安普那韦与人血清白蛋白之间的相互作用

在体外模拟人体生理环境,采用光谱法并结合分子对接技术,研究了安普那韦与人血清白蛋白(HSA)之间的相互作用.荧光光谱表明:安普那韦可以增强HSA的荧光强度.通过对结合常数和热力学常数的计算可知,安普那韦和HSA之间的作用力主要是疏水和静电作用力;紫外-可见光谱显示:安普那韦能够增加HSA的吸收峰强度,表明两者之间发生了相互作用.三维荧光光谱也显示:加入安普那韦后,HSA的斯托克斯位移从62 nm增加到了86 nm,说明安普那韦可以使HSA的微环境极性增加,疏水性减弱;从圆二色光谱的研究结果可知:随着安普那韦的加入,HSA的α-螺旋结构含量从18.38%增加到了63.62%,说明安普那韦的存在改变了HSA的二级结构.分子对接研究结果表明:安普那韦与HSA的作用位点位于HSA的ⅡA结构域,而同步荧光光谱的分析进一步证明了这一点.研究结果为进一步研究安普那韦在体内与血清白蛋白的相互作用提供了一定的理论参考.     

河北省承接国际产业转移路径研究——基于改进产业梯度系数的视角

以河北省为例,依据本土产业结构的现状与特点,运用产业梯度系数确定优势产业及需承接的重点产业,实现本地产业和转入产业的优势互补和产业升级,走资源节约型、环境友好型的新工业化道路。     

不同中药组方对高尿酸血症大鼠的影响

研究不同中药组方对血尿酸及相关代谢指标水平的影响.将大鼠随机分为10组:模型对照组,阳性对照组,中药组方A、B、C、D高、低剂量组,利用氧嗪酸钾构建大鼠高尿酸血症模型,分别给药30 d.给药27 d后测定部分大鼠血清尿酸,以确定造模成功与否及样品是否有疗效.给药30 d后全部动物测定血糖(GLU)、总胆固醇(CHOL)、甘油三酯(TG)、尿素(UREA)、肌酐(CREA)、尿酸(UA)、肾脏指数等指标.与模型组比较,给药27 d后各样品组动物血清尿酸浓度均有所降低;给药30 d后,A、B、C样品高、低剂量组均能降低高尿酸血症模型大鼠的血尿酸水平;给药30 d后,各样品组GLU、CHOL、TG、UREA、CREA等指标水平均无明显变化;给药30 d后,A、B、C各样品高剂量组均能明显降低高尿酸血症模型大鼠的肾脏指数.A、B、C组样品均能降低高尿酸血症大鼠血尿酸水平,初步印象其对肾脏具有一定的保护作用.     

人血清白蛋白融合技术研究进展

人血清白蛋白是血液中含量最丰富的蛋白,它半衰期长,且具有运输药物的功能,这使其成为理想的药物栽体.作为延长药物半衰期的新技术,白蛋白融合技术是近年来发展迅速、应用广泛的蛋白质工程技术.通过共价偶联、非共价偶联、纳米包裹和融合蛋白的方式可实现白蛋白与药物分子的偶联,使药物分子的药代动力学得到明显改善.系统介绍了白蛋白融合技术的主要方式、进展以及发展方向.随着白蛋白和相关受体蛋白作用机制的研究不断深入,基于结构的白蛋白融合技术将进一步提高白蛋白融合技术在长效药物开发中的应用.     

乙氧基血根碱与人血清白蛋白的相互作用

研究了血根碱与人血清白蛋白（HSA）之间的结合特征．采用荧光光谱法,计算在不同温度下乙氧基血根碱与HSA相互作用的结合常数与结合位点数．实验结果显示,在290K,300K,310K时乙氧基血根碱与人血清白蛋白的结合常数分别为1．081×10^5L·mol-1,7．784×10^4L·mol-1,2．397×10^5L·mol-1．结合位点数分别为1．013,0．979,1．071．二者之间的主要作用力为氢键和范德华力．这表明血根碱与人血清白蛋白之间作用生成了无荧光效应的复合物,属静态猝灭．     

中美数学教材设计的一项比较研究——以“勾股定理及其逆定理”为例

中小学数学教材中对知识的设计和处理方式在数学教学中起着重要作用.通过比较美国教材《发现几何》与国内人教版《初中数学》在"勾股定理及其逆定理"设计上的差异,发现2本教材在设计上各有优势,前者设计注重学生的动手操作,侧重学习者的个性学习,力求在做中学,关注学习者对几何的兴趣;后者设计注重知识的完整体系,对演绎推理的要求比重明显大于对合情推理的要求,关注学习者和教师严谨、准确的数学体验.     

ATP男子单打不同场地类型比赛得分方式的对比研究

运用文献资料、录像统计、数理统计等研究方法,对网球运动员在不同场地的比赛得分情况进行对比研究,探讨男子网球运动员在不同场地类型比赛的得失分规律,研究表明:在红土球场比赛中,运动员的主动失误较少,技战术发挥最稳定,但各项技术的运用较为单一;在草地球场比赛中,运动员的进攻意识非常明显,主动得分的效率最高;在硬地球场比赛中,运动员各项技术使用较为均衡,战术运用灵活多变,但失误率最高.     

A new chromatographic method for fast separation of active proteins

A new method with only a single chromatographic column to accomplish the separation of intact protein molecules by the combination of ion exchange chromatography and hydrophobic interaction chromatography is firstly presented. By selecting twice a suitable stationary phase, mobile phase, buffer exchange condition, and sample injection, some proteins usually required to separate with two-dimensional chromatography can now be accomplished only using the single column in one hour. In addition, the separated proteins can maintain their original three-or four-dimensional molecular structure. It would be expected that this method can also provide a new thought for sample pre-fractionation in proteomic investigation, especially, for the limitation of sample source.     

Analysis of biomarkers for the cross-linkage of formaldehyde with bovine serum albumin peptides

Formaldehyde, a well-known environmental toxic hazard, has been found to produce endogenously via semicarbazide-sensitive amine oxidase-catalyzed oxidative deamination of methylamine. In diabetes, the activity of SSAO has been found to increase with a subsequent increase in endogenous formaldehyde production. It has been postulated that SSAO-induced production of formaldehyde may be involved in the alteration of protein structure, which may subsequently cause protein deposition associated with chronic pathological disorders. Formaldehyde has also been found to react （cross-link） with amino group of the N-terminal amino acid residue and with the side-chains of arginine, cysteine, histidine and lysine residues. Therefore, formaldehyde may be responsible, at least in part, for protein cross-linkage, oxidative stress and cytotoxicity. The cross-linking of formaldehyde with bovine serum albumin was studied using LC-MS and Mascot database. The peptides sequence for control BSA （untreated） digested with trypsin was matched in the online database search query by exporting the MS/MS data to online MASCOT database. In this way, a total of twenty-seven peptides were matched in the database search query. These twenty-seven peptides were then searched manually in all of the tryptic BSA samples treated with different concentrations of FA that were incubated in different time intervals. Six formaldehyde-treated BSA peptides （FKDLGEEHFK, HLVDEPQNLIK, KVPQVSTPTLVEVSR, RPCFSALTPDETYVPK, LVNELTEFAK, DAFLGSFLYEYSR） were found to be the possible markers for formaldehyde-protein/peptides adducts.     

Proteomic analysis of long-term salinity stress-responsive proteins in <Emphasis Type="Italic">Thellungiella halophila</Emphasis> leaves

Salinity is one of the most severe environmental factors that may impair crop productivity. A proteomic study based on two-dimensional gel electrophoresis is performed in order to analyze the long-term salinity stress response of Thellungiella halophila, an Arabidopsis-related halophyte. Four-week-old seedlings are exposed to long-term salinity treatment. The total crude proteins are extracted from leaf blades, separated by 2-DE, stained with Coomassie Brilliant Blue, and differentially displayed spots are identified by MALDI-TOF MS or QTOF MS/MS. Among 900 protein spots reproducibly detected on each gel, 30 spots exhibit significant change and some of them are identified. The identified proteins include not only some previously characterized stress-responsive proteins such as TIR-NBS-LRR class disease resistance protein, ferritin-1, and pathogenesis-related protein 5, but also some proteins related to energy pathway, metabolism, RNA processing and protein degradation, as well as proteins with unknown functions. The possible functions of these proteins in salinity tolerance of T. halophila are discussed and it is suggested that the long-term salinity tolerance of T. halophila is achieved, at least partly, by enhancing defense system, adjusting energy and metabolic pathway and maintaining RNA structure.