期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Purification and Characteristics of Mn-containing Nitrogenase Component Ⅰ
1
作者 黄巨富 汪道涌 +5 位作者 董志刚 汪志平 张华峰 吕玉兵 许祥明 赵颖 《Acta Botanica Sinica》 CSCD 2001年第9期918-922,共5页
A mutant UW 3, which is unable to fix N 2 in the presence of Mo (Nif -) but undergo phenotypic reversal to Nif + under Mo deficiency, was able to grow in Mo- and NH 3-deficient medium containing Mn, and the growt... A mutant UW 3, which is unable to fix N 2 in the presence of Mo (Nif -) but undergo phenotypic reversal to Nif + under Mo deficiency, was able to grow in Mo- and NH 3-deficient medium containing Mn, and the growth was accelerated by Mn at low concentration. A partly purified nitrogenase component Ⅰ protein separated from UW 3 grown in the Mn-containing medium was shown to contain Fe and Mn atoms (ratio of Fe/Mo/Mn: 10.41/0.19/1.00) with C 2H 2- and H +-reducing activity which almost equal to half of that of MoFe protein purified from wild-type mutant of Azotobacter vinelandii Lipmann. This protein was obviously different from MoFe protein in both absorption spectrum and circular dichroism, and the molecular weight of subunits in Mn-containing protein was close to that of α subunit in MoFe protein. The preliminary results indicated that the protein containing Mn might be a nitrogenase component Ⅰ protein. 展开更多
关键词 protein purification protein characteristic nitrogenase protein containing Mn UW 3 mutant of Azotobacter vinelandii
下载PDF
Colonization Pattern of Azospirillum brasilense Yu62 on Maize Roots 被引量:6
2
作者 刘元 陈三凤 李季伦 《Acta Botanica Sinica》 CSCD 2003年第6期748-752,共5页
Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gno... Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gnotobiotically in flask with semi-solid agar medium. Observations were performed with confocal laser scanning microscopy (CLSM) and electron microscopy, respectively, at 8 d and 12 d after inoculation. Confocal laser scanning microscopy showed that A. brasilense Yu62 could penetrate into the cortex tissue, colonizing in the intercellular spaces of the parenchyma cells of the cortex tissue. Transmission and scanning electron microscopy (TEM) showed that the majority of the bacteria colonized on the root surface and only a minority of them resided in the root interior. 展开更多
关键词 green fluorescent protein (GFP) Azospirillum brasilense Yu62 COLONIZATION confocal laser scanning microscopy ( CLSM) transmission electron microscopy (TEM) scanning electron microscopy (SEM)
下载PDF
Crystal Growth of Nitrogenase CrFe Protein and MnFe Protein in Space 被引量:1
3
作者 赵颖 赵剑峰 +4 位作者 吕玉兵 黄巨富 王耀萍 仓怀兴 毕汝昌 《Acta Botanica Sinica》 CSCD 2003年第9期1043-1048,共6页
Nitrogenase CrFe protein and MnFe protein were purified from a mutant strain UW3 of Azotobacter vinelandii Lipmann grown on a medium containing Cr and Mn, respectively. In order to meet the requirement for crystal gro... Nitrogenase CrFe protein and MnFe protein were purified from a mutant strain UW3 of Azotobacter vinelandii Lipmann grown on a medium containing Cr and Mn, respectively. In order to meet the requirement for crystal growth Of O-2-susceptible proteins including nitrogenase in space, crystallization conditions were optimized for the proteins using a simple and suitable device, as a replacement for the cumbersome anaerobic box (dry box), for anaerobic addition of the protein samples. In all used precipitant and protein solutions added in the simplified plexi glass box, CrFe protein and MnFe protein could be crystallized on the spacecraft in one week by the liquid/liquid diffusion method and vapor diffusion by the sitting drop method, respectively. All formed crystals were single on the spacecraft, but under the same condition twin crystals appeared on the ground. The size of the largest crystal grown in space from CrFe protein was 2-fold larger than that on the ground. But the size of the largest crystal grown in space from MnFe protein was not larger than that on the ground. The difference in crystal growth in space between CrFe protein and MnFe protein could be resulted from the crystallization method, rather than the kind of protein. 展开更多
关键词 mutant UW3 of Azotobacter vinelandii O-2-susceptible proteins nitrogenase CrFe protein and MnFe protein crystal growth in space
下载PDF
Purification and Activation In Vitro of MoFe Protein from a nifE Deleted Mutant Strain of Azotobacter vinelandii
4
作者 赵剑峰 赵颖 +3 位作者 汪志平 吕玉兵 潜中兴 黄巨富 《Acta Botanica Sinica》 CSCD 2003年第7期815-819,共5页
The Deltanif E MoFe protein (Deltanif E Av1) was obtained by a chromatography on DE52, Sephacryl S-300 and Q-Sepharose columns from the unheated crude extract of nifE-deleted mutant strain (DJ35) of Azotobacter vinela... The Deltanif E MoFe protein (Deltanif E Av1) was obtained by a chromatography on DE52, Sephacryl S-300 and Q-Sepharose columns from the unheated crude extract of nifE-deleted mutant strain (DJ35) of Azotobacter vinelandii Lipmann. The analysis by SDS-PAGE showed that the Delta nif EAv1 was similar to OP MoFe protein (Av1) of A. vinelandii in the kinds and molecular weights of subunits (alpha and beta subunit). When complemented with nitrogenase Fe protein (M), the A nif EAv1 had hardly any proton-reduction activity, but could be significantly activated by FeMoco extracted from OP Av1. After the Delta nif E Av1 was treated with an excess o-phenanthroline (o-phen) and chromatographied on Sephadex G-25 column under atmosphere of Ar, Delta nif E Av1(C) was obtained. In the presence of both Av2 and MgATP regeneration system, the Delta nif EAv1(C), rather than A nif EAv1, was significantly activated in vitro by a reconstituent solution containing Mn which composed of KMnO4, ferric homocitrate, Na2S, Na2S2O4 (DT) and dithiothreitol (DTT). But in the absence of MgATP or Av2, the activation of Delta nifE Av1(C) did not happen. It indicates that activation of Delta nif EAv1 by RS-Mn requires the pretreatment with o-phen and the simultaneous presence of Av2 and MgATP. 展开更多
关键词 Delta nif E Av1 PURIFICATION activation and assembly in vitro FeMoco and reconstituent solution containing Mn
下载PDF
浅谈化学实验在教学中的重要性
5
作者 伍春乃 《新教育(海南)》 2009年第2期48-48,共1页
在初中化学教学中,实验是化学的灵魂,是化学的魅力和激发学生学习兴趣的主要源泉,更是培养和发展学生思维能力和创新能力的重要方法和手段。
关键词 初中化学教学 学生思维能力 意识倾向 华侨中学 电解水 问题学生 内在规律性 生活实例 设疑 白色固
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部