ELISA法测定蛇毒降纤酶水溶液的稳定性

考察了蛇毒降纤酶在不同pH缓冲液的稳定性。以酶联免疫吸附法(ELISA)测定了蛇毒降纤酶的抗原活性稳定性,并与凝固时间法测定的生物活性稳定性进行了比较。降纤酶抗原活性与其生物活性随时间降低的趋势一致(pH 3.6的缓冲液除外)。较高浓度的降纤酶在中性pH 6~7的缓冲液中比较稳定,40oC 放置10天后,仍能保持其原有活性(100BUmL-1) 的95% 以上。而较低浓度的降纤酶(5BUmL-1)水溶液相对不稳定,尤其在酸性(pH 3.6)或碱性(pH 9)条件下很容易失去活性。加入Triton X-100或牛血清白蛋白,由于降低了表面吸附,可显著提高降纤酶水溶液的稳定性(P<0.005)。     

黄芩苷完全抗原的合成鉴定及其多克隆抗体的制备

目的:研究黄芩苷作为一种半抗原分子,通过与载体蛋白偶联形成完全抗原后,使免疫动物血清中产生特异性抗体的可能性,为进一步建立黄芩苷的免疫分析测定方法提供实验依据。方法:采用活性酯法将黄芩苷(BAL)与牛血清白蛋白(BSA)偶联,制备黄芩苷完全抗原(BAL-BSA),并采用红外吸收光谱法、SDS-PAGE法、MALDI-TOF-MS法对其进行鉴定。用此完全抗原免疫动物制备抗血清,通过间接ELISA法检测其抗体效价。结果:完全抗原BAL-BSA中BAL与BSA的偶联比为3∶1;用此完全抗原免疫的家兔产生针对BAL的多克隆抗体,抗体效价最高可达1∶8000。结论:成功合成了BAL的完全抗原BAL-BSA,且该抗原具有良好的反应原性与免疫原性。     

长白山白眉蝮蛇蛇毒中类凝血酶的分离纯化方法研究

目的:研究长白山白眉蝮蛇蛇毒中类凝血酶的简单分离纯化方法。方法:采用DEAE-Sephadex A-25及Sephadex G-25层析的方法,比较二者对长白山白眉蝮蛇蛇毒中类凝血酶简单分离纯化的效果。结果:从长白山白眉蝮蛇蛇毒中分离出类凝血酶,SDS-PAGE电泳显示为一条带,分子量大约为35.5kDa,达到电泳纯。理化性质研究表明,此类凝血酶具有体外凝血活性,体外凝血酶比活力为12.57IU.mg-1,用N-苯甲酰-L-精氨酸乙酯盐酸盐测得该酶的精氨酸酯酶比活力为137.65IU.mg-1。用蛋白酶抑制剂和乙二胺四乙酸对该酶进行抑制实验,结果表明该酶属于丝氨酸蛋白酶,而不是金属蛋白酶。结论:本方法可用于长白山白眉蝮蛇蛇毒中类凝血酶的分离纯化。     

Ⅳ型胶原多克隆抗体的制备及性质研究

目的通过免疫母鸡制备抗人Ⅳ型胶原多克隆抗体（IgY）,为检测人血清Ⅳ型胶原含量提供IgY。方法采用人胎盘来源的Ⅳ型胶原蛋白作为抗原,免疫Leghorn母鸡,采用PEG方法分离纯化鸡卵黄中的抗体,获得抗体粗提物。经SephadexG100凝胶过滤制备多克隆抗体纯品。使用SDS—PAGE、免疫琼脂双向扩散等方法对提取物的含量、纯度及特异性进行鉴定。结果电泳结果显示,抗体粗提物纯度为81％。抗体纯品仅在70kd和25kd处各有一条带,纯度达到96％;免疫琼脂双向扩散实验结果显示,抗体纯品、粗品及免疫三周后鸡血清均与中心孔的抗原形成抗原抗体复合物的乳白色沉淀线。结论本研究分离纯化方法制备的抗Ⅳ型胶原IgY,具有抗体纯度高、特异性强等特点,为多克隆抗体广泛应用奠定了基础。     

长白山白眉蝮蛇血凝酶的分离纯化研究

摘 要 目的：建立一种分离纯化长白山白眉蝮蛇血凝酶的方法。方法: 先后采用分子筛层析法、离子交换色谱法、肝素 Sepharose亲和层析法从长白山白眉蝮蛇蛇毒中分离纯化得到一种具有有凝血活性的酶成分,并采用SDS-Page法、RP-HPLC法测定其纯度,凝胶电泳法(SDS-Page)考察其对牛纤维蛋白原的作用方式、高效空间排阻色谱法（HPSEC）测定其相对分子质量,等电聚焦电泳分析法（IEF）测定其等电点,Lowry法测定其蛋白浓度。结果: 从长白山白眉蝮蛇蛇毒中分离纯化了一种凝血酶成分,SDS-Page显示为一条带,HPLC得到单一的色谱峰,该酶只作用于纤维蛋白原的α链,其相对分子质量为32.2 kD,等电点为5.21,此酶具有体外凝血活性。结论:该方法可用于长白山白眉蝮蛇血凝酶的分离纯化。     

卵黄抗体用于蛇毒抗原检测的初步研究

目的在常规ELISA检测中,以卵黄抗体取代哺乳动物来源的IgG类抗体,以探讨卵黄抗体应用于蛇毒检测的可行性。方法以甲醛减毒的眼镜王蛇毒抗原免疫莱航母鸡,制备抗眼镜王蛇毒抗体;采用过碘酸钠法对特异卵黄抗体进行酶标;将卵黄抗体及相应酶标抗体应用于常规ELISA中,对国内常见蛇毒样品抗原(包括眼镜王蛇毒、眼镜蛇毒、金环蛇毒、银环蛇毒、五步蛇毒及广东园斑蝰蛇毒)进行检测,并进行灵敏度、精确度、特异性及交叉反应等分析。结果检测的灵敏度可达32μg.L-1,并且眼镜王蛇毒抗原浓度在32~750μg.L-1的范围内,线性关系较好(r=0.963);初步应用表明卵黄抗体对眼镜王蛇毒具有较高的特异性,与蝰蛇科的五步蛇毒、园斑蝰蛇毒无交叉反应,与眼镜蛇科的金环及银环蛇毒仅在高剂量(剂量大于500μg.L-1)时存在轻度交叉反应,不干扰实验检测,但与眼镜蛇毒之间交叉反应明显,干扰实验检测;应用本方法对低(100μg.L-1)、中(300μg.L-1)、高(1 000μg.L-1)不同浓度的眼镜王蛇毒样品检测,结果平均板内变异系数均在1%~3%之内,板间变异系数在8%以内。结论特异的卵黄抗体应用于微量蛇毒检测研究是可行的,具有灵敏度高、特异性较强等优点。该研究将为蛇伤诊断试剂盒的研制提供相应的理论依据。     

鸡卵黄多克隆抗体IgY的研究进展

鸡卵黄免疫球蛋Ｙ（ＩｇＹ）因其具有一些特殊的生物学性质，近年来已逐渐被人们所重视本文就鸡抗体应答、ＩｇＹ的物理化学及生物学特性、分离纯化方法以及ＩｇＹ的基础研究及疾病诊断、预防和治疗中的应用作一概述。     

卵黄抗体用于眼镜王蛇毒抗原检测的初步研究

目的探讨抗蛇毒卵黄抗体应用于蛇毒检测的可行性。方法以甲醛减毒的眼镜王蛇毒抗原免疫莱航母鸡,制备抗眼镜王蛇毒抗体;采用过碘酸钠法对特异卵黄抗体进行酶标;ELISA的实验条件及相关参数通过棋盘滴定法确定,并进行特异性、灵敏度、精确度及稳定性等测定。结果本检测方法的灵敏度可达32μg·L-1,并且眼镜王蛇毒抗原浓度在32～750μg·L-1的范围内,线性关系较好(r=0.963);卵黄抗体对眼镜王蛇毒具有较高的特异性,与蝰蛇科的五步蛇毒、园斑蝰蛇毒无交叉反应,与眼镜蛇科的金环及银环蛇毒仅在高剂量(剂量大于500μg·L-1)时存在轻度交叉反应,但与眼镜蛇毒之间交叉反应明显。应用本方法对不同浓度(100、300、1000μg·L-1)的眼镜王蛇毒样品检测,结果平均板内相对标准差在1%～3%之内,板间相对标准差在8%以内;稳定性实验显示:卵黄抗体置于37℃条件6天,其检测结果与4℃条件下无显著差异(P>0.05)。结论特异的卵黄抗体应用于微量蛇毒检测研究是可行的,但仍需要进一步研究以降低交叉反应。     

3个重要酶的多克隆抗体的制备条件优化

目的制备优质的抗几丁质酶、α-甘露糖苷酶、谷胱甘肽转硫酶的多克隆抗体。方法利用纯化的不同免疫剂量的3种酶分别免疫不同兔龄的新西兰兔。结果使用0.3mg纯化蛋白、免疫6月龄的新西兰兔所制备出的抗体效价高、特异性好。结论这一结果为今后规模化制备相关多克隆抗体奠定了坚实的实验基础。     

Pharmacokinetics of thrombin-like enzyme from venom of Agkistrodon halys ussuriensis Emelianov determined by ELISA in the rat.

A thrombin-like enzyme (TLE) was separated and purified from the venom of a northeast Chinese snake Agkistrodon halys ussuriensis Emelianov. Experiments were performed in rats to determine the pharmacokinetic parameters following an intravenous (i.v.) or a subcutaneous (s.c.) injection of the thrombin-like enzyme. The plasma levels of TLE were estimated by enzyme-linked immunosorbent assay. The method exhibited high reproducibility and accuracy in correlating optical densities with TLE concentrations (0.2–30 ng ml⁻¹, r=0.99). The plasma concentration-time course after i.v. administration of 50 μg kg⁻¹ TLE was well fitted by a two-compartment open model. The half-life of the -phase was 18.0±3.2 min, and that of the β-phase 3.9±0.7 h. The apparent volume of distribution was 1.8±0.5 l kg⁻¹, and clearance was 5.4±0.5 ml min⁻¹ kg⁻¹. When the TLE was injected s.c. at a dose of 0.75 mg kg⁻¹, the changes in plasma concentration were best described by a two-compartment model with a first-order absorption. The maximal plasma level of 51±2.7 ng ml⁻¹ was reached at 5.2±0.5 h. The absorption rate constant was 0.3±0.03 h⁻¹. The area under the plasma concentration-time curve (AUC) was 2.8±0.8 μg h⁻¹ ml⁻¹.     

白眉蝮蛇降纤酶的纯化及特性分析

目的从白眉蝮蛇蛇毒中提取降纤酶,并对其进行特性分析。方法采用一步亲和色谱法分离纯化降纤酶,用高效液相色谱分析其纯度,SDS-PAGE测定其相对分子质量。结果分离得到的降纤酶纯度高(99%以上),SDS-PAGE分析为一条带,相对分子质量为36 000,比活性为4 800 u/mg。结论用一步亲和色谱法从白眉蝮蛇蛇毒中纯化降纤酶的方法简单有效,所得产品纯度高、产量高。     

蝮蛇毒血小板抑制因子对动脉血栓形成的影响及机制研究

目的：探讨皖南蝮蛇毒血小板抑制因子（AHV-PI）对家兔动脉血栓形成的影响及可能机制。方法：新西兰家兔24只,随机分成假手术组、动脉血栓模型组、阳性对照组（奥扎格雷钠,5mg/kg）,AHV-PI（0.1mg/kg）实验组共4组,每组6只。应用70%FeCl3溶液化学损伤的方法来制备家兔颈动脉血栓模型,采用血栓弹力仪（TEG）描计血栓弹力图,比浊法测定家兔血小板聚集率,ELISA测定各组血浆中α颗粒膜蛋白（GMP-140）和血栓素B2（TXB2）水平,光镜和透射电镜分别观察动脉血栓形成和血小板形态的改变。结果：AHV-PI实验组与模型组相比,血栓弹力图凝血时间（R）值和血凝块形成时间（K）值延长（P〈0.01和P〈0.05）,Alpha角度、最大幅度（MA）和凝血指数（CI）减小（P〈0.05和P〈0.01）;血小板聚集率的各项指标均明显降低（P〈0.05）;血浆中GMP-140和TXB2含量降低（P〈0.01）。AHV-PI实验组光镜下动脉内未见血栓形成,血小板电镜显示血小板形态基本规则,与模型组相比伪足较少,α-颗粒和致密颗粒无明显减少,胞浆空泡化现象减轻。结论：AHV-PI可以通过抑制血小板聚集,防止动脉血栓的形成,其机制可能与之保护血小板超微结构,减少血小板脂质代谢和颗粒内容物的释放有关。     

江浙蝮蛇毒镇痛组分对吗啡依赖大鼠尾状核神经肽的调控作用

目的:研究江浙蝮蛇毒镇痛C4组分对大鼠尾状核中神经肽水平的调控作用.方法:应用微透析技术,探针定位于大鼠尾状体,以人工脑脊液透析,HPLC检测亮氨酸脑啡肽、β-内啡肽和P物质的含量,动态监测其变化.结果:在吗啡依赖大鼠给予C4组分后,尾状核亮氨酸脑啡肽含量显著增高,为可乐定组的1.5倍,并持续作用8h以上,而β-内啡肽和P物质含量变化较小.结论:C4组分主要作用于亮氨酸脑啡肽,通过提高其含量发挥镇痛作用.     

~(131)I标记尖吻蝮蛇毒凝血酶样酶在动物体内的分布

用氯胺T法对尖吻蝮(Agkistrodon acutus)蛇毒的抗血栓组分凝血酶样酶进行~(131)Ⅰ标记,观察其在大、小鼠体内的分布。以实验组和给予同剂量凝血酶样酶混合Na~(131)Ⅰ的对照组的放射性参入量(脏器与血液放射比)的比值作为凝血酶样酶在组织中分布的依据。结果表明,一次快速ⅳ凝血酶样酶后2h分布最多的为肾、其次为肺、脾、肾上腺和肝。给药后4h,肾、脾、肺和肝比2h时高,心脏含量较少,其它组织未见有分布。尿中含量高,表明其主要经肾脏随尿排泄;经胆汁排出则很少。     

Primary structure of a thrombin-like serine protease, kangshuanmei, from the venom of Agkistrodon halys brevicaudus stejneger.

The complete amino acid sequence of the thrombin-like serine protease, named kangshuanmei, isolated from the venom of a Chinese snake Agkistrodon halys brevicaudus stejneger, was determined by Edman degradation. The serine protease was composed of 236 amino acid residues and conserved the catalytic triad as His43, Asp88 and Ser182. The protease had four sites of asparagine-linked glycosylation at 81, 99, 148 and 229, and contained fucose, N-acetylglucosamin, galactose, mannose and N-acetylneuraminic acid. The amino acid sequence exhibited considerable similarities with other thrombin-like proteases isolated from the snake venoms of the Viperidae family. However, the enzymatic characteristics of kangshuanmei distinct from that of thrombin and the other protease from the venom of Viperidae family may be derived from the structural difference of the sequence in the functional regions, especially corresponding to thrombin exosite 1, 2 and hydrophobic pocket.     

Bioassay-directed purification of an acidic phospholipase A(2) from Agkistrodon halys pallas venom.

Relying on ex vivo and in vitro platelet anti-aggregation assays, a tail bleeding time assay, and an anti-thrombotic assay, we have purified the fraction of venom from Agkistrodon halys pallas which, in all of these assays, is the most active. There were two major steps in the purification: gel filtration chromatography on Sephadex G-100, and ion exchange chromatography on DEAE Sephadex A-50. Sequencing of the most active fraction by mass spectrometry revealed that it is a known acidic phospholipase A(2). Prior expectations by others about the in vivo anti-thrombotic activity of this enzyme are confirmed.     

Pharmacokinetics of thrombin-like enzyme from venom of Agkistrodon halys ussuriensis Emelianov determined by ELISA in the rat

A thrombin-like enzyme (TLE) was separated and purified from the venom of a northeast Chinese snake Agkistrodon halys ussuriensis Emelianov. Experiments were performed in rats to determine the pharmacokinetic parameters following an intravenous (i.v.) or a subcutaneous (s.c.) injection of the thrombin-like enzyme. The plasma levels of TLE were estimated by enzyme-linked immunosorbent assay. The method exhibited high reproducibility and accuracy in correlating optical densities with TLE concentrations (0.2–30 ng ml⁻¹, r=0.99). The plasma concentration-time course after i.v. administration of 50 μg kg⁻¹ TLE was well fitted by a two-compartment open model. The half-life of the α-phase was 18.0±3.2 min, and that of the β-phase 3.9±0.7 h. The apparent volume of distribution was 1.8±0.5 l kg⁻¹, and clearance was 5.4±0.5 ml min⁻¹ kg⁻¹. When the TLE was injected s.c. at a dose of 0.75 mg kg⁻¹, the changes in plasma concentration were best described by a two-compartment model with a first-order absorption. The maximal plasma level of 51±2.7 ng ml⁻¹ was reached at 5.2±0.5 h. The absorption rate constant was 0.3±0.03 h⁻¹. The area under the plasma concentration-time curve (AUC) was 2.8±0.8 μg h⁻¹ ml⁻¹.     

Purification and characterization of antitoxic proteins from the serum of Agkistrodon halys Pallas.

In this study, the authors report the purification and characterization of antitoxic proteins from the serum of Agkistrodon halys Pallas. Two antitoxic proteins have been successfully isolated by the methods of (NH4)(2)SO(4) fractional precipitation, chromatography and preparative discontinuous polyacrylamide gel electrophoresis (PAGE). We have measured their molecular weights by Sephadex G-150 chromatography and 0.1% SDS-Tris-HCl discontinue PAGE respectively. Antitoxin I was about 138,000+/-40 Da and antitoxin II was about 76,000+/-40 Da, they are all single-chain peptides. We have measured their capacity to neutralize the toxicity of agkistrodotoxin (ATX), and their capacity to inhibit the PLA(2) activity of ATX. The results showed that antitoxin I could increase LD(50) of ATX from 0.25+/-0.05 to 0.445+/-0.13 mg/kg, decrease its PLA(2) activity from 2.36 to 1.72 microm/mg min, and antitoxin II could increase LD(50) of ATX from 0.25+/-0.05 to 0.56+/-0.12 mg/kg, decrease Phospholipase A(2) (PLA(2)) activity from 2.36 to 1.2 microm/mg min. When the natural antitoxins were mixed with different amounts of ATX and inoculated intraperitonially into eight mice, it was found that 0.5 mg antitoxin I could neutralize the toxicity of 0.4 mg ATX and 0.5 mg antitoxin II could neutralize the toxicity of 0.5 mg ATX completely. These antitoxic proteins could neutralize the toxicity of ATX completely and inhibit ATX's PLA(2) activity partially.