凤眼莲根分泌物氨基酸组分对根际肠杆菌属F2细菌的趋化作用

凤眼莲(Eichhornia crassipes)的根分泌物中含有Met等多种氨基酸,其中Met、GABA、Gly、Ala、Asp、Ser、Val和Leu(10^-7～10^-2mol·L^-1)均对凤眼莲的根际肠杆菌属F₂(Enterobacter sp.F₂)细菌有强烈的正趋化作用;Glu、Thr和His(10^-7～10^-3mol·L^-1)也对该菌有一定的正趋化作用;而Lys、Cys、Arg、Tyr、Pro、Asn、Gln、Ile、Phe和Typ则对该菌表现出一定的负趋化作用.对细菌的正趋化作用存在一个趋化物的最适浓度范围.具有正趋化作用的氨基酸在凤眼莲根际的浓度都较高,而具有负趋化作用的浓度则较低,这正是凤眼莲与该根际细菌结合为根际微生态系统的原因之一.     

一种具有纤溶活性的枯草杆菌蛋白激酶的研究──Ⅰ高产酶菌株的筛选与鉴定

本文主要阐述了一种具有纤溶活性的枯草杆菌（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ）蛋白激酶产生菌株的筛选与鉴定的研究结果。作者从初筛的１２株Ｂａｃｉｌｌｕｓｓｕｂｌｉｌｉｓ菌中,通过对固体发酵和液体发酵所产生的枯草杆菌蛋白激酶,用琼脂糖－纤维蛋白平板法测其活性,经比较不同菌株的活性,筛选出两株高产酶菌株：Ｂ．ｓｕｂｔｉｌｉｓＨＷ—１２和Ｂ．ｓｕｂｔｉｌｉｓＨＷ—３。同时对菌体和菌落形态特点、生理生化反应进行了鉴定,认为Ｂ．ＳｕｂｔｉｌｉｓＨＷ－１２菌株可用来做为发酵生产该酶的菌种。     

悬钩子属种质的评价

在进行了７省悬钩子资源调查的基础上,在南京建立了悬钩子属田间基因库。３年来对田间基因库内保存并开花结果的３０个种进行了开花结果性状的记栽和评价。内容包括果实特征,糖、酸、维生素类、氨基酸、矿质元素含量分析,染色体计数等。分析了种间和种内多样性物存在及在良种选育中利用的可能性。     

迷宫漏斗蛛Agelena labyrinthica的染色体(蜘蛛目:漏斗蛛科)

报告迷宫漏斗蛛的染色体数目、形态结构和性染色体组成。结果表明,迷宫漏斗蛛体细胞染色体数目是:雄性2n=42,雌性2n=44,性别决定机制属X_1X_2O型。X染色体是全部染色体中最长的和最短的2个(对)。染色体似乎均为端或亚端着丝粒染色体,这由C-显带标本分析所证实,没有亚中着丝粒染色体的证据。C-带标本分析表明,常染色体中,各条染色体的C-带纹,其大小和染色深浅无明显差异,但X_2染色体上有明显宽的C-带纹。C-显带处理没有得到稳定的有重复性的带纹。     

朱砂叶螨羧酸脂酶最优测试条件的选择

应用二次回归通用旋转组合设计,对朱砂叶螨离体羧酸酯酶测试过程中所需缓冲液pH值、恒温时间、反应温度及底物浓度,设立4因子5水平试验,在考虑4个因子主效应和互作效应的情况下,筛选测试羧酸酯酶的最优条件组合。     

人乳腺癌cAMP结合蛋白

建立了测定人乳腺癌胞浆ｃＡＭＰ结合蛋白（ｃＡＭＰｂ．ｐ．）方法。综合研究了其温度、保温时间、配体浓度、稳定性等条件。ｃＡＭＰｂ．ｐ．的Ｋ_Ｄ值为２．９０×１０~（－８）ｍｏｌ／Ｌ．并测定了６０例雌激素受体（ＥＲ）Ｆｕ性乳腺癌标本的ｃＡＭＰｂ．ｐ．含量。此组病人术后均接受系统的内分泌治疗,ＥＲ／ｃＡＭＰｂｐ,比值范围为７．７～３６２×１０~（－３）,ＥＲ／ｃＡＭＰｂ．ｐ．比值≥４０×１０~（－３）的五年生存率明显高于比值＜４０×１０~（－３）组,（ｐ＜０．００５）．表明测定ＥＲ／ｃＡＭＰｂ．ｐ．比值对预测患者内分泌治疗疗效,优于单独测定ＥＲ．     

人前列腺生长因子的分离纯化及生物活性鉴定

从人良性增生前列腺组织中经硫酸铵沉淀和肝素－琼脂糖凝胶层析纯化出人前列腺生长因子（ｈＰＧＦ）,纯化倍数约１０００倍,ＳＤＳ－ＰＡＧＥ和等电聚焦电泳示分子量约为１７ｋＤ、等电点同标准ｂＦＧＦ,利用分离培养的人前列腺间质成纤维细胞进行活性鉴定,发现以１．３～１．７ｍｏｌ／ＬＮａＣｌ洗脱部分为ｈＰＧＦ,活性最高,对间质成纤维细胞有显著刺激增殖作用。     

远交系小鼠胚胎干细胞系的建立及嵌合鼠的获得

ＥＳ细胞（ＥｍｂｒｙｏｎｉｃＳｔｅｍＣｅｌｌｓ）是来源于小鼠早期胚胎的多潜能干细胞,它可以在体外大量培养。并以单细胞的形式注射到早期胚胎里,发育为嵌合体。到目前为止,通常使用的１２９小鼠品系是来源于近交系（ｉｎｂｒｅｄ）小鼠的胚胎．与之相比,远交系小鼠应当具有较强的生命力和抗病能力。曾有人报道过建成了远交系小鼠胚胎干细胞系,但是尚没有见到获得嵌合鼠的报道。有人甚至认为：由于不同品系小鼠所具有的遗传背景不同,有的小鼠不能建成ＥＳ细胞系。最近,本实验室在这方面做了有益的探索,成功地建成了远交系小鼠胚胎干细胞系,并在这里报导首例用远交系小鼠胚胎干细胞系培育成功嵌合体小鼠。采用源于Ｓｗｉｓｓ小鼠远交群的昆明（ＫＭ）品系小鼠囊胚建成了三个小鼠胚胎干细胞系（ＫＥ１．ＫＥ２．ＫＥ５）。核型正常率均达到７０％以上。自第八代起分批冻存,复苏后,培养至第１２代,消化成单细胞,通过囊胚显微注射,将其注射到６１５品系小鼠胚胎。在幸存的幼鼠中获得了一只来源于ＫＥ１细胞的嵌合鼠（Ｔａｂｌｅ１）．其毛色表现为受体鼠（６１５）的白色中嵌合有供体鼠（ＫＭ）的黑褐色（ＰｌａｔｅＩ－Ａ）．嵌合鼠与受体鼠的杂交后代鼠中仍然出现了受体鼠的毛色类型（     

Magnesium Adenosine 5[prime]-Triphosphate-Energized Transport of Glutathione-S-Conjugates by Plant Vacuolar Membrane Vesicles

By characterization of the uptake of glutathione-S-conjugates, principally dinitrophenyl-S-glutathione (DNP-GS), by vacuolar membrane vesicles, we demonstrate that a subset of energy-dependent transport processes in plants are not H+-coupled but instead are directly energized by MgATP. The most salient features of this transport pathway are: (a) its specific, obligate requirement for MgATP as energy source; (b) the necessity for hydrolysis of the [gamma]-phosphate of MgATP for uptake; (c) the insensitivity of uptake to uncouplers of the transtonoplast H+ gradient (carbonylcyanide 4-trifluoromethoxyphenylhydrazone, gramicidin-D, and NH4Cl); (d) its pronounced sensitivity to vanadate and partial inhibition by vinblastine and verapamil; (e) the lack of chemical modification of DNP-GS either during or after transport; (f) the capacity of S-conjugates of chloroacetanilide herbicides, such as metolachlor-GS, but not free herbicide, to inhibit uptake; and (g) the ability of vacuolar membrane vesicles purified from a broad range of plant species, including Arabidopsis, Beta, Vigna, and Zea, to mediate MgATP-dependent, H+-electrochemical potential difference-independent DNP-GS uptake. On the basis of these findings it is proposed that the transport of DNP-GS across the vacuolar membrane of plant cells is catalyzed by a glutathione-conjugate transporter that directly employs MgATP rather than the energy contained in the transtonoplast H+-electrochemical potential difference to drive uptake. The broad distribution of the vacuolar DNP-GS transporter and its inhibition by metolachlor-GS are consistent with the notion that it plays a general role in the vacuolar sequestration of glutathione-conjugable cytotoxic agents.     

Phosphoryl amino acids: Common origin for nucleic acids and protein

A series of compounds (DAP-AA) composed of an amino acid (AA) and a dialkyl phosphoryl group (DAP) is the basic elements of life chemistry. Self-catalysis of DAP-AA gives the self-assembly oligopeptides, even in aqueous medium at 38°C. The oligo-nucleotides could also be assembled from nucleosides' phosphorylation by DAP-AA. DAP-AA acts as the energy source as well as the phosphoryl donor for the synthesis of nuclic Acids and protein. A general expression for the self assembly system is proposed.