米氏凯伦藻溶血毒素的溶血反应特征

探讨了温度、pH值、二价阳离子等对米氏凯伦藻(Karenia mikimotoi Hasen)溶血毒素溶血活性的影响,分析了米氏凯伦藻溶血毒素的溶血反应特征.结果表明,实验室培养米氏凯伦藻的溶血活性约为64.69±6.43 HU L-1,单个藻细胞的溶血活性为6.17±0.61×10-6 HU;在实验温度(0～37℃)下,溶血活性随温度的增加而增加;pH6.0时的溶血活性最高;Cu2+、Mg2+、Mn2+、Ca2+、Co2+、Zn2+和Hg2+等对米氏凯伦藻的溶血活性的影响不同.离子浓度为5 mmol/L时,Hg2+的抑制作用最强.高浓度Hg2+对红细胞的集合效应不但阻止了Hg2+进入血细胞诱导的溶血作用,而且阻止了毒素对细胞膜的破坏,但这种抑制作用可被EDTA消除.     

蜂毒溶血肽类似物定量构效关系计算分析

采用HyperChem7．0结构分析软件,对蜂毒溶血肽类似物的分予体积等结构参数进行了计算分析．分别利用多元线性回归、BP-神经网络计算法进行统计分析,获得两个相关性好的QsAR（quantitative structure-function relationship）模型．结果显示,蜂毒肽溶血活性与生成热、键合能、表面积、分予体积、极化能、醇水分配系数、水舍能相关．为降低溶血作用,指出在设计蜂毒肽结构时应尽量避免螺旋状结构．少用疏水性氨基酸．     

Studies on Hemolytic Action of a Hemolysin Produced by Vibrio mimicus

Some properties and mechanism of action of a hemolysin (VMH) produced by an enteropathogenic Vibrio mimicus strain was examined. VMH was heat-labile and inhibited by addition of divalent cations, including Ca²⁺, Mg²⁺ and Mn²⁺. The hemolysis by VMH was inhibited by incubating with gangliosides, suggesting that the ganglioside was the binding site on the erythrocyte membrane for VMH. Existence of a galactose moiety on reducing end of the ganglioside molecule and a sialic acid on the galactose moiety was suggested to be important for the binding of VMH molecule. Colloid osmotic manner of the hemolysis by VMH was demonstrated.     

Characterization of the Hemolytic Properties of an Extract from Phaeocystis globosa Scherffel

Phaeocystis globosa Scherffel, an organism that causes harmful algal blooms, is a genus of the family Prymnesiophyta (or Haptophyta) with eurythermal and euryhaline characteristics. P. globosa has been confirmed to produce hemolytic substances, which are a mixture of liposaccharides. In the present study, the hemolytic properties of extract ofP. globosa are analyzed further. The effects of temperature, pH,different divalent cations, and membrane lipids on extract-induced hemolysis are discussed, as is the possible hemolytic mechanism. The results of the present study showed that the hemolytic activity of the extract was approximately 127.1 hemolytic units (HU)/L. The hemolytic reaction became fastest and a 50% decrease in absorbance was induced at 30 min at 37 ℃, and at pH 7.0; Hg2 was the strongest inhibitor of the hemolysis compared with the other divalent cations and many membrane lipids, except for phosphatidic acid, inhibited the hemolytic activity to different degrees. These results suggest that the toxin may make pores in the surface of red blood cells and that Hg2 either combines with the hemolysin or closes the pores,hence inhibiting its further hemolytic reaction. The toxin probably has no specific membrane receptor in the red blood cell membrane.     

鱼精蛋白抗菌机制的研究

鱼精蛋白是一种存在于各类动物精巢组织中的多聚阳离子肽,其抗菌性很早就被所知,然而它的抗菌机理却一直未能得到很清楚的了解。现存在的机理有2种:一种认为鱼精蛋白与细菌细胞壁结合,通过破坏细胞壁的形成来达到抑菌效果;另一种认为鱼精蛋白破坏了细胞能量的转换、营养物质的吸收功能,细胞质膜是鱼精蛋白攻击的对象。事实上,作者认为,鱼精蛋白的抗菌效果可能是通过以上2种方式共同作用的结果,因而它的抗菌机理也可能是这两种机理的叠加,这还需进一步的研究证明。     

Characterization of the Hemolytic Properties of an Extract from Phaeocystis globosa Scherffel

Phaeocystis globosa Scherffel, an organism that causes harmful algal blooms, is a genus of the family Prymnesiophyta (or Haptophyta) with eurythermal and euryhaline characteristics. P. globosa has been confirmed to produce hemolytic substances, which are a mixture of liposaccharides. In the present study, the hemolytic properties of extract of P. globosa are analyzed further. The effects of temperature, pH,different divalent cations, and membrane lipids on extract-induced hemolysis are discussed, as is the possible hemolytic mechanism. The results of the present study showed that the hemolytic activity of the extract was approximately 127.1 hemolytic units (HU)/L. The hemolytic reaction became fastest and a 50% decrease in absorbance was induced at 30 min at 37℃, and at pH 7.0; Hg^2 was the strongest inhibitor of the hemolysis compared with the other divalent cations and many membrane lipids, except for phosphatidic acid, inhibited the hemolytic activity to different degrees. These results suggest that the toxin may make pores in the surface of red blood cells and that Hg^2 either combines with the hemolysin or closes the pores,hence inhibiting its further hemolytic reaction. The toxin probably has no specific membrane receptor in the red blood cell membrane.     

含硒抗体酶性质的研究

在成功地制备了具有谷胱甘肽过氧化物酶（ＧＰＸ）活性含硒抗体酶（Ｓｅ－ａｂｚｙｍｅ）的基础上,我们筛选了制备Ｓｅ－ａｂｚｙｍｅ的最佳条件,并对其理化性质及酶学性质和稳定性进行了深入的研究。结果表明,Ｓｅ－ａｂｚｙｍｅ的等电点为６．９５和７．０８,一为１５８ｋｄ;适ＰＨ和最适温度范围比天然酶宽广;抗体酶的贮藏稳定性比天然酶高。高Ｘ射线光电子能谱技术测得在Ｓｅ－ａｂｚｙｍｅ中含硒量为５ｍｏｌＳｅ／ｍｏｌ     

大鼠精核蛋白的纯化

用大鼠睾丸制备长形精子细胞核及用附睾制备的附睾精子核,用盐酸胍法提取总碱性蛋白（Ｔｏｔａｌ　ｂａｓｉｃ　ｐｒｏｔｅｉｎ,ＴＢＰ）。通过Ｓｅｐｈａｄｅｘ　Ｇ－１００分子筛层析,其第三峰用５％ＴＣＡ沉淀,得到纯大鼠精核蛋白（Ｒａｔ　ｐｒｏｔａｍｉｎｅ,ＲＰ）。ＲＰ也可用ＴＢＰ通过ＨＰＬＣ反相柱得到纯化,ＲＰ位于２６％－２８％乙腈梯度。     

藻胆蛋白短肽性质的研究

在不同温度、ｐＨ条件下,测定了藻胆蛋白短肽中天然色素基团的稳定性,确定了最适保存条件。研究了样品中乙醇含量、微量元素及稳定剂β－胡萝卜素和维生素Ｃ对藻胆蛋白短肽的影响。找出了可使其更稳定的添加剂。     

红斑性肢痛症相关痘病毒血清免疫学特征的研究

本文从四个方面综合报道了红斑性肢痛症相关痘病毒(ERPV)血清免疫学特征的研究结果。血清学鉴定表明,ERPV为正痘病毒属内成员,但与正痘病毒属内成员痘苗病毒和鼠痘病毒具有中和抗原表位差异。流行性红斑性肢痛症患者血清中含有抗ERPV的中和抗体和抗ERPVA型包涵体IgG抗体,其检出率明显高于当地未发病者和美国人群的检出率。     

胆碱脱氢酶光谱性质的研究

胆碱脱氢酶（ＣＤＨ）蛋白质部分内源荧光发射峰在３３５ｎｍ,并不受底物的影响,但底物可改变辅基ＦＡＤ部分的内源荧光光谱。应用ＦＴＩＲ技术研究了增溶ＣＤＨ的二级结构,其结果如下：５３．４％α－螺旋,２４．５％β－片层,１３．９％３１０－螺旋及０．５％β－回折。在ＣＤＨ处于非底物结合状态时,分子内部结构表现为α－螺旋以及β－片层优势构象,呈现出球状蛋白样的空间结构特征。在与底物作用过程中,３１０－螺旋的比例逐渐上升至４２％左右,与此同时α－螺旋结构则降低到３５％。提示了底物诱导ＣＤＨ分子内部发生了蛋白分子的重新折叠。