PURIFICATION OF L-METHIONINE AND N-ACETYL-D-METHIONINE FROM THE MIXTURE OF ENZYMATICALLY DEACYLATED N-ACETYL-DL-METHIONINE

N-acetyl-D-methionine, AaAc and the remams of N-acetyl-L-methionme dramatically.affect the purification of L-methionine when purified from the mixture of en.“ymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and tile ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.     

离子交换法从N-Ac-DL-Methionine的酶拆分液中分离制备L-Methionine和N-Ac-D-Methionine

依据N-Ac-DL-Methionine的酶拆分液及其组分特有的性质，采用强酸型阳离子交换柱成功地将拆分液中各组分进行分组．分析了流出液的pH和L-Met浓度的变化规律和原因；讨论并确定了柱的交换容量与所加拆分液中钠的含量的最佳比值范围．本实验方法不仅可以获得L-Met，且兼得N-Ac-D-Met，二者的收率在小试中分别达到85％以上75％左右．     

Isolation and purification of an aminoacylase fromAspergillus oryzae

An aminoacylase (EC 3.5.1.14) has been isolated from a surface culture of the fungusAspergillus oryzae (amilorizin P10X) with a 764-fold degree of purification, an activity yield of 32.7%, and a specific activity in relation to the hydrolysis of N-acetyl-D,L-methionine of 99.3 a.u./o.u. The scheme of the purification of the aminoacylase fromAspergillus oryzae includes: extraction at pH 6.7, precipitation with ammonium sulfate (30 and 80% saturation), gel filtration on Acrilex P-150 (pH 7.5), ion-exchange chromatography on amino-Silochrom Cx-1,5 (mean pore radius 790 Å); the sorption of the enzyme takes place at pH 6.2 and elution with 0.05 M borate buffer, pH 8.0; ion-exchange chromatography on AH-Sepharose 4B at pH 8.0, with elution by a stepwise increase in the concentration of sodium chloride to 0.25 M; and, finally, gel filtration on Sephadex G-200 (pH 8.0). According to the results of disk electrophoresis in 7.5% polyacrylamide gel in a Tris-glycine systems of buffers with a separation pH of 8.9 in the presence of Co²⁺ ions (10^–5 M) of theAspergillus oryzae aminoacylase, two components possessing enzymatic activity were detected, with R_f 0.53 (major component) and R_f 0.63 (minor component).All-Union Scientific-Research Institute for the Genetics and Breeding of Industrial Microorganisms, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 619–624, September–October, 1983.     

Preparative isolation of angiotensin-converting enzyme from human lung.

Angiotensin-converting enzyme from human lung was purified to apparent homogeneity using a five-step purification procedure consisting of ammonium sulfate precipitation, ion-exchange chromatography on DEAE Sephadex A-50, gel permeation on Sephadex G-200, chromatofocusing on a polybuffer exchange (PBE 94) column and high-performance liquid chromatographic gel permeation on a Bio-Sil TSK-250 column. This procedure gave an approximately 700-fold purification with a 20% yield compared to a 550-fold purification and a 1% yield with an affinity chromatography-based procedure. The 20-fold greater yield of the five-step procedure offers a major advantage for preparative use in the structural characterization of angiotensin-converting enzyme.     

大孔离子交换树脂分离纯化玻璃酸的研究

本文选用了四种离子交换树脂进行分离纯化玻璃酸的研究，结果表明，采用 Ｄ３１５大孔离子交换树脂，以去离子水为淋洗液， ０．６ｍｏｌ／Ｌ ＮａＣｌ溶液为洗脱液，纯化效果较佳。纯化产品杂蛋白含量≤０．３％，回收率达７１．１％，粘均分子量大于９６万。     

大孔离子交换树脂分离纯化玻璃酸的研究

本文选用了四种离子交换树脂进行分离纯化玻璃酸的研究。结果采用Ｄ３１５大孔离子交换树脂，以去离子水为淋洗液，０．６ｍｏｌ／Ｌ ＮａＣｌ溶液为洗脱液，纯化效果较佳，纯化产品杂蛋白含量≤０．３％，回收率达７１．１％，粘均分子量大于９６万。     

Specific Features of Ion-Exchange Zinc(II) Extraction from Washing Water of Zinc Plating

Specific features of ion-exchange purification of washing water formed in zinc plating in an alkaline medium are considered. The parameters of extraction of zinc ions and regeneration of ion-exchange resins are optimized.     

Application of preparative reversed-phase high-performance liquid chromatography to the isolation of insulin-like growth factor II from human serum

Substantially purified insulin-like growth factor II (IGF-II) was prepared from human serum. Initial enrichment using ion-exchange chromatography on DEAE Sephadex A50, followed by gel permeation chromatography on Sephadex G-75 in 1% formic acid produced material suitable for application to a preparative reversed-phase high-performance liquid chromatographic (HPLC) column containing LiChroprep RP-18. The latter step gave about 90-fold purification with a recovery of about 70% IGF-II bio-activity. Finally, a small reversed-phase HPLC column achieved a 17-fold purification with similar yield of activity. Overall, the four steps gave IGF-II of about 90% purity in yield of 12%.     

Chromatographic purification of human α1 proteinase inhibitor from dissolved Cohn fraction IV-1 paste

A novel chromatographic process for purification of α₁ proteinase inhibitor (α₁-PI) from Cohn fraction IV-1 paste is described. This process has been successfully scaled up to 50-l columns. It involves DEAE chromatography, sulfopropyl (S) cation chromatography, tri-n-butyl phosphate (TNBP)–cholate treatment, a second S cation chromatography, freeze–drying and dry-heat. The process has been optimized for purity, yield, lipid removal, chemical usage and water consumption. Filtration after TNBP–cholate treatment plays a key role in ensuring a low lipid content in the final product. Pre-equilibration with high salt buffer is necessary to reduce the water consumption significantly during the ion-exchange chromatography equilibration step. The final product is approximately 95% pure by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, with a 64% to 70% yield from IV-1 paste.     

Model-based optimization of a preparative ion-exchange step for antibody purification

A method using a model-based approach to design and optimize an ion-exchange step in a protein purification process is proposed for the separation of IgG from a mixture containing IgG, BSA and myoglobin. The method consists of three steps. In the first step, the model is calibrated against carefully designed experiments. The chromatographic model describes the convective and dispersive flow in the column, the diffusion in the adsorbent particles, and the protein adsorption using Langmuir kinetics with mobile phase modulators (MPM). In the second step, the model is validated against a validation experiment and analyzed. In the third and final step, the operating conditions are optimized. In the optimization step, the loading volume and the elution gradient are optimized with regard to the most important costs: the fixed costs and the feed cost. The optimization is achieved by maximizing the objective functions productivity (i.e. the production rate for a given amount of stationary phase) and product yield (i.e. the fraction of IgG recovered in the product stream). All optimization is conducted under the constraint of 99% purity of the IgG. The model calibration and the analysis show that this purification step is determined mainly by the kinetics, although as large a protein as IgG is used in the study. The two different optima resulting from this study are a productivity of 2.7 g IgG/(s m3) stationary phase and a yield of 90%. This model-based approach also gives information of the robustness of the chosen operating conditions. It is shown that the bead diameter could only be increased from 15 microm to 35 microm with maximum productivity and a 99% purity constraint due to increased diffusion hindrance in larger beads.     

PURIFICATION OF FLAVONES OF GINKGO LEAVES BY ADSORPTION HZ-841 RESIN

The purification process of total flavones of ginkgo leaves by resin HZ-841 from ethanol extract was studied. First, the total flavone was extracted from the clef aired powder of ginkgo Lbiloba leaves. Effects of solvents and operation conditions were examined to get a relative high yield and purity in this step. The crude extract was further purified by resin HZ-841. Both adsorption and elution process were studied to obtain an optimized conditions, i.e., pH, flow rate, concentration. A yellow powder was obtained, of which 37.3% was flavones, obviously higher than the basic international standard of 24%.     

PURIFICATION OF FLAVONES OF GINKGO LEAVES BY ADSORPTION HZ-841 RESIN

The extraction of dry ginkgo biloba L. leaves is a mixture of some effective agents like flavones and lactones, which have therapeutic activities of peripheral vasoregulation, PAF (platelet aggregation factor) antagonism and prevention of membrane damage caused by free radicals, etc. Thus broad application prospect in the field of sanitarian product and cosmetics is expected [1]. The total flavonoid can be extracted in distilled water or in organic solvents, usually methanol, ethanol, or ace…     

离子交换色谱法分离纯化鸡卵黄免疫球蛋白

建立了高效、经济、大规模获得鸡卵黄免疫球蛋白(IgY)的生产方法。在对传统的水稀释法改良的基础上,结合聚乙二醇沉淀与离子交换色谱进行IgY的分离纯化。结果显示,用8倍无菌水稀释蛋黄液,用0.1 mol/L HCl调节pH为5.2,在4 ℃下静置8 h,于5000×g力离心可得上清粗IgY液,经测定回收率可达93.47%。然后用6%聚乙二醇沉淀后经DEAE-Toyopearl 650 M离子交换纯化,最佳的纯化条件: 0.05 mol/L磷酸盐缓冲液(PBS, pH 7)平衡上样,0.075 mol/L PBS(pH 7)洗脱。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析结果显示所得的IgY的纯度为95.02%,活性保持率高达73.77%。本研究弥补了传统分离方法不能同时达到高纯度和高回收率的缺点,且可用于大规模生产。     

Ni(II)-based immobilized metal ion affinity chromatography of recombinant human prolactin from periplasmic Escherichia coli extracts

A novel, two-step preparative technique is described for the purification of authentic recombinant human prolactin (rhPRL) secreted into the periplasm of transformed Escherichia coli cells. The first step is based on immobilized metal ion affinity chromatography of periplasmic extract, using Ni(II) as a relatively specific ligand for hPRL in this system. It gives superior resolution and yield than established ion-exchange chromatography. Size-exclusion chromatography is used for further purification to >99.5% purity. The methodology is reproducible, leading to 77% recovery. Identity and purity of the rhPRL were demonstrated using sodium dodecylsulphate-polyacrylamide electrophoresis, isoelectric focusing, mass spectrometry (matrix-assisted laser desorption ionization time-of-flight), radioimmunoassay, RP-HPLC and high-performance size-exclusion chromatography. In the Nb2 bioassay, the hormone showed a bioactivity of 40.9 IU/mg.     

Purification of the glycoprotein glucose oxidase from Penicillium amagasakiense by high-performance liquid chromatography

Fast protein liquid chromatography (FPLC) in combination with ion-exchange chromatography on a Mono Q column was used to purify glucose oxidase from Penicillium amagasakiense to homogeneity. Purification was performed with a mixed pH and salt gradient, with 20 mM phosphate buffer (pH 8.5) as starting buffer (A) and 50 mM acetate buffer (pH 3.6) with 0.1 M NaCl as elution buffer (B). Elution conditions were optimized to permit the simultaneous purification and separation of the glucose oxidase isoforms. Three peaks, each consisting of 1-2 isoforms and exhibiting a homogeneous titration curve profile, were resolved with a very flat linear gradient of 5.0-5.1% B in 40 ml. Three more peaks, each consisting of several isoforms, were eluted at 10%, 30% and 100% B. Optimization of the elution conditions and separation of the glucose oxidase isoforms was only possible because of the rapidity of each purification step and the high resolution provided by FPLC and Mono Q.     

D/L扁桃酸的合成研究

对D／L扁桃酸的合成工艺进行了优化,尤其在溶剂的选择与回收,二氯化物的制备以及产品的纯化与提取等方面作了有效的改进,收率与纯度有很大改善,分别达到80％和99．4％。     

The isolation of erysimoside

Summary 1. The conditions for the purification of a crude extract from resinous substances and sugars by organic solvents and from ballast substances by ion-exchange purification, and also the extraction of erysimoside from the purified aqueous solution, have been investigated.2. The yield of erysimoside by the method described has been increased to 2% of the weight of the seeds.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 22–25, January–February, 1975.     

Determination of227Ac in environmental samples by ion-exchange and alpha spectrometry

A new method of²²⁷Ac determination is based on total sample decomposition, followed by preconcentration as oxalate and hydroxides, and purification from thorium isotopes and rare earths on ion-exchange columns with nitric acid. The actinium is electroplated on stainless-steel discs with near 100% yield from a water/propanol medium and measured by alpha spectrometry.²²⁵Ac is used as a yield monitor. An immediate first count gives overall tracer recovery (typically around 80%). A second count two months later gives a sensitive measure of²²⁷Ac through its decay products at 5.5–6.1 MeV. Analysis of reference samples gave satisfactory results.     

天然植物中生物碱的提取及树脂法在其纯化中的应用

总结了近期提取和分离纯化方法在天然植物中生物碱类有效成分研究中的应用,特别是对于吸附树脂法在生物碱纯化中的应用进行了系统综述,归纳了具有不同结构的大孔吸附树脂、凝胶型离子交换树脂和大孔型离子交换树脂对生物碱纯化效果的影响规律,进而为高效、高选择性纯化生物碱的专用吸附树脂结构设计和应用提供了可借鉴的研究思路.     

Analysis, purification and properties of a 50,000-dalton membrane-associated phosphoprotein from human platelets

Recently, the development of a monospecific antiserum against a 46,000/50,000-dalton membrane protein from human platelets which was stoichiometrically and reversibly phosphorylated in intact human platelets in response to vasodilators was reported. Using this antiserum, the subcellular distribution and the purification of this vasodilator-stimulated phosphoprotein (VASP) from human platelets has now been analysed. The VASP of human platelets is primarily a membrane-associated protein and can be purified to apparent homogeneity by salt extraction and sequential ion-exchange and dye-ligand chromatography with a purification factor of 1200 and a yield of 13%. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing and non-reducing conditions indicated that purified monomers of this VASP are linked by interchain disulphide bonding.