G138P定点突变对葡萄糖异构酶热稳定性的改善

通过分子设计,确定Ｇｌｙ１３８为改善葡萄糖异构酶（ＧＩ）热稳定性的目标氨基酸。用双引物法对ＧＩ基因进行体外定点突变,构建了ＧＩ突变体Ｇ１３８Ｐ。含突变体的重组质粒ｐＴＫＤ－ＧＩＧ１３８Ｐ在Ｅ．ｃｏｌｉＫ３８菌株中表达。ＧＩＧ１３８Ｐ与野生型ＧＩ比较实验表明：（１）ＧＩＧ１３８Ｐ的热失活半衰期约是野生型ＧＩ的２倍;（２）ＧＩＧ１３８Ｐ的最适反应温度提高了１０￣１２℃;（３）ＧＩＧ１３８Ｐ的比活与野生     

用蛋白质工程方法改变葡萄糖异构酶最适pH和最适温度

用寡核苷酸诱导的定点突变方法构建了葡萄糖异构酶基因的突变体（Ｎ１８４Ｄ和Ａ１９８Ｃ）。含突变体的重组质粒ｐＴＫＤ－ＧＩ１（Ｎ１８４Ｄ）和ｐＴＫＤ－ＧＩ２（Ａ１９８ｃ）在Ｅ．ｃｏｌｉＫ３８菌株中表达,用ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ ＦＦ和Ｓｅｐｈａｃｒｙｌ Ｓ－３００ＨＲ柱层析分离纯化突变酶。与野生型葡萄糖异构酶比较实验表明：（１）突变酶Ｎ１８４Ｄ的最适ｐＨ值下降了１个单位;等电点下降了０．６个单位     

纤溶酶原激活物抑制因子—1突变体E350G,E351K的构建及性质研究

利用ＰＣＲ扩增和合成突变引物的方法,将ＰＡＩ－１的Ｇｌｕ３５０和Ｇｌｕ３５１分别突变为Ｇｌｙ和Ｌｙｓ在大肠杆菌中表达并分离纯化突变体ＰＡＩ－１（Ｅ３５０Ｇ,Ｅ３５１Ｋ）有 酸胍激活并以ＥＬＩＳＡ法确定它与野生型ｒＰＡＩ－１的相对含量,通过对ｕ－ＰＡ抑制的动力学研究表明,突变体与野生型ｒＰＡＩ－１相比,对ｕ－ＰＡ和ｔ－ＰＡ的抑制活性都有明显下降,由活性态向潜伏态转变的半寿期也由０．８３ｈ缩短为０．５     

纤溶酶原激活物抑制因子－1突变体E350G，E351K的构建及性质研究

利用ＰＣＲ扩增和合成突变引物的方法,将ＰＡＬ－１的Ｇｌｕ３５０和Ｇｌｕ３５１分别突变为Ｇｌｙ和Ｌｙｓ,在大肠杆菌中表达并分离纯化突变体ＰＡＬ－１（Ｅ３５０Ｇ,Ｅ３５１Ｋ）,用盐酸胍激活并以ＥＬＩＳＡ法确定它与野生型ｒＰＡＩ－１的相对含量。通过对ｕ－ＰＡ,ｔ－ＰＡ抑制的动力学研究表明,突变体与野生型ｒＰＡＩ－１相比,对ｕ－ＰＡ和ｔ－ＰＡ的抑制活性都有明显下降,由活性态向潜伏态转变的半寿期也由０．８３ｈ缩短为０．５７ｈ。     

鳜鱼传染性脾肾坏死病毒(ISKNV)PCR检测方法的建立及虹彩病毒新证据

利用真鲷虹彩病毒（ＲＳＩＶ）核苷酸还原酶小亚单位（ＲＮＲＳ）基因保守区设计的一对引物,建立了鳜鱼传染性脾肾坏死病毒（ＩＳＫＮＶ）特异的ＰＣＲ检测体系。运用该体系检测ＩＳＫＮＶ,具有简便、快速、敏感、特异等特点,为诊断与预防ＩＳＫＮＶ提供了一个重要的手段。通过对ＰＣＲ产物的克隆与序列分析,发现ＩＳＫＮＶ ＰＣＲ扩增产物与ＲＳＩＶ ＲＮＲＳ基因相应序列的同源性很高,达到９２．５％,进一步证明ＩＳＫＮＶ     

STUDIES ON THE PATTERN OF MEGASPOROGENESIS AND MICROTUBULAR CYTOSKELETON CHANGES IN CYMBIDIUM SINENSE

ＳＴＵＤＩＥＳＯＮＴＨＥＰＡＴＴＥＲＮＯＦＭＥＧＡＳＰＯＲＯＧＥＮＥＳＩＳＡＮＤＭＩＣＲＯＴＵＢＵＬＡＲＣＹＴＯＳＫＥＬＥＴＯＮＣＨＡＮＧＥＳＩＮＣＹＭＢＩＤＩＵＭＳＩＮＥＮＳＥ￥Ｓ．Ｙ．ＺｅｅＸ．Ｌ．Ｙｅ（１ＢｏｔａｎｙＤｅｐａｒｔｍｅｎｔ,Ｕｎｉ...     

THE LASER TOMOGRAPHICAL METHOD USINGMINIMUM OF PROJECTION FOR BIOLOGICAL OBJECT STRUCTURE STUDY

ＴＨＥＬＡＳＥＲＴＯＭＯＧＲＡＰＨＩＣＡＬＭＥＴＨＯＤＵＳＩＮＧＭＩＮＩＭＵＭＯＦＰＲＯＪＥＣＴＩＯＮＦＯＲＢＩＯＬＯＧＩＣＡＬＯＢＪＥＣＴＳＴＲＵＣＴＵＲＥＳＴＵＤＹＹｕｒｉＮ．Ｋｕｌｃｈｉｎ;ＯｌｅｇＢ．Ｖｉｔｒｉｋ;ＯｌｅｇＶ．Ｋｉｒｉｃｈｅｉ...     

电融合技术在植物细胞工程中的应用现状

电融合技术在植物细胞工程中的应用现状王天池,林葵（福建农学院园艺系福州３５０００２）ＡＲＥＶＩＥＷＯＮＴＨＥＡＰＰＬＩＣＡＴＩＯＮＯＦＥＬＥＣＴＲＯＦＵＳＩＯＮＩＮＰＬＡＮＴＣＥＬＬＥＮＧＩＮＥＥＲＩＮＧ￥ＷａｎｇＴｉａｎ－ｃｈｉ;ＬｉｎＫｕｉ（Ｆｕ...     

GFP转基因指示系统建立的研究

ＧＦＰ（绿色荧光蛋白）是存在于发光水母体内的一种吸收蓝光或紫外光（３９５ｎｍ）后能够发出绿色荧光的天然蛋白质。本文报道了将ＧＦＰ表达质粒导入ＢＨＫ、ＤＫ、ＲＫ等真核细胞,建立ＧＦＰ真核细胞转基因指示系统。研究表明,ＧＦＰ在ＢＨＫ、ＤＫ、ＲＫ等传代细胞中表达的最佳条件是３３℃,ｐＨ７．２、５％ＣＯ２和转染后４８ｈ观察等。并对野生型ＧＦＰ和突变型ＧＦＰ的发光强度进行了比较,结果表明,在相同条件下,突变型ＧＦＰ的荧光比野生型的强     

银杏胚胎发育研究述评──兼论银杏系统发育

银杏胚胎发育研究述评──兼论银杏系统发育邢世岩,孙霞（山东省林业学校泰安２７１０００）ＡＲＥＶＩＥＷＯＮＴＨＥＥＭＢＲＹＯＬＯＧＹＯＦＧＩＮＫＧＯＢＯＬＯＢＡＷＩＴＨＡＤＩＳＣＵＳＳＩＯＮＯＮＴＨＥＰＨＹＴＯＧＥＮＥＴＩＣＤＥＶＥＬＯＰＭＥＮＴ￥Ｘｉ...     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

The mechanism of hatching of eggs of Haemonchus contortus

Fluid collected from hatching eggs of Haemonchus contortus contained a lipase which hydrolysed 2-naphthyl laurate (about 0·7 μmol naphthol freed /h/10⁶ eggs). The fluid also hydrolysed l-leucinamide (about 2·3 μmol leucine freed/h/10⁶ eggs). The fluid when added to normal or heated eggs caused ‘hatching’. ‘Hatching’ also occurred in exsheathing fluid from infective juveniles and in a preparation of pancreatic lipase containing leucine aminopeptidase. A purified mammalian leucine aminopeptidase in combination with several different lipases did not attack egg shells.The ‘spontaneous’ hatching of eggs of H. contortus was strongly inhibited by 1,10-phenanthroline, 10^?3M, and this inhibition was reversed by Zn²⁺. However, the inhibition of ‘hatching’ of eggs in externally applied hatching fluid, or the hydrolysis of leucinamide in hatching fluid was generally less marked.