竹叶青蛇毒凝集素的分离纯化及特性研究

利用亲和层析的方法从竹叶青蛇的蛇毒中分离纯化到一种新的凝集素。这种凝集素是半乳糖的,其糖结合活性依赖于钙离子;还可使兔红细胞凝集。ＳＤＳ－ＰＡＧＥ的结果表明,在生理条件下这种凝集素是不均一的,包含单体、二体、三体和四体。其中主要是二体。单体分子量为２０ｋｄ。此凝集素的等电点为８．５。Ｎ端２０个氨基酸的序列已经测定,与响尾蛇毒凝集素的同源性很高,两者的半胱氨酸的位置相同。     

红花菜豆凝集素的糖结合专一性

经肼解、Ｂｉｏ－Ｇｅｌ Ｐ－２柱层析、ＮａＢ＾３Ｈ４和ＮａＢＨ４还原,制备各种来源的、氚标记在还原末端的、还原末端为Ｎ－乙酰氨基葡萄糖醇的混合寡糖,经Ｂｉｏ－Ｇｅｌ Ｐ－４凝胶柱分离,以及用糖苷酶酶解,制备了各种不同类型的氚标记的寡糖。这些寡糖在固定化的ＰＣＬ－Ｓｅｐｈａｒｏｓｅ柱上亲和层析,根据各种类型寡糖在ＰＣＬ－Ｓｅｐｈａｒｏｓｅ柱上的层析行为,确定红花菜豆（矮生红花变种）凝集素（ＰＣＬ）的     

凝集素碎片的糖结合活性

用固相合成法分别合成了羊蹄甲、小扁豆和欧洲百脉根３种植物凝集素中的某些糖结合活性部位的肽段。用毛细管电泳法观察到这些肽段和拟糖蛋白以及寡糖之间有一定的结合能力,而且表现出相对的专一性。     

半夏凝集素的糖结合活性研究

半夏凝集素可与甘露聚糖结合。本文以ＰＴＬ与＾１２５Ｉ标记的甘露聚糖的结合活性为指标,观察了一些金属离子对ＰＴＬ的糖结合活性的影响,并对ＰＴＬ的糖结合专一性作了较系统的研究。结果表明常见的金属离子或ＥＤＴＡ对其糖结合活性无显著影响,但Ｋ＾＋可明显增加ＰＴＬ的糖结合活性。大多数单糖,二糖不抑制ＰＴＬ与甘露聚糖的结合,但一些疏水配基形成的糖苷可产生显著的抑制效应。ＰＴＬ专一与高甘露糖型糖链结合。     

竹叶青蛇毒磷脂酶A2的分离纯化和性质研究

竹叶青蛇毒磷脂酶Ａ_２的分离纯化和性质研究冯波,吴卫甲,钱嵘,王克夷,周元聪（中国科学院上海生物化学研究所,２０００３１）关键词竹叶青蛇毒,磷脂酶Ａ_２;血小板聚集磷脂酶Ａ。在哺乳动物胰脏和蛇毒毒液中含量较丰富,其中蛇毒磷脂酶Ａ。除能水解甘油磷脂的第二...     

竹叶青属毒蛇的毒素研究进展

蛇毒含多种生物活性成分,其中多数为酶类和活性肽类。随着蛇毒毒理学、药物学、生物化学和分子生物学的发展,蛇毒的许多组分已得到分离纯化和序列测定,并广泛应用于理论研究和临床应用。竹叶青蛇属是中国常见的毒蛇,近年来对其应用研究的报道颇多,就竹叶青属毒蛇的种类与分布,及其蛇毒组分的分离纯化、理化性质、分子克隆表达等方面的研究资料进行了概括和综述。     

蛇毒C-型凝集素研究进展

蛇毒中含有丰富的非酶活性C－型凝集素蛋白,根据其结构及功能的差异,该类蛋白可分为Ca^2 依赖的有糖基识别活性的C－型真凝集素及无糖基识别活性的C－型凝集素样蛋白。C－型真凝集素的结构相似度高,而功能却较为单一,具有特异性糖结合活性;C－型凝集样蛋白的结构变异度大,活性亦具有多样性。后者能通过特异性的蛋白质－蛋白质相互作用而作用于血液凝固系统及血小板,从而发挥抗凝或促凝的生理功能。     

红花菜豆凝集素糖—结合肽段的分离

红花菜豆凝集素糖－结合肽段的分离施炜星宋金芳孙册（中国科学院上海生物化学研究所,上海２０００３１）关键词红花菜豆凝集素;糖－结合肽段;分离收稿日期：１９９６－０６－０８;接收日期：１９９６－０９－０３。凝集素的生物学作用和功能与其糖－结合专一性密切相...     

半夏凝集素的糖结合活性研究

半夏凝集素(PTL)可与甘露聚糖结合。本文以PTL与~(125)I标记的甘露聚糖的结合活性为指标,观察了一些金属离子对PTL的糖结合活性的影响,井对PTL的糖结合专一性作了较系统的研究。结果表明常见的金属离子或EDTA对其糖结合活性无显著影响,但K~+可明显增加PTL的糖结合活性。大多数单糖,二糖不抑制PTL与甘露聚糖的结合,但一些疏水配基形成的糖苷可产生显著的抑制效应。PTL专一与高甘露糖型糖链结合。     

菜花烙铁头蛇毒C-型凝集素基因的克隆与序列分析

从菜花烙铁头蛇（Trimeresurus jerdonii)的毒腺中提取mRNA,采用RT-PCR技术进行体外扩增,将扩增产物克隆到PMD18-T载体中,最后筛选出一个编码凝集素的基因,命名为TJL。由TJL基因序列推导的氨基酸序列中包含分别由23和135个氨基酸残基组成的信号肽和成熟肽。氨基酸序列比较分析表明,TJL含有半乳糖结合位点和钙离子结合位点,与蝰科蛇毒凝集素TSL、PAL、APL和RSL的同源性较高（87.4%-90.4%）,与眼镜蛇科蛇毒凝集素BML的同源性较低（61.5%)。     

坛紫菜凝集素的糖结合专一性和细胞凝集作用

坛紫菜的磷酸盐缓冲液浸取液,经硫酸铵沉淀和DEAE－Sepharose,SephadexG-100二步层析纯化,获得纯化的坛紫菜凝集素（PHL）。该凝集素能与3种单糖（阿拉伯糖,半乳糖,木糖）及麦芽糖专一性结合,其中与麦芽糖结合最强。细胞凝集实验结果显示,PHL能凝集兔,绵羊及鸡红细胞而不能凝集鸭,鸽子及人血红细胞,PHL还能凝集海洋微藻－绿色巴夫藻和淡水微藻－蛋白核小球藻,它们的凝集活性与藻细胞密度有关。不同状态的细菌和酵母细胞对PHL反应不同,表明随着细胞状态的改变,细胞表面的凝集素受体也随之发生变化。     

抗龟壳花及赤尾鲐蛇毒血清治疗竹叶青蛇伤3例

我院 2 0 0 0年期间使用台湾产抗龟壳花及赤尾鲐蛇毒血清治疗竹叶青蛇 ( Trimercsurusstejnegeri schmidt) [1] 咬伤 3例 ,疗效较好。现报告如下。1　临床资料1 .1　一般资料　在本组 3例病人中 ,男 2例 ,女1例 ;年龄分别为 65岁 ,32岁 ,35岁 ;职业 :专业户 1例 ,农民 2例 ;其中咬伤手部 2例 ,足部 1例。1 .2　治疗方法　给予抗龟壳花蛇及赤尾鲐蛇毒血清一剂量 (含 1 0 0 0抗毒单位以上 )稀释于 30 0 ml生理盐水中 ,皮试阴性后静脉滴注。如注射后局部或全身症状仍继续恶化 ,则应每隔 30 min至 2 h再注射一剂量至全身症状改善。同时给予抗生…     

热毒宁注射液治疗竹叶青蛇咬伤的临床观察

目的观察中成药热毒宁注射液对竹叶青蛇咬伤的治疗作用。方法将246例竹叶青蛇咬伤的患者随机分为两组,对照组给予常规治疗,治疗组在常规治疗的基础上加用热毒宁注射液20m1静脉点滴,每天1次。观察两组的临床表现,记录患者肿痛完全消退时间、止痛时间、局部坏死发生情况及治愈情况、住院时间,INR、PT、APTT等凝血功能指标变化。结果治疗组治愈率为90．24％,对照组治愈率为67．48％,两组比较有显著性差异（P〈O．05）;治疗组肿痛完全消退时间、止痛时间、局部坏死发生情况及治愈情况、住院时间及INR、PT、APTT等凝血功能指标变化与对照组比较有显著性差异（P〈0．05）。结论热毒宁注射液对竹叶青蛇咬伤有显著疗效。     

Offshore insular variation in the diet of the Taiwanese bamboo viper Trimeresurus stejnegeri (Schmidt)

Dietary data were ascertained for 229 T. stejnegeri (snout vent length >300mm) from 36 localities throughout the main island of Taiwan and the outlying Orchid (Lanyu) and Green (Ludau) Islands. Twenty nine percent of the snakes were devoid of any prey, and of the snakes containing prey, 43% of the cases were unidentifiable. This relatively large proportion of unidentifiable prey items (observed in the hindgut) may reflect either rapid digestion of amphibian prey and/or rapid venting of feces as an evolutionary adaptation to arboreal life. Trimeresurus stejnegeri appears euryphagous, taking primarily amphibians, but additionally reptilian, mammalian and insect prey. There was no discrepancy in prey composition based on comparisons of where the prey item was recorded in the digestive tract. No sexual variation in diet composition was evident, although males were more likely to contain prey than females, indicating the utilisation of different foraging strategies on similar sympatric prey items. Variation in diet composition was observed between mainland Taiwan and offshore islands, which is most likely the result of differences in prey availability.     

Purification and Properties of a Lectin from the Fruitbodies of Flammulina velutipes

A lectin was purified to homogeneity from the fruitbodies of Flammulina velutipes by conventional purification procedures. The purified lectin was demonstrated to be a dimeric protein consisting of two identical subunits with an apparent molecular mass of 11 kDa. The lectin was an acidic protein with a pI value of 5.4, and devoid of cysteine, methionine, and histidine as amino acid constituents. Its hemagglutinating activity was totally unaffected by mono- and oligosaccharides and glycosides, but inhibited by some desialylated glycoproteins. Immunological assays revealed that no protein cross-reacting with rabbit anti-i⁷. velutipes lectin antibody was apparently present in vegetatively growing mycelia but was distributed throughout the fruitbody at different concentrations.     

Properties of the Cortical Granule Lectin Isolated from Xenopus Eggs

The cortical granule lectin that participates in forming the fertilization layer in Xenopus laevis was isolated and partially characterized. About 400 μg of lectin was purified from 5 mg of crude exudate by chromatography on Sepharose 6B and Concanavalin A-conjugated Sepharose 4B columns and electrophoretic separation on polyacrylamide gel. The lectin has a molecular weight of 550 Kd and is composed of two species of polypeptides (46 Kd and 42 Kd). The lectin gave a single precipitin line against material in the prefertilization layer in an agglutination reaction on an agarose plate. The agglutination reaction involved D-galactoside residues and metal ions. The lectin formed an electron-dense layer on the outer surface of the vitelline coat of oviducal eggs covered with the prefertilization layer, but on the outer surface of jelly layer, not on that of the vitelline coat of jellied eggs. Although the jelly could be agglutinated by the lectin, the possibility that the jelly layer is the site of fertilization layer formation was excluded by the fact that the prefertilization layer is the first to meet the cortical granule lectin during normal fertilization.