar which also blocks the haemagglutination activity of these lectins. Although mitogenic response appeared to be due to T cells, it depended on the presence of accessory cells in the culture. This requirement for macrophages could be replaced by the phorbol ester tumour promoter, 12- o -tetradecanoylphorbol-13-acetate (TPA).     

Thrombolytic Effects of the Snake Venom Disintegrin Saxatilin Determined by Novel Assessment Methods: A FeCl3-Induced Thrombosis Model in Mice

Saxatilin, a novel disintegrin purified and cloned from the venom of the Korean snake Gloydius saxatilis, strongly inhibits activation and aggregation of platelets. Glycoprotein (GP) IIb/IIIa receptor antagonists can resolve thrombus, so saxatilin might also have thrombolytic effects. We investigated the thrombolytic effects of saxatilin in mice using a ferric chloride-induced carotid arterial thrombosis model. Thrombotic occlusion and thrombus resolution were evaluated quantitatively by measuring blood flow in the carotid artery with an ultrasonic flow meter and calculating the degree of flow restoration on a minute-by-minute basis; results were confirmed by histological examination. Saxatilin dissolved thrombi in a dose-dependent manner. Saxatilin at 5 mg/kg restored blood flow to baseline levels. As saxatilin dose increased, time to recanalization decreased. A bolus injection of 10% of a complete dose with continuous infusion of the remaining dose for 60 minutes resulted in effective recanalization without reocclusion. The thrombolytic effect of saxatilin was also demonstrated in vitro using platelet aggregometry by administering saxatilin in preformed thrombi. Bleeding complications were observed in 2 of 71 mice that received saxatilin. Fibrin/fibrinogen zymography and platelet aggregometry studies indicated that saxatilin does not have fibrinolytic activity, but exerted its action on platelets. Integrin-binding assays showed that saxatilin inhibited multiple integrins, specifically α_2bβ₃ (GP IIb/IIIa), α₅β₁, α_vβ₃, α_vβ₁, and α_vβ₅, which act on platelet adhesion/aggregation. Saxatilin inhibited multiple integrins by acting on platelets, and was safe and effective in resolving thrombi in mice.     

蛇毒类凝血酶的研究进展

已在40余种蛇毒中发现类凝血酶成份,其有效的体内抗凝、体外促凝作用逐渐受到关注.对它的性质结构及制备纯化的研究取得重要成果.在揭示酶的功能与结构关系以及临床抗血栓应用方面前景广阔.     

蛇毒的采集与利用

蛇毒是毒蛇头部两侧皮肤下方毒腺的分泌物,在咬啮物体时从毒牙流出,是含多种活性酶的蛋白质。蛇毒虽能伤害人畜,但若能善加利用,可化害为利而成为良药。此外,还可从中提取许多难得的成分作为现代科学研究之用。因而,被誉为“液体黄金”的蛇毒,具有极高的经济价值。现将蛇毒的采集和利用概述如下。