构建及表达小麦高分子量容蛋白基因5′端调控序列缺失突变体嵌合质粒

通过定点突变，在小麦高分子量（ＨＭＷ）谷蛋白基因５′上游调控序列的ＴＡＴＡｂｏｘ与基因翻译起始密码子ＡＴＧ之间，改变三个碱基，产生新的ＢａｍＨⅠ内切酶位点．在调控序列中，选择四个合适的内切酶，对上游序列进行缺失，分离到四个大小分别为２４００、６１０、４４０和１１０ｂｐ的含有不同调控元件的ＨＭＷ谷蛋白基因启动子，与质粒ｐＢＩ１０１．１的报告基因ＧＵＳ重组，构建了四个嵌合质粒ｐＷＧ２４００、ｐＷＧ６００、ｐＷＧ４４０和ｐＷＧ１００．经基因枪、微束激光和ＰＥＧ等方法将ｐＷＧ２４００转化玉米胚乳悬浮细胞，ＧＵＳ基因获得表达．这为进一步研究ＨＭＷ谷蛋白基因的调控机理奠定了基础．     

新型显色基质法鲎试验对肺部革兰氏阴性菌感染患者的诊断意义

应用新型显色基质法鲎试验（ＮＣＬＡ）测定４１例肺部革兰阴性（Ｇ＾－）细菌感染患者）Ｇ组）；３２例肺部非革兰氏阴性细菌感染患者（非Ｇ组）；４２例无细菌感染的肺病患者（无感染组）的血浆内毒素浓度、并与１００例健康者（对照）比较，Ｇ组血浆内毒素水平明显高于对照组，非Ｇ组及无感染组（Ｐ均〈０．０１）。提示新型显色基质法鲎试验有助于肺部Ｇ细菌感染作出快速，灵敏的诊断。     

马铃薯PGBSS—GUS融合基因在块茎中专一性表达的初步研究

从ＧＢＳＳ基因克隆上，酶切得到５上游区１．２ｋｂ的序列，与ＧＵＳ报告基基因融合，构建了ＰＧＢＳＳ１．２表达载体，通过农杆菌介导的方式，将ＰＧＢＳＳ１．２转和马铃薯品种Ｄｅｓｉｒｅｅ，卡那霉素筛选获得抗性再生植和微薯，利用ＰＣＲ特异性扩增和Ｓｏｕｔｈｅｒｎ Ｂｌｏｔｔｉｎｇ的方法证明了融合基因在马铃薯基因组中的整合，Ｘ－Ｇｌｕｅ活体染色表明，微薯切片具有高ＧＵＳ酶活性，而茎段中ＧＵＳ活性相对较低，初     

水稻RSSG8基因启动子与GUS融合基因的构建及在烟草中的瞬间表达

使用染色体步移(Genome walking)法，从籼稻(Oryza sativa subsp．indica)桂朝2号基因组中克隆到长度为471bp的水稻精细胞优势表达基因RSSG8的启动子片段R8PN，并进行了全序列测定和分析．该段序列中含有3个CAAT-box，6个Gobox和多种植物顺式作用元件，但没有发现典型的TATA-box，推测为一种特殊的启动子结构，为了鉴定RSSG8基因的基本启动子元件，将二条长度不同的5’端侧翼区缺失体(分别长471bp，260bp)定向插入载体pBI121中，取代原有的CaMV 35S启动子，构了驱动报告基因GUS的植物表达载体pRGUS1，pRGUS2，通过农杆菌介导的瞬时表达法转化烟草叶片和花粉，快速鉴定启动子片段中起关键作用的区域，结果显示两个缺失片段都能启动GUS的表达，可以初步判定这两个片段具有启动子功能。     

Influence of high pressure treatment on rheological and other properties of egg white

Abstract

The paper deals with the influence of high pressure treatment of fresh egg white on its properties and protein composition (individual amino-acids predicted as a function of pressure and time levels). The rheological properties are changed by high pressure from Newtonian to non-Newtonian behaviour, with increasing apparent viscosity as the pressure and time increased. The pH, whipping ability, foam stability, gel strength of heat induced gels after treatment and the whole protein content, were also predicted.

The results showed that the foam stability is increased with increasing pressure and time of processing. The foam volume is also increased with pressure. The pH did not change with pressure or time of processing. Composition of proteins as indicated by individual amino-acids did not exhibit statistically important changes. Gel strength of heat induced gels prepared from previously pressured liquid whites showed no important change of values with pressure or time of treatment. The modulus of elasticity showed a decrease for samples pressured to 400 MPa for 5 up to 15 minutes.     

On The Fluorometric Method for the Measurement of β-Cyanoalanine Synthase Activity

Abstract

A modification of a fluorescence assay method for β-cyanoalanine synthase has been described which involves the direct coupling of the product of cyanide and cysteine to resazurin, to produce the fluorescent resosurfin, The fluorescence produced was found to be directly proportional to the rate of the reaction.     

Chemical composition,antioxidant and cytotoxic activities of extracts from the leaves of Smilax brasiliensis Sprengel (Smilacaceae)

The antioxidant and cytotoxic activities of petroleum ether and methanol extracts, fatty acids and methyl esters from leaves of Smilax brasiliensis were evaluated, and the composition of the extracts was determined. Palmitic, linoleic and linolenic acids were major components of the extracts. For antioxidant activity, all samples exhibited IC₅₀ values lower than BHT (2,6-di-tert-butyl-4-methylphenol). The extracts, fatty acids and methyl esters from S. brasiliensis presented no toxicity to larvae of the brine shrimp, Artemia salina. Among the purified substances, only methyl linolenate showed toxicity (LD₅₀ = 21.47 μg/mL). This study showed, for the first time, the composition of petroleum ether and methanol extracts from S. brasiliensis leaves, as well as the antioxidant and cytotoxic activities of extracts, fatty acids and methyl esters.     

A novel efficient medium for chromogenic catalysis of tetramethylbenzidine with horseradish peroxidase

The traditional surfactant sodium dodecyl sulfate (SDS) and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF₄]) have been combined to create a novel efficient medium for chromogenic catalysis of 3,3',5,5'-tetramethylbenzidine with horseradish peroxidase in presence of H₂O₂. The results have shown the [Emim][BF₄] in the mediums can promote the rate of formation of the blue chromogen, the SDS is responsible for the stabilization of the blue chromogen due to the electrostatic attraction between positively charged blue chromogen and the negatively charged surfactant. The SDS/[Emim][BF₄] combination not only enhance catalytic activity of HRP remarkably but also stabilize the blue chromogen formed in the HRP oxidation of the substrate TMB compared to the conventional medium. Based on the superior combination of SDS and [Emim][BF₄], the colorimetric assay for detecting HRP activity and H₂O₂ concentration was established. This work demonstrates a novel efficient medium for chromogenic catalysis with potential applications in biosensors and clinical diagnosis.     

Ni(II) and Cu(II) complexes of bidentate thiosemicarbazone ligand: Synthesis,structural, theoretical,biological studies and molecular modeling

The conventional condensation and refluxing process was employed to synthesize Ni(II) and Cu(II) complexes of Methylcarbamatethiosemicarbazone ligand. Reactions were carried out at the pH of 7. The molar ratio of the ligand and metal salt was 2:1. The structures of the synthesized metal complexes were suggested by different analytical techniques such as magnetic susceptibility, molar conductance, IR, EPR and UV spectroscopy. Experimental studies confirmed the octahedral geometry for all the complexes. The geometry of the ligand and complexes were also confirmed by theoretical studies. The complexes were investigated for biological action against pathogenic fungi (C. krusei, C. albican) and bacteria (S. aureus, E. coli). The antimicrobial results confirmed superior inhibition potential of the metal complexes as compared with the parent ligand. The enhanced antimicrobial activities might be due to the chelation. Molecular-docking assays confirmed the strong interaction of ligand with target antimicrobial protein DNA gyrase-B.