氯磺酚M与血清蛋白质相互作用的光度研究及分析应用

用于测定稀土等无机离子的显色剂氯磺酚M(chlorosulfophenol M),在pH 4.23的Britton-Robinson(B-R)缓冲介质中,能与生物活性物质血清蛋白质形成有色复合物,λmax为615nm,比试剂本身红移约63nm,表观摩尔吸光系数ε为4.34×105L.mol-1.cm-1,测定蛋白质的线性范围为0~100mg/L(牛血清白蛋白,BSA)。应用于临床中人血清样品总蛋白质的测定,结果与经典方法一致,而且操作简便、线性范围宽,重现性好,基本无干扰。     

苦胺酸偶氮变色酸与血清蛋白质相互作用的分光光度研究

在 p H1 .2的 Clark- Lubs缓冲介质中 ,苦胺酸偶氮变色酸与血清蛋白质作用在室温下能迅速结合形成紫色的复合物 ,其最大吸收波长为 62 5 nm,比苦胺酸偶氮变色酸本身红移了 1 0 0 nm。用分光光度法研究了该结合反应的最佳条件 ,建立了一个测定蛋白质的新方法 ,测定的表观摩尔吸光系数 ε62 5达 2 .72 8× 1 0 5L/mol·cm(牛血清白蛋白 ) ,线性范围为 1 0～ 1 5 0 mg/L。所拟方法简便、快速、选择性好、灵敏度高 ,应用于人血清中总蛋白的测定 ,结果与考马斯亮蓝 G- 2 5 0法一致。     

吡咯红Y-SDS-蛋白质体系的共振光散射光谱研究

在硫酸存在下,微量蛋白质的加入可使吡咯红Y-SDS体系弱的共振光散射信号得到极大的增强。在λ=364 nm处,光散射强度最大,并且光散射增强强度与蛋白质的质量浓度在一定范围内呈线性关系,由此建立了一种测定蛋白质的新的分析方法。对牛血清白蛋白(BSA)和人血清白蛋白(HSA)进行测定,其线性范围分别为0.15~3.6μg/mL和0.06~4.8μg/mL,检测限分别为21.0 ng/mL和12.0 ng/mL。该方法用于人血清样中蛋白总含量的测定,结果令人满意。     

Cu(Ⅱ)-SCN-二元配合物与蛋白质的相互作用的电化学研究

用电化学方法对Cu(Ⅱ)-SCN-二元配合物与牛血清白蛋白(BSA)的相互作用进行了研究,发现在0.04 mol/L的高氯酸介质中,Cu(Ⅱ)-SCN-二元配合物能与牛血清白蛋白生成一种非电活性的复合物,导致Cu(Ⅱ)-SCN-二元配合物的还原峰电流降低,峰电流降低值Δip如在一定范围内与BSA的浓度成线性关系,线性范围为0.5~5.5 mg/L,相关系数为0.994,检测限为0.5mg/L,所以该法可用于蛋白质含量的测定。     

光谱技术研究硫堇与牛血清白蛋白的结合反应

用荧光光谱、紫外可见吸收光谱和圆二色光谱技术研究了生理条件下硫堇(TH)与牛血清白蛋白(BSA)的结合反应.结果表明,硫堇借静电力与牛血清白蛋白发生相互作用并对牛血清白蛋白的荧光以静态方式猝灭,其结合常数为1.155×105L·mol-1、结合位点数为1.835、结合距离2.865 nm.同步荧光和圆二色技术证实TH对BSA的构像有影响.     

邻羟基苯基荧光酮共振瑞利散射法测量蛋白质含量

在pH 8.81的缓冲溶液中,邻羟基苯基荧光酮和牛血清白蛋白结合可使邻羟基苯基荧光酮的光散射信号增强,并且与蛋白质浓度在一定的范围内呈线性关系.据此,运用共振光散射技术,建立了蛋白质定量测定的方法.该方法简单、快速、灵敏,测定牛血清白蛋白的线性范围为1.1×10-6～2.0×10-6 mol/L,检出限为2.9×10-9 mol/L,对合成样品的测定结果令人满意.     

荧光光谱法研究紫草素与牛血清白蛋白的相互作用

采用荧光光谱法研究了紫草素和牛血清白蛋白的相互作用. 实验结果表明,紫草素对牛血清白蛋白的荧光有明显的猝灭作用,其方式为静态猝灭,紫草素与牛血清白蛋白之间发生了分子内非辐射能量转移;紫草素和牛血清白蛋白的结合位点数为1,结合位置距离212位色氨酸残基1.92 nm;温度为22和36℃时,紫草素对牛血清白蛋白荧光的猝灭常数分别为6.96′104和5.91′104 mol/L. 热力学分析表明,紫草素与蛋白之间的结合以静电作用力为主. 同时,紫草素分子含有多个羟基,它们之间还存在氢键作用力.     

维C和左氧氟沙星对白蛋白的荧光淬灭研究

通过荧光光谱法研究了在维生素C存在下左氧氟沙星对牛血清白蛋白的荧光淬灭作用。在模拟生理条件（pH=7.4,37℃）下,根据Stem-Volmer方程,确定了在维生素C存在条件下,左氧氟沙星与牛血清白蛋白的淬灭类型仍为静态淬灭,左氧氟沙星对牛血清白蛋白的荧光淬灭减弱,结合常数和结合位点均变小。为研究左氧氟沙星和维生素对蛋白质构象的影响等提供了重要信息。     

偶氮胭脂红G结合共振光散射法测定人血清样品中的总蛋白

研究了在pH为2.5的BR缓冲酸性介质中,偶氮胭脂红G与牛血清白蛋白(BSA)、人血清白蛋白(HSA)、鸡蛋白蛋白(OVA)及免疫球蛋白(γ-IgG)等蛋白质作用产生共振光散射(RLS)增强信号,最大散射峰位于594nm处。在最佳实验条件下,增强RLS强度在594 nm处与蛋白质浓度呈线性关系,检出限在0.025~0.406μg/mL之间,生物体液中大部分常见物质均不产生干扰。该法应用于人血清样品测定,测定结果与考马斯亮蓝法一致。     

甲基丙烯酸-丙烯酰胺共聚水凝胶的药物释放动力学研究

以甲基丙烯酸、丙烯酰胺为原料,合成了pH敏感甲基丙烯酸-丙烯酰胺共聚水凝胶,研究其牛血清白蛋白释放动力学和释放机理,结果表明:牛血清白蛋白释放具有较好的pH依赖性,丙烯酰胺或交联剂用量的增加,牛血清白蛋白释放量降低;pH 1.0时释放机理为Fickian扩散,pH 6.8时释放机理为非Fickian扩散。     

Very Bright Phycoerythrobilin Chromophore for Fluorescence Biolabeling

Biliproteins have extended the spectral range of fluorescent proteins into the far-red (FR) and near-infrared (NIR) regions. These FR and NIR fluorescent proteins are suitable for the bioimaging of mammalian tissues and are indispensable for multiplex labeling. Their application, however, presents considerable challenges in increasing their brightness, while maintaining emission in FR regions and oligomerization of monomers. Two fluorescent biliprotein triads, termed BDFP1.2/1.6:3.3:1.2/1.6, are reported. In mammalian cells, these triads not only have extremely high brightness in the FR region, but also have monomeric oligomerization. The BDFP1.2 and BDFP1.6 domains covalently bind to biliverdin, which is accessible in most cells. The BDFP3.3 domain noncovalently binds phycoerythrobilin that is added externally. A new method of replacing phycoerythrobilin with proteolytically digested BDFP3.3 facilitates this labeling. BDFP3.3 has a very high fluorescence quantum yield of 66 %, with maximal absorbance at λ=608 nm and fluorescence at λ=619 nm. In BDFP1.2/1.6:3.3:1.2/1.6, the excitation energy that is absorbed in the red region by phycoerythrobilin in the BDFP3.3 domain is transferred to biliverdin in the two BDFP1.2 or BDFP1.6 domains and fluoresces at λ≈670 nm. The combination of BDFP3.3 and BDFP1.2/1.6:3.3:1.2/1.6 can realize dual-color labeling. Labeling various proteins by fusion to these new fluorescent biliproteins is demonstrated in prokaryotic and mammalian cells.     

高效液相色谱法测定染发产品中8种染发剂

建立了高效液相色谱法同时测定8种染发剂的检测方法。样品采用甲醇超声提取,使用Purospher~?STARLPRP-18 endcapped色谱柱分离,以乙腈-0.02 mol/L乙酸铵为流动相,检测波长HC黄2为230 nm,分散蓝1为240 nm,HC红3号、分散紫1和HC橙1为250 nm,HC红1号为270 nm,HC黄4为420 nm,分散黑9为450 nm。该方法在1.0～100.0μg/mL范围内线性良好,相关系数均高于0.999,检出限为0.60～0.95 mg/kg,加标回收率为84.2%～108.4%,相对标准偏差为1.3%～4.5%。该方法简便快速、结果准确,能够满足染发产品中8种染发剂的分析要求。     

两种方法测定赤泥中可溶性硫酸根

赤泥中含有硫酸根离子,其含量对赤泥的回收利用过程带来麻烦,也对回收产品的质量有影响.本文用2种方法测定赤泥中的硫酸根并进行对比,希望找到简便、快捷、准确、精密度高的实验方法.铬酸钡分光光度法:在410nm硫酸根在0～6.00mg·(50mL)-1范围内与铬酸根吸光度呈线性关系,线性回归方程:y=0.1747x-0.00...     

The origin of the red emission in n-ZnO nanotubes/p-GaN white light emitting diodes

In this article, the electroluminescence (EL) spectra of zinc oxide (ZnO) nanotubes/p-GaN light emitting diodes (LEDs) annealed in different ambients (argon, air, oxygen, and nitrogen) have been investigated. The ZnO nanotubes by aqueous chemical growth (ACG) technique on p-GaN substrates were obtained. The as-grown ZnO nanotubes were annealed in different ambients at 600°C for 30 min. The EL investigations showed that air, oxygen, and nitrogen annealing ambients have strongly affected the deep level emission bands in ZnO. It was concluded from the EL investigation that more than one deep level defect is involved in the red emission appearing between 620 and 750 nm and that the red emission in ZnO can be attributed to oxygen interstitials (O_i) appearing in the range from 620 nm (1.99 eV) to 690 nm (1.79 eV), and to oxygen vacancies (V_o) appearing in the range from 690 nm (1.79 eV) to 750 nm (1.65 eV). The annealing ambients, especially the nitrogen ambient, were also found to greatly influence the color-rendering properties and increase the CRI of the as - grown LEDs from 87 to 96.     

Influence of Green,Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.)

The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 μmol m⁻² s⁻¹ for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 μmol m⁻² s⁻¹) and was lowered with decreased light intensity (70–80 μmol m⁻² s⁻¹). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment.     

A Large Stokes Shift Fluorescent Protein Constructed from the Fusion of Red Fluorescent mCherry and Far-Red Fluorescent BDFP1.6

Phycobiliproteins are constituents of phycobilisomes that can harvest orange, red, and far-red light for photosynthesis in cyanobacteria and red algae. Phycobiliproteins in the phycobilisome cores, such as allophycocyanins, absorb far-red light to funnel energy to the reaction centers. Therefore, allophycocyanin subunits have been engineered as far-red fluorescent proteins, such as BDFP1.6. However, most current fluorescent probes have small Stokes shifts, which limit their applications in multicolor bioimaging. mCherry is an excellent fluorescent protein that has maximal emittance in the red spectral range and a high fluorescence quantum yield, and thus, can be used as a donor for energy transfer to a far-red acceptor, such as BDFP1.6, by FRET. In this study, mCherry was fused with BDFP1.6, which resulted in a highly bright far-red fluorescent protein, BDFP2.0, with a large Stokes shift (≈79 nm). The excitation energy was absorbed maximally at 587 nm by mCherry and transferred to BDFP1.6 efficiently; thus emitting strong far-red fluorescence maximally at 666 nm. The effective brightness of BDFP2.0 in mammalian cells was 4.2-fold higher than that of iRFP670, which has been reported as the brightest far-red fluorescent protein. The large Stokes shift of BDFP2.0 facilitates multicolor bioimaging. Therefore, BDFP2.0 not only biolabels mammalian cells, including human cells, but also biolabels various intracellular components in dual-color imaging.     

The synthesis of microgels composed of polyelectrolytes

Microgels composed of dimethylaminopropylacryl amide (MAPA) or sodium salt of vinylbenzenesulfonic acid (VBS) were prepared by the crosslinking of primary polymers Poly(MAPA-co-acrylamide) or poly(VBS-co-acrylamide) with glutaraldehyde in aqueous solutions. Almost mono disperse spheric microgels with the diameter of 120 nm were obtained in the very wide concentration range (up to 5 w/v% for the former and 12 w/v% for the latter). In the copolymerization of MAPA and N-methyloylacrylamide, microgel with the diameter of 120–140 nm was formed during polymerization.     

Effect of Hydrothermal Conditions on the Morphology of Colloidal Boehmite Particles: Implications for Fibril Formation and Monodispersity

The synthesis of colloidal boehmite (AlOOH) is studied by heating basic aluminum chloride solutions under constant stirring. The temperature and Al₂O₃: Cl molar ratio influence the product morphology. Synthesis at 140°C generates highly fibrous polycrystalline particles that are on average 360 nm long, 30 nm broad, and 8 nm thick. They contain 0.11 mol of excess H₂O per 1 mol of AlOOH. Synthesis at temperatures between 140° and 190°C produces broader fibrils and less excess H₂O. Preparation at 220°C eventually produces fully crystalline platelike boehmite particles about 260 nm long, 95 nm broad, and 14 nm thick, without excess H₂O. Fibril synthesis requires an Al₂O₃:Cl molar ratio exceeding 1.0 to yield noncoagulated particles. The fibrils are fairly monodisperse with 20% standard deviation in their length for an Al₂O₃: Cl molar ratio about 1.0.     

1-(2,3,5-三氮唑偶氮)-2-萘酚的合成及其与镍的显色反应研究

合成了 1 - ( 2 ,3,5 -三氮唑偶氮 ) - 2 -萘酚 (简称 TZAN) ,研究了它与镍的显色反应。结果表明 :在 p H7.0～ 8.0的水溶液中镍与 TZAN形成一种稳定的红色配合物 ,其最大吸收波长位于5 2 8.8nm处 ,表观摩尔吸光系数ε=3.40× 1 0 4 L /mol· cm,配合物的组成 Ni2 + ∶ TZAN=1∶ 2。镍浓度在 0～ 1 .2 mg/L范围内服从比尔定律。在氟化铵和硫脲的存在下 ,可直接测定合金中的微量镍