野生大豆种子蛋白含量差异的生理及结构基础的探讨

利用ＳＤＳ－聚丙烯酰胺凝胶电泳、电子显微镜、蛋白及酰脲含量测定等技术,对高蛋白含量（５０．７％ ）的５０３５９ 和低蛋白含量（４０．８％ ）的５０３０５ 两个野生大豆在种子发育过程中贮藏蛋白积累的速率、蛋白组分合成的起始时间、蛋白体发育的进程以及幼茎的酰脲含量进行了比较研究。结果表明：野生大豆５０３５９的高蛋白含量是与其种子发育过程中较高的植株酰脲含量、较早较快的贮藏蛋白合成及积累速率,液泡中高效的蛋白贮藏方式以及蛋白体在子叶细胞中占有较大体积相联系的     

水平回转对水稻幼苗叶细胞的影响

对在模拟微重力装置上回转１４ 天的水稻幼苗叶细胞进行了亚显微形态、电子探针和细胞酶化学研究。发现叶细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜内钙总量上升、膜外钙总量下降,细胞骨架变得疏松,细胞壁变薄并凹凸不平。叶绿体的基粒和线粒体的内嵴亦有部分变化。其变化机制,首先是细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜上钙泵停止工作,跨膜钙浓度差减小,膜内钙浓度上升,微管、微丝聚合受阻,细胞骨架疏松,分泌泡移动失去导向,从而导致细胞壁变薄等状态     

几种濒危植物及其近缘类群总DNA的提取与鉴定

用低ｐＨ 介质,高盐沉淀蛋白质方法成功地从银杉（Ｃａｔｈａｙａ ａｒｇｙｒｏｐｈｙｌｌａ Ｃｈｕｎ ｅｔＫｕａｎｇ）、矮牡丹（Ｐａｅｏｎｉａ ｓｕｆｆｒｕｔｉｃｏｓａ ｖａｒ． ｓｐｏｎｔａｎｅａ）、南川升麻（Ｃｉｍ ｉｃｉｆｕｇａ ｎａｎｃｈｕａｎｅｎｓｉｓＨｓｉａｏ）、裂叶沙参（Ａｄｅｎｏｐｈｏｒａ ｌｏｂｏｐｈｙｌｌａ）的同属种泡沙参（Ａ． ｐｏｔａｎｉｎｉｉ）等植物中提取和部分纯化了细胞总ＤＮＡ,并对其产率、质量和纯度作了鉴定。此方法的关键是用了一个低ｐＨ提取介质,它能有效防止组织破碎及沉淀大量材料时的电离化作用及酚化合物的进一步氧化。所得ＤＮＡ 不需经氯化铯梯度离心或柱层析,直接可用于限制性片断长度多态性（ＲＦＬＰ）及随机扩增的ＤＮＡ多态性（ＲＡＰＤ）等分子水平的遗传标记。为检测濒危植物的遗传多样性提供了一套迅速、简便和可靠的技术方案     

毛叶香茶菜素的结构订正

我们从安徽省黄山产的大萼香茶菜（Ｒａｂｄｏｓｉａｍａｃｒｏｃａｌｙｘ（Ｄｕｎｎ）Ｈａｒａ）中分得一结晶,其元素分析和１３Ｃ－ＮＭＲ与毛叶香茶菜素［１］完全一致,故推定为毛叶香茶菜素,根据该结晶的元素分析,ＭＳ、ＮＭＲ、ＣＯＳＹ和ＮＯＥＳＹ等光谱数据,其结构应订正为（２）。表１表明：毛叶香茶菜素（２）的分子式由元素分析和高分辨质谱确定为Ｃ２４Ｈ３６Ｏ９,毛叶香茶菜素（１）的分子式由元素分析也应确定为Ｃ２４Ｈ３６Ｏ９。由于赵治清等误将质谱中Ｍ＋－Ｈ２Ｏ碎片离子峰ｍ／ｚ４５０当作分子离子峰（毛叶香茶菜…     

Homology models of two isozymes of manganese peroxidase: Prediction of a Mn(II) binding site

The three-dimensional structures of two isozymes of manganese peroxidase (MnP) have been predicted from homology modeling using lignin peroxidase as a template. Although highly homologous, MnP differs from LiP by the requirement of Mn(II) as an intermediate in its oxidation of substrates. The Mn(II) site is absent in LiP and unique to the MnP family of peroxidases. The model structures were used to identify the unique Mn(II) binding sites, to determine to what extent they were conserved in the two isozymes, and to provide insight into why this site is absent in LiP. For each isozyme of MnP, three candidate Mn(II) binding sites were identified. Energy optimizations of the three possible Mn(II) enzyme complexes allowed the selection of the most favorable Mn(II) binding site as one with the most anionic oxygen moieties best configured to act as ligands for the Mn(II). At the preferred site, the Mn(II) is coordinated to the carboxyl oxygens of Glu-35, Glu-39, and Asp-179, and a propionate group of the heme. The predicted Mn(II) binding site is conserved in both isozymes. Comparison between the residues at this site in MnP and the corresponding residues in LiP shows that two of the three anionic residues in MnP are replaced by neutral residues in LiP, explaining why LiP does not bind Mn(II). © 1994 Wiley-Liss, Inc.     

Systemic amyloidosis in transgenic mice carrying the human mutant transthyretin (Met 30) gene

To analyze the pathologic processes of amyloid deposition in type I familial amyloidotic polyneuropathy (FAP), mice were made transgenic by introducing the human mutant transthyretin (TTR) gene(MT-hMet 30). An inbred strain of mouse, C57 BL/6, was chosen. Transgenic mice were killed using ether anesthesia at 3-mo intervals up to 24 mo after birth. In these transgenic mice, amyloid deposition started in the gastrointestinal tract, cardiovascular system, and kidneys and extended to various other organs and tissues with advancing age. The pattern of amyloid deposition was similar to that observed in human autopsy cases of FAP, except for its absence in the choroid plexus and in the peripheral and autonomic nervous systems. We extracted the amyloid fibrils from kidneys of these mice with a human mutant TTR gene and analyzed them immunochemically and electronmicroscopically. Deposited amyloid was shown to be composed of human mutant TTR and mouse serum amyloid P component. Amyloid fibril from transgenic mice was morphologically and immunohistochemically similar to that of human FAP. The most striking pathologic feature of the transgenic mice was the absence of amyloid deposition in the peripheral and autonomic nervous tissues. Thus, other intrinsic factors may be involved in amyloid deposition in the nervous tissues of human FAP.     

血管活性肠多肽结合核苷酸性质的研究

采用光亲和技术检测了血管活性肠多肽(VIP)与核苷酸之间的相互作用,发现VIP可以特异性结合同位素标记的GTP,还发现未标记的GTP以及其它三磷酸核苷抑制这种结合,这意味着VIP与上述三磷酸核苷之间的结合是一种典型的可逆性的结合反应.发现低浓度的GDP,GMP不但不抑制VIP与同位素标记GTP的结合反应,反而增强这种结合.联系到其它研究者关于GTP影响VIP与其受体结合反应的结果,可认为VIP能可逆性地连接一种三磷酸核苷,这种连接受反应系统中不同核苷酸比例影响,通过这种连接来调节VIP与其受体之间的反应.     

大血藤科植物的分类学研究

作者对大血藤科植物的花性、叶片内部结构形态、花粉形态、染色体核型及过氧化物酶和脂酶同工酶进行了比较研究,结果表明：１）大血藤科植物外形上的两性花,其雄蕊的形态退化、花药始终不开裂,为功能上的雌花,因此其花为单性,同株,同序或异序;１２）首次指出大血藤属植物的染色体数为２ｎ＝２ｘ＝２２,属小型染色体,与木通科植物２ｎ＝２ｘ＝３２、３０、２８的染色体数明显不同,支持Ｓｔａｐｆ（１９２６）将其从木通科分出另立为科的观点;３）单叶和复叶可出现于同一植株上,而且在叶片内部结构、花粉形态、染色体核型、过氧化物酶及脂酶同工酶等性状上,大血藤与单叶血滕间均无实质性的差异,因此将单叶血藤归并于大血藤中。     

沈阳西部污灌水中有机污染物的分析

沈阳西部污灌水中有机污染物的分析刘海玲,张丽珊,姚家彪,于殿臣,朱岩,可夫,姜萍（中国科学院沈阳应用生态研究所,１１００１５）ＡｎａｌｙｓｉｓｏｆＯｒｇａｎｉｃＰｏｌｌｕｔａｎｔｓｉｎＩｒｒｉｇａｔｅｄｓｅｗａｇｅＩｎＷｅｓｔｅｒｎＳｈｅｎｙａｎｇ．...     

Regulation of vasoactive intestinal peptide expression in sympathetic neurons in culture and after axotomy: The role of cholinergic differentiation factor/leukemia inhibitory factor

Vasoactive intestinal peptide (VIP) expression increases in sympathetic neurons when they are grown in dissociated cell or explant cultures and when they are axotomized in vivo. In dissociated cell culture, the magnitude of the VIP increase was reduced when nonneuronal cells were removed and medium conditioned by ganglionic nonneuronal cells increased VIP in neuron-enriched cultures. Antiserum Against cholinergic differentiation factor (also leukemia inhibitory factor; CDF/LIF), but not against ciliary neurotrophic factor, immunoprecipitated this activity. Medium conditioned by sympathetic ganglion explants also contained a VIP-stimulatory molecule that was immunoprecipitated by CDF/LIF antiserum, and CDF/LIF antiserum partially blocked VIP induction in explants. CDF/LIF mRNA was increased in dissociated cell cultures, in ganglion explants and in vivo after axotomy. Our results suggest that CDF/LIF released from ganglionic nonneuronal cells plays an important role in regulating VIP after axotomy. 1994 John Wiley & Sons, Inc.