人血清白蛋白与手性药物相巨作用的毛细管电泳研究Ⅰ.液相预柱毛细管电泳技术定量可靠性的考察

以药物Verapamil（VER）与人血清白蛋白（HSA）相互作用体系中游离的药物对映体浓度定量测定为目标,建立了一项适用于相互作用研究的液相预柱毛细管电泳（LPC－CE）技术。通过对该技术的考察,确定了这项技术的定量可靠性。在生理pH值条件下（pH7.4,离子强度I=0．17）,使药物与人血清白蛋白达到结合平衡。在毛细管电泳手性拆分[pH2.5缓冲浪;三甲基-β-环糊精（TM－β-CD）浓度为45mmol／L]柱（32cm×50μm）内预先注入一段生理pH缓冲液,形成一段液相预柱（2．8cm）。     

液相预柱毛细管电泳技术在手性药物对映体与白蛋白相互作用研究中的应用

在对碱性药物吡啶茚胺、四氢萘唑啉、去甲肾素茶碱和维拉帕米(verapamil)等药物手性拆分的基础上,运用液相预柱毛细管电泳（LPC-CE）技术,建立了对药物对映体与人血清白蛋白（HSA）相互作用体系中对映体浓度的检测方法.　该技术利用HSA与药物在生理pH下的电泳特性差异,使HSA留在预柱内或反向流出,不进入手性拆分区域,从而消除白蛋白对药物对映体拆分及浓度检测的干扰.　对维拉帕米对映体与HSA结合参数以及多药物组分竞争结合的研究表明,该技术为多种药物与蛋白共存的复杂体系研究提供了一条有效的途径.     

聚乙类吡咯烷酮动态涂敷毛细管电泳柱分离碱性蛋白质

以聚乙烯吡咯烷酮（ＰＶＰ）为添加剂对毛细管柱进行动态修饰,用于碱性蛋白分离。对４种碱性蛋白质进行分离,实验结果表明聚乙烯吡咯烷酮能够很了地抑制电不渗流（ＥＯＦ）及碱性蛋白在石英毛细管壁上的吸附作用。在ｐＨ４．０,ＰＶＰ浓度（Ｗ／Ｖ）为０．４％时,ＥＯＦ仅为１．３５×１０＾－９ｍ＾２／Ｖ．ｓ,平均柱效可达５×１０＾５理论塔板数／ｍ。每次运行之间（ｎ＝６）,天与天之间（ｎ＝６）,迁移时间的相对标准偏差     

稀土离子及胺和氨基酸的高效毛细管区带电泳电导检测

用自制高效毛细管电泳装置研究毛细管电泳电导检测，由用阴离子交换膜管制作的导电接口连接电泳毛细管和电导池，高电压被有效隔离，实现柱后电导检测，用长６０ｃｍ、内径５０μｍ石英毛细管，以ｐＨ４．０的７×１０￣（－３）ｍｏｌ／ＬＮａＡｃ￣（－２）×１０￣（－３）ｍｏｌ／ＬＨＩＢＡ－ＨＡＣ溶液为载体，在１８ｋＶ电压下，轻重三种稀土Ｎｄ、Ｇｄ、Ｙｂ的混合物８ｍｉｎ内完成分离检测。用上述毛细管，以ｐＨ为５．８的５×１０￣（－３）ｍｏｌ／ＬＮａＡｃ－ＨＡＣ溶液为载体，在２０ｋＶ电压下乙二胺、三乙胺、组氨酸、谷氨酸混合有机物７．５ｍｉｎ内完成分离检测。     

分子相互作用的毛细管区带电泳/迎头分析研究

以生命科学中提出的对分离和定量分析有较高要求的研究课题为目标,将迎头分析（ＦＡ）与毛细管区带电泳（ＣＺＥ）相结合,运用毛细管区带电泳／迎头分析（ＣＺＥ／ＦＡ）技术,进行碱性药物ｐｒｏｐｒａｎｏｌｏｌ与人血清白蛋白（ＨＳＡ）平衡体系中相互作用参数的研究 。     

毛细管区带电泳分离小麦种子醇溶蛋白的研究

利用毛细管区带电泳（ＣＺＥ）检测了在不同电泳条件下分离小麦种子醇溶蛋白的效果。结果显示,用碱性缓冲液（０．０６ｍｏｌ／Ｌ硼酸钠,ｐＨ９．０,并含有２０％乙腈和１％ＳＤＳ）及４７ｃｍ×５０μｍｉ．ｄ．毛细管柱,在１５ｋＶ电压和３０℃的条件下可获得较高的分辨度和重复性。     

莨菪类生物碱毛细管电泳分析

采用毛细管区带电泳方法对阿托品（ＤＬ－莨菪碱）、东莨菪碱、山莨菪碱和樟柳碱进 行了系统分离，以 ５０ ｍｍｏｌ／Ｌ磷酸盐缓冲液（ｐＨ ８．０）－四氢呋喃（９：１，Ｖ／Ｖ）作背景电介质， 操作电压为１１ ｋＶ，柱温２４℃，电迁移进样５ ｋＶ×５ｓ，柱上２００ｎｍ检测，４种莨菪类生物碱 可在４０ ｃｍ×５０μｍ的石英毛细管柱上５．５ｍｉｎ之内实现基线分离。     

二烯丙基聚乙二醇20M交联键合型毛细管电泳柱的制备及其评价

本将聚乙二醇２０Ｍ改性为二烯丙基聚乙二醇２０Ｍ，使其更容易在毛细管壁进行，交联和键合，采用超动态涂柱技术，实现了快速制备二烯丙基聚乙二醇２０Ｍ交联键合型毛细管电泳柱，该制柱方法具有简单，速度快，制柱重复性高的特点，用四种碱性蛋白对所制的柱进行评价，平均柱效可达５×１０＾５理论塔板数／米，每次运行之间（Ｎ＝６），天与天之间（Ｎ＝３），以及柱与柱之间（Ｎ＝３）的迁移时间的标准偏差（ＲＳＤ％）在０．２     

抗心律失常新药氯苄律定及其相关物质的毛细管电泳分离与方法耐用性评价

采用毛细管区带电泳方法对抗心律失常新药氯苄律定及其合成前体盐酸黄连素和四氢黄连素进行了系统分离,以８０ ｍｍｏｌ／Ｌ磷酸盐缓冲液（ｐＨ ２．５）－乙醇（５：１,Ｖ／ Ｖ）为背景电介质,操作电压 １０ ｋＶ,毛细管柱温 ２５℃,电迁移进样 ４ ｋＶ ｘ ６ ｓ,柱上 ２３０ ｎｍ检测,盐酸黄连素、四氢黄连素、氯苄律定及内标物盐酸奎宁可在 ２０ ｃｍ ｘ ２５ μｍ涂层毛细管上 ６．０ ｍｉｎ之内实现基线分离。对优选的分离条件进行方法耐用性评价,其中乙醇含量和毛细管柱温显著影响电泳分离结果。     

以万古霉素为手性选择剂的氨基酸对映体的毛细管电泳快速分离

建立了以万古霉素为手性分离选择剂的毛细管电泳氨基酸对映体快速分离的方法。向缓冲溶液中加入０．００２％（Ｗ／Ｖ）的（１,５－二甲基－１,５－二氮杂十一烷亚甲基聚Ｎ－甲溴化物（ｈｅｘａｄｉｍｅｔｈｒｉｎｅ ｂｒｏｍｉｄｅ ＨＤＢ）做电渗流改性剂,使电渗流的迁移方向反转,与分析物方向一致,缩短了分析时间。此外,ＨＤＢ还使毛细管壁得到动态修饰,减少了万古霉素在毛细管壁上的吸附,从而提高了柱效。考察了缓冲溶     

人血清白蛋白与手性药物相互作用的毛细管电泳研究Ⅱ.药物对映体竞争结合参数的测定

 运用毛细管电泳（CE）技术,在对碱性药物Verapamil（VER）手性拆分的基础上对Verapamil与人血清白蛋白（HSA）平行体系进行了相互作用研究。通过定量HSA－VER体系中VER对映体的浓度,建立对映体对结合位点竞争的理论方程,获得了R和S型药物对映体与HSA的结合常数,其值分别为K（R）-VER=2．7×103×（±4．4×102）和K（S）-VER=8．5×102（±1.0×102）。实验证实,HSA具有手性选择性,与（R）－VER的结合强于与（S）-VER的结合,结合比随着HSA与（±）VER的浓度比而变化。     

Capillary electrophoresis study of human serum albumin binding to basic drugs

Summary The applicability of capillary electrophoresis/frontal analysis (CE/FA) for determining the binding constants of the drugs propranolol (PRO) and verapamil (VER) to human serum albumin (HSA) was investigated. After direct hydrodynamic injection of a drug-HAS mixture solution into a coated capillary (32 cm × 50 μm i.d.), the basic drug was eluted as a zonal peak with a plateau region under condition of phosphate buffer (pH 7.4; ionic strength 0.17) at 12 kV positive running voltage. The unbound drug concentrations measured from the plateau peak heights had good correlation coefficients,r>0.999. Employing the Scatchard plot, the Klotz plot and nonlinear regression, the drug protein binding parameters, the binding constant and the number of binding sites on one protein molecule, were obtained. The binding constant obtained was compared to a reported equilibrium dialysis result and they are basically in good agreement.     

高效液相色谱法测定大鼠神经组织中的硝酸盐和亚硝酸盐

 建立了大鼠神经组织中亚硝酸盐和硝酸盐的高效液相色谱测定方法,以用于研究一氧化氮在糖尿病慢性神经病变中的作用。在1 μmol/L～25 μmol/L的浓度范围内,NO2-和NO3-的峰面积与浓度的线性相关系数>0.991;最低检测浓度分别为0.2 μmol/L和0.5 μmol/L;日内、日间相对标准偏差<14%。对各实验组大鼠的初步测定结果表明,糖尿病组及糖尿病胰岛素(IGF)治疗组的NO2-和NO3-水平均低于对照组。 关键词：高效液相色谱法;一氧化氮;硝酸盐;亚硝酸盐;糖尿病神经病变     

酮洛芬与蛋白结合作用的高效液相色谱-迎头分析法研究及其与高效毛细管电泳-迎头分析法的比较

采用高效液相色谱-迎头分析法(HPLC-FA),以67 mmol/L (pH 7.4, I=0.17 mol/L) 的等渗磷酸盐缓冲液为流动相,Pinkerton GFF　Ⅱ-S5-80内表面反相柱(150 mm×4.6 mm i.d., 5 μm)为固定相,254 nm下检测,研究了酮洛芬与人血清白蛋白(HSA)的结合作用,通过非线性回归参数估算求得酮洛芬与HSA的结合参数。与高效毛细管电泳-迎头分析法(HPCE-FA)相比,HPLC-FA法具有高灵敏度的优势,但进样量较大,分析时间较长。HPLC-F     

Microchip capillary electrophoresis for frontal analysis of free bilirubin and study of its interaction with human serum albumin

To meet the need for bedside monitoring of free bilirubin for neonates under critical conditions, a microfluidic chip was fabricated and tested for its coupling with CE/frontal analysis (FA) to determine free bilirubin and study of its binding interaction with HSA, which regulated its concentration in plasma. The poly(methyl methacrylate) (PMMA) multichannel chip was fabricated by CO2 laser ablation and bonded with a fused-silica separation capillary for CE/FA separation with UV detection. The chip was designed to allow a complete assay of four electrophoretic runs using preconditioned channels to speed up the determination of free bilirubin and to deliver quick results for bedside monitoring. Under optimized conditions, the linear working range for free bilirubin was from 10 to 200 micromol with RSDs from 2.1 to 5.0% for n=3, and the LOD at 9 micromol for S/N=3. From a binding study between bilirubin and HSA under FA condition, the second binding constant for bilirubin-HSA was determined as 1.07x10(5) L/mol and the number of binding sites per HSA as 3.46. The results enabled the calculation of free bilirubin for jaundiced infants based on the clinically significant level of total bilirubin, producing a range of 118.3-119.4 micromol/L. The developed method is shown to meet the clinical requirement with additional margin of protection to detect the early rising level of free bilirubin prior to jaundice condition. The low-cost microchip CE/FA device is shown to produce quick results with high potential to deliver a suitable bed-side monitoring method for bilirubin management in neonates.     

Study on the interaction of tamiflu and oseltamivir carboxylate with human serum albumin

Oseltamivir phosphate (OP; tamiflu) is an antiviral pro-drug, which is hydrolyzed hepatically to the active metabolite oseltamivir carboxylate (OC). It is the first orally neuraminidase inhibitor that was used in the treatment and prophylaxis of influenza virus A and B infection. Human serum albumin (HSA) is the most abundant of the proteins in the blood plasma and is major transporter for delivering several drugs in vivo. This study was designed to examine the interaction of HSA with oseltamivir phosphate (OP) and oseltamivir carboxylate (OC) in aqueous solution at physiological conditions, using a constant protein concentration and various drug contents. FTIR, UV-Vis spectroscopic methods were used to determine the drugs binding mode, the binding constant and the effects of drug complexation on protein secondary structure. Structural analysis showed that OP and OC bind HSA via polypeptide polar groups with overall binding constants of K(OP-HSA)=3.86(± 1.05)× 10(3)M(-1) and K(OC-HSA)=1.5(±0.45) × 10(2)M(-1). The alterations of protein secondary structure are attributed to a partial destabilization of HSA on drug complexation. The protein secondary structure showed no major alterations at low drugs concentrations (50 μM), whereas at higher content (1mM), decrease of α-helix from 58% (free HSA) to 38% (OP-HSA)-48% (OC-HSA), decrease of random coil from 15% (free HSA) to 2% (OP-HSA)-3% (OC-HSA), increase of β-sheet from 6% (free HSA) to 20% (OC-HSA)-29% (OP-HSA) and turn from 8% (free HSA) to 17% (OC-HSA)-19% (OP-HSA) occurred in the drug-HSA complexes. These observations indicated that low drug content induced protein stabilization, whereas at high drug concentration, a partial protein destabilization occurred in these drug-HSA complexes.     

Capillary zone electrophoresis for determination of carbohydrate-deficient transferrin in human serum

Carbohydrate-deficient transferrin (CDT) is the most specific marker for diagnosis of chronic excessive alcohol consumption and includes the serum transferrin (Tf) isoforms with two or less sialic acid residues (di-, mono-, and asialo-Tf). To monitor serum CDT, we developed a capillary zone electrophoresis (CZE) method based on the dynamic capillary coating with diethylenetriamine (DETA). The separation was performed in a bare fused-silica capillary (50 microm ID, 57 cm in length), applying a voltage of 25 kV and a temperature of 40 degrees C. Using a 100 mmol/L borate buffer, pH 8.4 with 3 mmol/L DETA, the Tf isoforms (asialo- to pentasialo-Tf) were resolved within 16 min. Enzymatic cleavage of sialic acid residues with neuraminidase and immunosubtraction were used to identify CDT isoforms. The relative amount of CDT expressed as area % of disialo-Tf isoform related to the area of tetrasialo-Tf in 50 healthy donors (24 males and 26 females; aged 25-50 years) was 3.15 +/- 0.76% (mean +/- SD). The comparison between CDT values obtained by this CZE procedure and the "Axis-Shield %CDT" kit gave r = 0.644, p < 0.001 (n = 290). This easy to use and inexpensive CZE procedure could be an ideal tool to investigate CDT proteins for clinical or forensic purposes.     

荧光法研究药物分子与人血清白蛋白的结合作用

本文应用荧光光谱和能量转移技术首次研究了心血管病药物盐酸地尔硫卓、盐酸川芎嗪和甘草酸三种药物分子与人血清白蛋白的结合作用。研究结果表明, 盐酸川芎嗪和盐酸地尔硫卓在溶液中与白蛋白形成缔合物, 荧光猝灭机理符合静态机制, 缔合物的稳定常数分别为: 盐酸川芎嗪Ks=1.12×10^4(mol/L)^-^1(25℃),Ks=6.95×10^3 (mol/L)^-^1(40℃); 盐酸地尔硫卓Ks=4.71×10^2(mol/L)^-^1(25℃), Ks=3.00×10^2(mol/L)^-^1(40℃)。甘草酸与白蛋白的作用符合动态猝灭机理, 动态猝灭常数为Kd=4.76×10^(mol/L)^-^1(25℃), Kd=6.19×10^2(mol/L)^-^1(40℃)。基于Forster 偶极-偶极无辐射能量转移机理确定了药物分子盐酸川芎嗪在人血清白蛋白中与第214位色氨酸残基之间的距离R=1.76nm(25℃), R=1.80nm(40℃)。     

A preliminary evaluation of serum proteins by capillary electrophoresis

We evaluated the 5-band Serum Proteins by Capillary Electrophoresis kit (Bio-Rad Laboratories, Hercules, CA, U.S.A.) on the BioFocus 2000 CE (Bio-Rad) against conventional agarose gel electrophoresis (AGE) (Helena Laboratories, Beaumont, TX, U.S.A.). Serum from 60 patients was initially screened by AGE and divided into three groups: 1) normal electrophoretic pattern (n = 36, mean total protein 67.7 g/L), 2) monoclonal/oligoclonal gammopathy (n = 14, mean total protein 78.8 g/L), and 3) polyclonal gammopathy (n = 10, mean total protein 77.4 g/L). These samples were concurrently analyzed on the BioFocus 2000. Intraassay and interassay CVs for the five fractions for a normal sample were 0.17-1.44% and 0.42-9.11%, respectively, and 0.21-3.37% and 0.29-3.61%, respectively, for a sample with monoclonal gammopathy. Correlation coefficients for albumin and the albumin/globulin (A/G) ratio were 0.8891 (albumin range 17-93 g/L) and 0.8276 (A/G ratio range 0.39-7.81), respectively. The A/G ratio alone could not discriminate between the three groups. Capillary zone electrophoresis (CZE) correctly identified 33 of 36 samples in the normal group, and 22 of 24 samples in the other two groups, giving a clinical sensitivity and specificity of 91.7%. Our preliminary evaluation shows that protein separation by CZE is a simple, rapid, and automated alternative to conventional AGE.     

Study on the protein binding of ketoprofen using capillary electrophoresis frontal analysis compared with liquid chromatography frontal analysis

A method of capillary electrophoresis frontal analysis (CEFA) is developed for the first time to study the binding of ketoprofen to human serum albumin (HSA) and compared with high-performance liquid chromatography frontal analysis (LCFA). The separation is performed in an uncoated fused-silica capillary (60-cm x 75- micro m i.d., 50-cm effective length) with a phosphate buffer (pH 7.4, ionic strength of 0.17M) as the running buffer. The applied voltage is 13 kV and the detection is set at 254 nm. A trapezoidal peak of the unbound ketoprofen appears after HSA elution in the electropherogram. The plateau height of the peak is employed to determine the unbound concentration of ketoprofen in the HSA equilibrated sample solution. The CEFA method provides the advantages of small sample injection volume and rapidity and the disadvantage of low sensitivity compared with LCFA. CEFA is applicable to the binding parameter estimation of ketoprofen to the secondary binding site; an association constant (K(2)) of 0.24 x 10(6)M(-1) and the number for the binding site per molecule HSA of 2.54 is estimated. In contrast, LCFA measures parameters for both primary and secondary sites, which are 1.05 x 10(6)M(-1) and 0.94 for K(1) and n(1), respectively, and 0.12 x 10(6)M(-1) and 3.16 for K(2) and n(2), respectively. It is found that ketoprofen binds mainly at the primary site at a molecular ratio of ketoprofen versus HSA lower than 0.75, and the binding at the secondary site occurs at a higher ratio.