蕲蛇蛇毒中一种新型自降解抗凝血酶AA-ACA-I的纯化和表征

利用嗜硫色谱和POROS HQ20离子交换色谱从蕲蛇蛇毒中纯化得到一种新型P-Ⅲ型蛇毒金属蛋白酶（snake venom metalloproteases SVMP) AA-ACA-I.该酶经SDS-PAGE测得分子量为 47.6 kD,含有链内二硫键,加DTT处理后,分子量为50.8 kD,中性糖含量为3.5%,具有出血毒性和抗凝血活性.在70℃和pH 9.0条件下保温60 min,该酶会自降解成分子量30 kD左右的新蛋白,降解得到的新蛋白抗凝血活性高于原蛋白     

榆黄蘑中一种抗病毒蛋白的纯化及其抗TMV和HBV的活性

采用阴离子交换层析和凝胶层析方法从新鲜食用菌榆黄蘑 (Plearotuscitrinopileatus)中进行了抗病毒蛋白的纯化 ,结果获得了一个纯化蛋白YP4 6 4 6 ,经SDS PAGE可确定其分子量为 2 7.4kD。以半叶法在枯斑寄主心叶烟上检测该蛋白对烟草花叶病毒 (TMV)的抑制率 ,发现有较好的抗TMV活性 ,其抑制TMV的中浓度为 0 .2 4 μg/mL。同时以HepG2 .2 .2 .15细胞株为模型 ,对所获得的蛋白进行体外抗乙型肝炎病毒效果的评价。结果表明该蛋白对HBsAg的 5 0 %抑制时的浓度为 0 .0 8μg/mL ,但对HBeAg效果不大     

尖吻蝮蛇毒内一种新的抗血小板凝集蛋白agkisacutacin的纯化及其性质

从皖南尖吻蝮蛇毒中经阴离子交换层析和凝胶过滤层析分离纯化得到抗血小板凝集蛋白agkisacutacin ,纯化的agkisacutacin由分子量为 1 4kD和 1 5kD的 2条肽链通过二硫键连接 ,能有效抑制ristocetin诱导的血小板凝集 (IC5 0 为 1 8.5mg/L) ,能轻微抑制凝血酶诱导的血小板聚集 (IC5 0 为 1 .2 2 g/L) ,但对ADP、胶原诱导的血小板聚集无影响。agkisacutacin不具有纤溶活性、抗凝活性、磷脂酶A2 活性和出血活性 ,是一种潜在的安全、有效的抗血小板性栓塞的药物     

菜花烙铁头蛇毒中一种具有激肽释放酶与纤维蛋白原溶酶活性的Jerdonase

通过DEAESephadexA 5 0阴离子交换、超细SephadexG 10 0分子筛和反相高效液相C4 色谱层析 ,从菜花烙铁头蛇毒冻干粉中纯化出一种具有激肽释放酶活性和α纤维蛋白原溶酶活性的丝氨酸蛋白酶 ,命名为Jerdonase。在 12 .5 %胶浓度的SDS还原电泳条件下 ,该酶分子量大约为 5 5kD ,在非还原电泳条件下 ,分子量大约为 5 3kD。此酶是一种糖蛋白 ,含有约 35 .8%的中性糖。它的N末端氨基酸序列为IIGGDEENINEHPFLVALYDA ,其序列和蛇毒中其他丝氨酸蛋白酶具有非常高的序列相似性。Jerdonase能够催化BAEE、S 2 2 38和S 2 30 2的水解 ,其水解活性可被PMSF抑制 ,但是EDTA对此没有影响。Jerdonase能优先水解人纤维蛋白原的Aα链 ,同时伴随有微弱的Bβ链水解活性。另外 ,此酶能够水解牛低分子量的激肽原 ,释放舒缓激肽。总之 ,所有的结果表明Jerdonase是一个具有多功能活性的蛇毒丝氨酸蛋白酶     

大鼠脂多糖结合蛋白的分离纯化及对脂多糖的调节作用

经硫酸铵沉淀、Bio Rex70树脂的阳离子交换层析和MonoQ预装柱的阴离子交换层析 ,从大鼠急性期血清中分离纯化了脂多糖结合蛋白 .SDS PAGE为单一条带 ,分子量 60kD ,所纯化的大鼠脂多糖结合蛋白可明显增强脂多糖与单核巨噬细胞的结合 .脂多糖结合蛋白对脂多糖诱导肺泡巨噬细胞中肿瘤坏死因子α(TNF α)mRNA表达的调节作用具有明显的剂量依赖性 .     

一个高活性的盂加拉眼镜蛇毒抗补体因子

用离子交换层析和分子筛从云南南部产的盂加拉眼镜蛇（Naja kaouthia)蛇毒中分离到一个高活性的抗补体因子（anticomplement factor)。它表现出较强的体内、体外抗补体活性,其抗补体活性的比活力为1515u/mg,纯化的抗补体因子在聚丙烯酰胺凝胶电泳中呈现一条带,经SDS-PAGE,确定其全分子量为149kD,还原性SDS-PAGE表明,它由3条多肽链共价结合而成,3条多肽链分子量分别为65.4kD、52.1kD和35.5kD。最小的一条多肽链在还原条件下呈现多态性,一般可见两条带（35.5kD和33.7kD)。过碘酸席夫试剂染色表明,其3条多肽链均含有糖。定量测定表明中性糖含量为1.78%,唾液酸含量为0.38%,其等电点为6.2。对其氨基酸组成分析表明它含有较多的酸性氨基酸,对其3条多肽链的N末端氨基酸序列进行了测定。     

东北白眉蝮蛇毒类凝血酶的分离纯化

我国多年来因技术原因 ,一直使用多组份混合成分的蛇毒制剂 ,临床上虽有一定疗效 ,但存在严重的副作用。作者利用细胞融合技术成功地建立了一株高表达类凝血酶抗体的细胞系 ,该抗体经纯化后 ,可高效亲和白眉蝮蛇类凝血酶。该技术使纯化蛇毒类凝血酶工艺有了很大的飞跃 ,也使蛇毒制品质量达到世界先进水平。方法 :采用天然蛇毒经 DEAE-琼脂糖凝胶层析 ,收集活性组份 ,再经葡聚糖凝胶 G- 75柱层析后 ,收集活性组份 ,最后经类凝血酶亲和柱层析 ,测定 2 80 nm的光吸收度 ,收集蛋白峰 ,测定活性 ,获得了单一组份的类凝血酶 ,即为纯化的类凝血酶…     

N-氨甲酰基-D-氨基酸酰胺水解酶的快速纯化及性质

通过硫酸铵分级沉淀、疏水层析及阴离子交换层析等三步 ,有效地从一菌株NO .2 2 6 2中纯化了N 氨甲酰基 D 氨基酸酰胺水解酶。结果表明 ,酶活性回收约 2 0 %,纯化了 8 4倍。天然PAGE与SDS PAGE分析表明 ,该酶分子为同源四聚体 ,单体分子量约为 3 5kD。酶催化反应的最适pH为 7 7～ 8 0 ,最适温度为 45℃。以N 氨甲酰 DL 丙氨酸为底物时 ,Km =1 3×1 0 - 3 mol L ,Vmax=0 .3 3mol min。二价金属离子Ni2 + 有激活作用 ,Zn2 + 有明显的抑制作用 ,而Co2 + 对酶活无影响。该酶N 末端 8个氨基酸残基依次为TRQKILAF。     

烙铁头蛇毒L—氨基酸氧化酶的分离、纯化及其生物学活性

通过DEAESephadexA 5 0阴离子交换柱 ,SephadexG 75分子筛 ,ResourseQ阴离子交换柱三步层析从湖南产的烙铁头蛇毒中分离、纯化得到一个L 氨基酸氧化酶 (TM LAO) ,它由两个非共价的亚基组成 ,每个亚基的分子量为 5 5kD。与台湾产的烙铁头蛇毒L 氨基酸氧化酶分子量 ( 70kD)不同。TM LAO的N末端氨基酸序列是ADNKNPLEECFRETNYEEFLEIAR ,与报道的蝰科的L 氨基酸氧化酶的相似性比眼镜蛇科的要高。TM LAO能抑制大肠杆菌、金黄色葡萄球菌和痢疾杆菌的生长 ,杀死肿瘤细胞以及诱导血小板聚集。这些活性能被过氧化氢酶所抑制 ,说明TM LAO生理学功能主要是通过酶反应产生的过氧化氢 (H2 O2 )介导的     

N-氨甲酰基-D-氨基酸酰胺水解酶的快速纯化及性质

通过硫酸铵分级沉淀、疏水层析及阴离子交换层析等三步 ,有效地从一菌株NO .2 2 6 2中纯化了N 氨甲酰基 D 氨基酸酰胺水解酶。结果表明 ,酶活性回收约 2 0 %,纯化了 8 4倍。天然PAGE与SDS PAGE分析表明 ,该酶分子为同源四聚体 ,单体分子量约为 3 5kD。酶催化反应的最适pH为 7 7～ 8 0 ,最适温度为 45℃。以N 氨甲酰 DL 丙氨酸为底物时 ,Km =1 3×1 0 - 3 mol L ,Vmax=0 .3 3mol min。二价金属离子Ni2 + 有激活作用 ,Zn2 + 有明显的抑制作用 ,而Co2 + 对酶活无影响。该酶N 末端 8个氨基酸残基依次为TRQKILAF。     

尖吻蝮蛇毒内一种新抗凝血因子ACF II 的纯化及特性

利用阴离子交换层析、凝胶过滤及阳离子交换层析三步方法, 从皖南尖吻蝮蛇毒中分离纯化到一个新的抗凝血因子ＡＣＦＩＩ（ａｎｔｉｃｏａｇｕｌａｔｉｏｎ ｆａｃｔｏｒＩＩ） 。纯化的ＡＣＦＩＩ在ＰＡＧＥ、ＳＤＳＰＡＧＥ和ＩＥＦＰＡＧＥ图谱上均呈单一区带。ＡＣＦＩＩ由两条分子量为１４．６ ｋＤ 的肽链通过二硫键连接在一起, 其等电点为７．０。ＡＣＦＩＩ具有显著的抗凝血活性, 在体外延长ＰＰＴ 时间的最终浓度为０ ．４ ｍｇ／Ｌ。ＡＣＦＩＩ不具有类凝血酶活性、磷脂酶Ａ２ 活性和纤溶活性,也没有出血活性和毒性, 是一种潜在的高效抗凝药物。     

五步蛇蛇毒磷脂酶A_2的纯化及部分性质

经Sephadex G-75和QAE-Sephadex A-50离子交换层析等方法,从湖南产五步蛇(Agkistrodon acutus)蛇毒中纯化一种均一的酸性磷脂酶A_2。SDS-PAGE测得分子量为15.8kD,按氨基酸残基计算其分子量为14.352kD,IEF-PAGE测得等电点为5.32。氨基酸组份分析表明磷脂酶A_2分子由128个氨基酸残基组成,富含Asp和Glu,不含中性糖。PLA_2酶活性的最适温度为45℃,最适pH为8.5左右,没有抗胰蛋白酶的活性,具一定的热稳定性。K~+、Ca~(++)和Na~+离子激活,而Cd~(++)、Sn~(++)、Cu~(++)、Li~+、Hg(++)、Zn~(++)、Fe~(++)和Co~(++)离子可抑制或完全丧失酶活力。手工微量顺序分析测得PLA_2分子N-末端氨基酸为Leu。此酶对小白鼠的LD_(50)至少大于10mg/kg(ip)。     

皖南尖吻蝮蛇毒出血毒素Ⅳ的纯化与初步鉴定

从皖南尖吻蝮蛇（Ａｇｋｉｓｔｒｏｄｏｎａｃｕｔｕｓ）毒液中经ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ和ＳｅｐｈａｃｒｙｌＳ－２００两步凝胶柱层析首次纯化出一种中分子量出血毒素（简称ＡａＨⅣ）．经ＳＤＳ－ＰＡＧＥ和等电聚焦凝胶电泳测定其分子量为４４ｋＤ,等电点为ｐＨ５．０．从５００ｍｇ粗毒中可获得２０ｍｇＡａＨⅣ纯品．ＡａＨⅣ有较强的出血活性,最小出血剂量（ＭＨＤ）为０．４μｇ．     

乌梢蛇血清的抗出血因子:一个有前途的抗蛇毒药物原料

用柱层析和聚丙烯酰胺凝胶盘状电泳法,从乌梢蛇血清中分离纯化了一个抗出血因子。用SDS-聚丙烯酰胺凝胶电泳法测得其分子量大约为65 kD;测定了五种蝮亚科蛇毒(尖吻蝮、竹叶青蛇、原矛头蝮、哈扑和短尾蝮)的最小出血剂量和乌梢蛇血清中抗出血因子对这五种蛇毒的抗出血活性;还测定了七种蛇毒(除上述五种毒蛇外,还包括圆斑蝰和银环蛇)的半数致死量,以及抗出血因子对中毒小鼠的治疗作用。结果显示:从乌梢蛇血清中提纯的抗出血因子的抗蛇毒活性,不仅可以抵抗它的捕食者尖吻蝮的蛇毒,而且还可以抵抗具出血活性的其它蛇毒;但它对不具出血活性的银环蛇毒的致死抑制作用不明显。该抗出血因子不仅在体外实验表现出强的中和出血毒素的活性,而且在体内实验中亦表现出对中毒小鼠良好的治疗作用,因而可能成为新的抗蛇毒药物的有前途的原料。乌梢蛇血清对血循毒的中和能力的获得,可能归因于尖吻蝮与乌梢蛇之间捕食与被捕食相互作用的关系。     

Purification and characterization of an anticoagulant from the salivary glands of the ixodid tick Rhipicephalus appendiculatus

An anticoagulant isolated from salivary gland extracts of the ixodid tick Rhipicephalus appendiculatus was purified by gel filtration on Sephadex G-100, ion exchange on DEAE-cellulose, aprotinin-Sepharose, and by high-pressure-liquid size-exclusion chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the anticoagulant activity was associated with a protein of an apparent Mr of 65 kDa. The purified molecule had a pI in the range of 8.0-8.5 on chromatofocusing and was stable over a wide pH range, but was heat labile and susceptible to inactivation by trypsin and reductive alkylation. The anticoagulant did not inhibit thrombin-initiated fibrin formation and had no detectable fibrino(geno)lytic or phospholipase-like activities. Although it inhibited factor Xa-induced clotting of bovine plasma, it did not affect the amidase activity of factor Xa toward a synthetic substrate, suggesting that the anticoagulant acts at a site distinct from the active site of factor Xa or on other components of the prothrombinase complex.     

Purification and properties of the anticoagulant principle of Trimeresurus gramineus venom.

By means of DEAE-Sephadex A-50 column chromatography, Trimeresurus gramineus venom was separated into 12 fractions. Fraction 8 had marked anticoagulant action in the tests of whole blood clotting time, calcium clotting time and plasma prothrombin time. Fraction 8 was rechromatographed on Sephadex G-100, then on DEAE-Sephadex A-50 again, and finally on Sephadex G-100, and a single peak was obtained. The patterns of microzone and disc electrophoresis also showed a single band. A single symmetrical boundary with 1.70 Svedberg units was obtained by ultracentrifugation. The estimated molecular weight was 19 500. The isoelectric point was pH 4.5. Chemical analysis showed that the anticoagulant principle was a glycoprotein and that it was thermolabile. The anticoagulant activity of this purified principle was 3.5 times higher than that of the crude venom. Fraction 5 potentiated its anticoagulant activity to 10 times higher than that of the crude venom. This principle did not possess caseinolytic, tosyl-L-arginine methyl ester esterase, phospholipase A, phosphodiesterase, alkaline phosphomonoesterase, fibrinolytic, hemorrhagic or local irritating activities. The purified anticoagulant principle did not destroy fibrinogen, induce fibrinolysis, inactivate thrombin nor interfere with the interaction between thrombin and fibrinogen. However, a marked inhibition of prothrombin activation was caused by the anticoagulant principle. The inhibition of prothrombin activation was not due to the destruction of prothrombin or its activation factors, but due to an interference in the interaction between prothrombin and its activation factors because of the reversible binding of these factors with the anticoagulant principle of the venom.     

Affinity chromatography in the separation of human alpha 1-antitrypsin (alpha 1-AT) and antithrombin-III (AT-III).

The two antiproteases alpha 1-antitrypsin (alpha 1-AT) and antithrombin-III (AT-III) have been purified simultaneously from human plasma. Purification procedure consisted of gel filtration on Sephadex G-200 after initial processing of plasma, followed by ion exchange chromatography on DEAE-Sephadex A50 and DEAE-Cellulose, at a pH of 9.0 and pH 8.3 respectively. The two proteins could not be separated by any of these procedures including a lower pH (7.4) in ion exchange chromatography. Affinity chromatography on heparin-Sepharose separated the proteins since alpha 1-AT did not bind to the matrix. Alpha 1-AT unbound to the heparin-Sepharose was subsequently purified through con A-Sepharose affinity column. The final yield of both the proteins was about 20%. The molecular weight estimated on SDS electrophoresis for AT-III and alpha 1-AT was 63,000 and 50,000, respectively.     

A novel blood coagulation factor IX/factor X-binding protein with anticoagulant activity from the venom of Trimeresurus flavoviridis (Habu snake): isolation and characterization

Using affinity chromatography on a column of factor X-Cellulofine, we have isolated a novel blood coagulation factor X-binding protein with anticoagulant activity from the venom of Trimeresurus flavoviridis (Habu snake). This anticoagulant protein was also purified by chromatography on Sephadex G-75 and S-Sepharose Fast Flow. The yield of the purified protein was approximately 16 mg from 400 mg of crude venom. The purified protein gave a single band on both analytical alkaline disc-gel electrophoresis and SDS-PAGE. This protein had a relative molecular weight (Mr) after SDS-PAGE of 27,000 before reduction of disulfide bonds and 14,000 after reduction of disulfide bonds. The protein prolonged the clotting time induced by kaolin or factor Xa. In the presence of Ca2+, it formed a complex with factor X, the molar ratio being 1 to 1. Similar complex formation was observed with factor Xa and factor IX/factor IXa, but not with other vitamin K-dependent coagulation factors, i.e., prothrombin, factor VII, protein C, protein S, and protein Z. The interaction of this anticoagulant protein with factor IX/factor X was dependent on gamma-carboxyglutamic acid (Gla) domains, since Gla-domainless derivatives of factor X and factor IXa beta' did not interact with this anticoagulant protein.