强阴离子交换色谱结合分子排阻色谱纯化血清中免疫球蛋白和白蛋白

动物血清中免疫球蛋白和白蛋白的等电点分别约为7.8和4.8,根据它们等电点的较大差别,利用Q SepharoseTM-XL强阴离子交换色谱结合分子排阻色谱同时分离纯化这2种蛋白。以0.02 mol/L pH 8.0的Tris-HCl缓冲液平衡离子交换色谱柱并将已稀释10倍的高免疫的兔血清上样,采用pH分段洗脱。在pH 6.0时以0.3 mL/min低流速洗脱得到高纯度的免疫球蛋白,继续在pH 4.0时洗脱,再辅以Sephadex G-75分子排阻色谱可获得纯度大于95%的白蛋白。对纯化后的蛋白进行活性检测,证明所纯化的免疫球蛋白和白蛋白都保持正常的生物活性。蛋白质含量测定说明免疫球蛋白的纯化回收率达到95%以上,而白蛋白的纯化回收率大于90%。该法简便快速,可同时从动物血清中纯化出保持生物活性的免疫球蛋白和白蛋白,纯化效率高。     

动力学因素对液相色谱分离整体蛋白的影响

依据液相色谱分离整体蛋白的效果与色谱柱柱长基本无关的事实,研究了动力学因素对疏水相互作用色谱(HIC)分离整体蛋白的影响。首次提出了用于线性梯度洗脱条件下蛋白分离的“条件板高”(H)概念,并将其用于动力学因素对分离整体蛋白的影响的表征。分别用常用的色谱柱和色谱饼对标准蛋白进行了分离,绘制了类似于van Deemter的“条件板高”对流动相线速(u)的曲线图。发现对应于色谱柱最低“条件板高”的适合线速约为色谱饼的1/5～1/15,且色谱饼的适合线速范围也较色谱柱宽得多。据此,用装填有HIC填料的色谱饼(10 mm×20 mm i.d.)在12 min内便可完全分离7种标准蛋白。还用装填有HIC填料的色谱饼对重组人粒细胞集落刺激因子(rhG-CSF)进行了复性并同时纯化,在50 min内,仅用一步色谱法就可获得纯度≥97%的rhG-CSF,其质量回收率为39%,比活＞1×108 IU/mg。可以预计,装填极细颗粒的刚性色谱填料的色谱饼可在高负荷条件下进行整体蛋白的高速和高分离度的分离、纯化并同时复性,达到“三高”。     

快速弱阴离子交换无孔聚合物固定相的制及用于蛋白质的高效液相色谱分离

将粒径为3.0 μm无孔单分散亲水性交联聚甲基丙烯酸环氧丙酯树脂(PGMA/EDMA)的表面经不同的化学方法改性,制备了两种不同配基的弱阴离子交换(WAX-Ⅰ和WAX-Ⅱ)色谱填料.在同等色谱条件下,比较了两种填料对蛋白质的分离性能,发现WAX-Ⅰ型填料分离性能优于WAX-Ⅱ.详细考察了WAX-Ⅰ型弱阴离子交换色谱填料流动相pH值、流速及有机溶剂等对蛋白质保留的影响.实验结果表明,当流动相流速为3mL/min时,4种标准蛋白可在2 min内基线快速分离,蛋白质的保留符合阴离子交换色谱规律.该填料可以用于生物工程产品的快速分离和纯化.     

高效液相色谱-同位素稀释质谱法定量分析人生长激素

建立了人生长激素( hGH)纯化分析和高效液相色谱( HPLC)与同位素稀释质谱( IDMS)联用高准确度绝对定量方法。采用快速蛋白液相色谱来分离纯化hGH,以傅里叶变换离子回旋共振质谱仪( FTICR-MS)准确地测定蛋白质的分子质量。纯化的hGH经酸水解后,采用KINETEX C18色谱柱为分析柱,以水(含0.1%三氟乙酸)和乙腈为流动相,等梯度分离,流速0.2 mL/min,温度40℃,采用电喷雾正离子模式进行电离,选择多反应监测模式进行检测,内标法定量分析。结果表明,FTICR-MS所测得的分子量实测值与理论值仅相差0.31 Da,脯氨酸、缬氨酸和苯丙氨酸在液相条件下5 min内达到基线分离,在最优条件下,hGH含量测定结果为186.80 mg/g,相对标准偏差为0.52%。利用本方法参加国际比对,比对结果与参考值等效一致。本方法具有简易、实用的特点,并且准确可靠,可作为hGH纯品标准物质的定值方法,为hGH的日常检测提供参考。     

某些酚类的高温液相色谱行为

建立了高温液相色谱系统,在高温条件下,采用甲醇-水作为流动相,在Polymerx RP-1聚合物(PSDVB)色谱柱上考察了6种酚类样品的色谱行为.实验条件:温度40～160 ℃,流速0.2～5.5 mL/min,流动相中甲醇浓度范围40%～80%.考察了温度、流速和流动相组成对酚类样品的保留、分辨、柱效和系统压力的影响,探讨了酚类样品在聚合物柱上的热力学行为.温度升高2.35℃大约相当于流动相中甲醇浓度增加1%,可以通过改变色谱柱温度调节样品保留和改变选择性.柱温升高,降低了流动相的粘度,允许在高温条件下使用较高的流速实现快速分离.在160℃、V(甲醇):V(水)=40:60,为流动相和3 mL/min流速条件下,可于2.5 min内实现6种酚类的完全分离.     

硅胶柱色谱结合高速逆流色谱法分离纯化荷花中黄酮类化合物

采用硅胶柱色谱结合高速逆流色谱法分离纯化了荷花中3种黄酮类化合物。荷花粗提物先经过硅胶柱色谱初步分离,得到黄酮含量高的组分,再经过高速逆流色谱分离,以乙酸乙酯-乙醇-水-乙酸(4:1:5:0.025, v/v/v/v)为两相溶剂系统,上相为固定相,下相为流动相,在主机转速800 r/min、流速2.0 mL/min、检测波长254 nm条件下,从150 mg样品中一次性分离制备得到6.1 mg槲皮素-3-O-β-D-葡萄糖醛酸苷(I), 14.8 mg杨梅素-3-O-β-D-葡萄糖苷(II)和20.2 mg紫云英苷(III),经高效液相色谱检测其纯度分别为97.0%、95.4%、96.3%,并通过质谱和核磁共振氢谱、碳谱鉴定各化合物的结构。该方法简便、快速、节省溶剂,可以对荷花中的黄酮类化合物进行快速有效的分离纯化,具有较好的实用价值,为荷花资源的进一步开发应用提供了参考依据。     

一种转基因猪血中重组人血清白蛋白分离纯化新方法

基因工程技术已经成为研究和生产重组人血清白蛋白(rHSA)替代人血清白蛋白(HSA)的重点技术,而白蛋白的纯化则是该技术的关键。本文主要介绍了从转基因猪血中纯化rHSA的一种新方法,即热乙醇沉淀与多级色谱分离相结合的rHSA纯化方法。热乙醇沉淀法可从猪血浆中获得rHSA粗提取液,此时rHSA的纯度可达69.5%,回收率达51.3%。进一步采用多级色谱分离法,即阴离子交换色谱和反相色谱法进一步纯化,得到rHSA的最终纯度约为100.0%,总回收率为41.1%。该方法为从转基因猪血浆中大规模纯化用于临床和生化研究的高纯度rHSA提供可能,同时也为rHSA替代HSA奠定了基础。     

反相液相色谱对多肽的分离、纯化与制备

用反相高效液相色谱（RPLC）对两种化学合成多肽－－32肽和21肽进行了分离、纯化和制备。在用分析型RPLC色谱柱对多肽样品的制备过程中，对其进样量和洗脱梯度进行了选择。每次进样量为5mg，在最优化色谱条件下，用RPLC一步就可对21肽进行分离纯化，其纯度达到98.6%。而32肽由于样品组分更加复杂，RPLC一步纯化后其纯度仅有80％。通过对色谱分离条件的再次优化，对32肽进行二次分离纯化，纯度达杂，RPLC一步纯化后其纯度仅有80％。通过对色谱分离条件的再次优化，对32肽进行二次分离纯化，纯度达到96.4%。在其最优化条件下，通过多次样品收集和冷冻干燥，分别制备了高纯度的21肽和32肽各100mg。     

全二维液相色谱的初步构建及其在山羊血清分离中的应用

以GFC/RP模式构建全二维液相色谱系统,第一维凝胶过滤色谱柱使用ShodexProteinKW 802. 5(300mm×8mmi.d. ),以0. 2mol/LNaH2PO4 (pH7. 0)的流动相在0. 15mL/min的流速下等度洗脱,第二维反相色谱柱使用HypersilBDSC18 (35mm×4. 6mmi.d. ),在3mL/min的流速下梯度洗脱。采用平行柱交替分析的形式作切换接口, 2. 5min切换一次,两个反相柱交替富集、分析第一维洗脱产物。以5个标准蛋白混合物的分离评价该系统,在单独一维模式中不能分离的样品在全二维液相色谱中得到了较好的分离,二维系统的总峰容量为225。与一维色谱相比,系统的总峰容量、分辨率得到较大提高。并用于山羊血清的纯化分析,对一维分离中的重合谱峰进行验证,对制备纯化有一定的实际意义。     

快速弱阴离子交换无孔聚合物固定相的制备及用于蛋白质的高效液相色谱分离

将粒径为3.0μm无孔单分散亲水性交联聚甲基丙烯酸环氧丙酯树脂(PGMA/EDMA)的表面经不同的化学方法改性,制备了两种不同配基的弱阴离子交换(WAX-Ⅰ和WAX-Ⅱ)色谱填料。在同等色谱条件下,比较了两种填料对蛋白质的分离性能,发现WAX-Ⅰ型填料分离性能优于WAX-Ⅱ。详细考察了WAX-Ⅰ型弱阴离子交换色谱填料流动相pH值、流速及有机溶剂等对蛋白质保留的影响。实验结果表明,当流动相流速为3mL/min时,4种标准蛋白可在2min内基线快速分离,蛋白质的保留符合阴离子交换色谱规律。该填料可以用于生物工程产品的快速分离和纯化。     

半制备型柱与饼性能的比较

 通过比较具有相同柱几何体积的半制备柱和饼的性能 ,发现在同样的条件下 ,用液相方法分离生物大分子时 ,在分离效率和蛋白活性回收方面 ,饼和柱的差异不大 ;由于饼中的填料较柱中的装填更为紧密和均匀 ,当流动相流速增加时 ,饼不仅反向压力上升慢 ,而且质量和体积负载也比柱高。该结果表明使用饼的分离不仅具有可与高效液相 (HPLC)媲美的分离效率 ,而且还具有中、低压分离的高柱负载 ,这有利于蛋白保持高的生物活性 ,为饼的工业化应用奠定了基础。     

Purification and analysis of mono‐PEGylated HSA by hydrophobic interaction membrane chromatography

We discuss the purification of mono‐PEGylated HSA by hydrophobic interaction membrane chromatography. The hydrophobicity difference between the different fractionated species was induced by the addition of a lyotropic salt that caused phase transition of PEG (hydrophilic under normal condition) to a mildly hydrophobic form. The HSA PEGylation reaction mixture was mixed with lyotropic salt and passed through a stack of hydrophilized polyvinylidene fluoride membrane discs. Unmodified HSA was obtained in the flow through, while the PEGylated forms of the protein bound to the membrane and could be eluted by reducing the salt concentration. Among the three major PEGylated forms of HSA present in the feed (i.e. mono–, di–, and tri–), mono‐PEGylated HSA was eluted first and could be resolved from the others. The purified material was analyzed by SDS‐PAGE, dynamic light scattering, and SEC combined with multi‐angle light scattering. All these analytical techniques indicated the presence of species that has a molar mass consistent with mono‐PEGylated HSA. A scaled‐down version of the membrane chromatographic methods could be used for the rapid and sensitive analysis of PEGylated proteins.     

Novel affinity separations based on perfluorocarbon emulsions. Use of a perfluorocarbon affinity emulsion for the purification of human serum albumin from blood plasma in a fluidised bed.

A perfluorocarbon affinity emulsion has been generated by homogenisation of a saturated perfluorocarbon oil with a polymeric fluorosurfactant based on poly(vinyl alcohol) (relative molecular mass 9000-10,000) previously derivatised with the triazine dye CI Reactive Blue 4. This affinity emulsion has subsequently been cross-linked in situ and used in a fluidised bed for the purification of human serum albumin (HSA) from blood plasma. HSA was quantitatively recovered in a semi-continuous fashion from plasma at an average purity of 90 +/- 3.3%. The albumin binding capacity of the emulsion has been shown to be 0.59 mg/ml by frontal analysis corresponding to a mol/mol ligand usage of 13.5%. In all regards, when used in a fluidised bed, the emulsions have been shown to behave as a normal chromatographic material. They are stable under operational conditions with no coalescence being observed for periods greater than 1 year. These novel liquid affinity supports present an exciting opportunity to develop a range of unit operations for the continuous purification of proteins.     

分离尿激酶的亲和色谱填料的制备

 合成了分别以 Sepharose和聚甲基丙烯酸环氧丙酯为基质、对氨基苯甲脒为配基的分离尿激酶的两种亲和色谱填料 ,并用于尿激酶粗品的直接纯化 ,活性回收率分别为 1 0 8.3 %和 43 .4% ,比活提高倍数分别为 9.0 6倍和 3 6.9倍。     

Electrochemical Study on the Interaction of Protein with Bromothymol Blue and Its Analytical Application

The interaction of bromothymol blue（BB） with human serum albumin（HSA） was studied by electrochemical techniques and a sensitive method for proteins assay was developed. When BB interacted with HSA, the voltammetric peak current value of BB decreased linearly with the concentration of HSA in a range of 1.0--40.0 mg/L, and the peak potential shifted negatively. Based on the results, a sensitive assay method for proteins, such as HSA, bovine serum albumin（BSA）, and egg albumin etc. was established. This method was further applied to determining the HSA in healthy human blood samples, and the results are not significantly different from those obtained by the classic Coomassie Brilliant Blue G-250 spectrophotometic method. The detecting conditions of this method were optimized and the interaction mechanism was discussed. The results show that the electrochemical parameters（formal potential E^0, standard rate constant of the electrode reaction ks, parameter of kinetic nα） of BB have no obvious changes before and after the interaction, which indicate that BB can interact with HSA, forming an electrochemical non-active complex. The equilibrium constant（βs） and the binding ratio（m） for this complex were calculated. The m is 4 and βs is 1.41 × 10^19. This method is fast, simple, highly sensitive, and has good selectivity, which can be used in clinical measurements.     

用于变性蛋白质复性及同时纯化的简易型色谱柱的研制及其应用

研制出一种简易型色谱柱并通过装填大颗粒的疏水色谱填料对色谱柱的性能进行了考察,该柱的外形和操作如同传统的液相色谱柱,但它却在生物大分子分离方面有着和高效液相色谱相似的分辨率。另外,只要给该柱装填合适的固定相,比如疏水相互作用色谱固定相,便可用于蛋白质的复性及同时纯化。实验考察了该色谱柱的结构、操作和性能,包括柱压、柱寿命及对蛋白质的分辨率等。以溶菌酶为模型蛋白质,实验测得其在初始浓度为50.0 g/L时的质量回收率和活性回收率分别为(96.6±1.3)%和(101.1±6.0)%。这种简易型色谱柱价格低廉     

Application of monoliths for plasmid DNA purification development and transfer to production

The demand of high-purity plasmid DNA (pDNA) for gene-therapy and genetic vaccination is still increasing. For the large scale production of pharmaceutical grade plasmids generic and economic purification processes are needed. Most of the current processes for pDNA production use at least one chromatography step, which always constitutes as the key-step in the purification sequence. Monolithic chromatographic supports are an alternative to conventional supports due to their excellent mass transfer properties and their high binding capacity for pDNA. Anion-exchange chromatography is the most popular chromatography method for plasmid separation, since polynucleotides are negatively charged independent of the buffer conditions. For the implementation of a monolith-based anion exchange step into a pDNA purification process detailed screening experiments were performed. These studies included supports, ligand-types and ligand-densities and optimization of resolution and productivity. For this purpose model plasmids with a size of 4.3 and 6.9 kilo base pairs (kbp) were used. It could be shown, that up-scaling to the production scale using 800 ml CIM Convective Interaction Media radial flow monoliths is possible under low pressure conditions. CIM DEAE was successfully implemented as intermediate step of the cGMP pDNA manufacturing process. Starting from 2001 fermentation aliquots pilot scale purification runs were performed in order to prove scale-up and to predict further up-scaling to 8 1 tube monolithic columns. The analytical results obtained from these runs confirmed suitability for pharmaceutical applications.     

强阴离子色谱法从毕赤酵母培养液中分离纯化重组巴西日圆线虫乙酰胆碱酯酶

提出了一种从基因工程毕赤酵母(Pichia pastoris)培养液中分离纯化重组巴西日圆线虫(Nippostrongylus brasiliensis)乙酰胆碱酯酶(NbAChE)的方法。采用Q-Sepharose Fast Flow强阴离子交换色谱柱对重组NbAChE进行了分离纯化。十二烷基硫酸钠聚丙烯酰胺凝胶电泳分析表明,纯化物的活性峰为单一蛋白质带,其相对分子质量约为66000。该方法的活性回收率为52.6%,纯化因子为3.87;纯化后AChE的比活为 2837 U/mg。结果表明,该法是一种理想的分离纯化重组NbAChE的方法。     

Isolation of tomato pectin methylesterase and polygalacturonase on monolithic columns

An improved cation-exchange chromatographic procedure on Convective Interaction Media (CIM, BIA Separations, Ljubljana, Slovenia) short monolithic methacrylate disk columns was used for the isolation of salt-independent pectin methylesterase (PME; EC 3.1.1.11) isoform and endo-polygalacturonase PG1 (PG, EC 3.2.1.15) from ripe tomato fruit extract after studying the chromatographic conditions including type of disk, binding buffer, pH, eluent composition and different gradients. Between 10 and 20 microg of proteins gave reliable chromatograms. Both carboxymethyl (CM) and sulfonyl (SO3) disks were equally suitable for the fractionation of tomato extract using the new gradient, but only CM disk was appropriate for further purification of the PME and PG fractions, and provided fast and sharp separation of proteins. The isolation of pure PG1 could be achieved only by addition of 20% of acetonitrile to the mobile phase. About 200 microg of proteins were loaded at one chromatographic run at the fractionation and purification. Determination of the molecular weights of the separated proteins showed that dimer of salt-independent PME isoform was formed in concentrated solutions of the enzyme but dissociated upon dilution of the solution. From 6 kg of fresh tomato flesh, 28 mg of purified salt-independent PME, 12.5mg of purified and active PG1 and 4 mg of PG2 fraction contaminated with salt-dependent PME isoform were obtained by means of semi-preparative chromatography on CIM disks.