HSP2 recombinant in BL21 (DE3) pLysS strain was expressed at high level, but had varied in variable conditions from 22 - 370C. After simple steps of processing, HSP2 in soluble form could be purified by ion-exchange chromatography through CM-sepharose on FPLC system
Escherichia coli ; proteins ; isolation & purification

Human serum albumin(HSA) has been used clinically to treat a number of diseases with high dosage. Extremely pure puoduct is required in large-scale production. Plasma-derived HSA(pHSA) has long been produced by precipitation methods. Among them cold ethanol precipitation is dominant. However, chromatographic purification of HSA has been increasingly studied in the last few years. Application of chromatography, especially ionexchange, affinity, and size-exclusion, has opened a new area in the production of pHSA. A new challenge is the purification of recombinant HSA(rHSA). A successful approach involves STREAMLINE expanded bed adsorption to direct capture the target product from the fermentation broth. This novel process eliminates the need to separate the cells by centrifugation or membrane filtration. Ion exchange chromatography and hydrophobic chromatography play a central role in the purification scheme. Integration with other chromatographic techniques such as size-exclusion, metal chelate, and affinity gives improved purification results. Though innovative, the purification of rHSA still needs further improvement and optimization to increase product purity and process recovery.
Humans ; Recombinant Proteins ; isolation & purification ; Serum Albumin ; isolation & purification

In order to improve the stationary phase retention of polar solvent systems and aqueous two-phase systems (ATPSs), we designed a multiple spiral disk assembly for type-J high-speed counter-current chromatography (HSCCC). The stationary phase retention was studied under different elution modes by using two solvent systems that contained 1-butanol-acetic acid-water (4:1:5, V/V/V) and polyethylene glycol (PEG) 1000-K2HPO4-water (12.5:12.5:75, W/W/W). The best retention was obtained in L-I-T, U-O-H, L-I-H three modes by pumping lower mobile phase from inner terminal (I) to outer terminal (O), and upper mobile phase from outer terminal (O) to inner terminal (I) at a relatively high flow rate. Meanwhile, the relationship between retention percentage of the stationary phase (Sf) and various parameters such as flow-rate (F), rotation speed (w) and column temperature (T) was also studied. Sf increased with the increase of w and decreased with the increase of F. Regression analysis showed a linear relationship between Sf and F1/2/w. The influence of T on Sf was not obvious between 20 degrees C and 40 degrees C, lower temperature than 20 degrees C was not suitable for viscous ATPSs. Acceptable resolutions were achieved when it was applied for the separation of dipeptides including Leu-Tyr and Val-Tyr by using 1-butanol-acetic acid-water (4:1:5, V/V/V) solvent system. The proteins including cytochrome C and myoglobin, lysozyme and myoglobin, and fresh chicken egg-white proteins were well separated by 12.5% PEG1000-12.5% K2HPO4-75% water (pH 9.0) and 16% PEG 1000-12.5% K2HPO4-71.5% water (pH 8.0) system.
Countercurrent Distribution ; instrumentation ; methods ; Peptides ; isolation & purification ; Proteins ; isolation & purification

Fusion tags are originally developed to facilitate the purification of recombinant protein from crude extracts. In recent years, the discovery of different tags and the development of fusion strategy make the function of fusion tags diversified. However, there was no a cure-all fusion tag for different applications. We here give an overview of fusion tag technology and the different applications of fusion tags, including the purification, detection and oriented immobilization of recombinant protein, the visualization of bioevent in vivo, the enhancement of the yield of protein, the improvement of the solubility and stability of the expressed protein.
Recombinant Proteins ; chemistry ; isolation & purification ; Solubility

OBJECTIVETo purify the recombinant human cellular repressor of EIA stimulated gene (hCREG)/myc-His glycoprotein and confirm the biological function of hCREG/myc-His which could inhibit the proliferation of human internal thoracic artery smooth muscle cells (HITASY) cultured in vitro.

METHODSThe recombinant hCREG/myc-His protein was purified with Ni-NTA column according to 6 x His affinity chromatographic theory. The recombinant hCREG/myc-His protein was desalted by HiTrap Desalting Column. The effect of recombinant hCREG/myc-His glycoprotein of different concentration (0.5 microg/ml, 1 microg/ml and 2 microg/ml) on proliferation of HITASY cells was studied by flow cytometric analysis and the effect of recombinant protein on proliferation of HITASY cells was confirmed by BrdU incorporation method.

RESULTSThe recombinant hCREG protein was purified with Ni-NTA column according to 6 x His affinity chromatographic theory. The concentration of recombinant hCREG protein which has been concentrated and desalted was determined to be 1.6 mg/ml and the purity of recombinant protein reached 92%. The protein was identified to be glycosylated. The recombinant hCREG protein was identified to inhibit the proliferation of HITASY cells cultured in vitro and the inhibition effect was stronger in low-dosage group than that in high-dosage group by flow cytometric analysis. The proliferation of HITASY cells cultured in vitro with 2 microg/ml recombinant hCREG protein was inhibited significantly compared with that in control group according to the BrdU incorporation result. There was statistical difference among the groups (P < 0.05).

CONCLUSIONThe purification of recombinant hCREG/myc-His glycoprotein with biological activity provides an experiment platform for function study and engineering production of hCREG protein.

Adenoviridae ; Cell Division ; Cells, Cultured ; Glycoproteins ; isolation & purification ; Glycosylation ; Humans ; Recombinant Proteins ; isolation & purification ; metabolism ; Repressor Proteins ; isolation & purification ; metabolism

OBJECTIVETo purify recombinant nuclear protein of Hantaan virus.

METHODSThe recombinant plasmid was transformed into E.coli and induced by IPTG. The expressed protein is a fusion protein with GST and existed in inclusion bodies. The inclusion bodies were processed through denaturation and renaturation and were purified with Glutathione Sepharose 4B affinity chromatography column. Then the purified fusion protein and nuclear protein were examined by sandwich ELISA and Western blot.

RESULTSThe expressed fusion protein was separated from the mixture proteins by the first affinity chromatography. GST was cut from the purified fusion protein with thrombin. The nuclear protein was separated from GST by the second affinity chromatography. The crossed peak represents nuclear protein and the elute peak represents GST. The purified fusion protein and nuclear protein were single band by SDS-PAGE. Both of them had available antigen activity.

CONCLUSIONSPurification of nuclear protein of Hantaan virus with Glutathione Sepharose 4B affinity chromatography is an effective method.

Blotting, Western ; Chromatography, Affinity ; Enzyme-Linked Immunosorbent Assay ; Hantaan virus ; Nuclear Proteins ; analysis ; isolation & purification ; Plasmids ; Recombinant Fusion Proteins ; analysis ; isolation & purification ; Viral Proteins ; analysis ; isolation & purification

Endotoxin removal is essential for the safety of biological products. To remove endotoxin efficiently, we used polymyxin B (PMB) affinity adsorbent to remove endotoxin from protein solutions by static adsorption. We studied the effects of spacer length and ligand density of the affinity adsorbent, pH, salt type and concentration, protein type and concentration, endotoxin concentration, and additive on endotoxin removal and protein recovery. Endotoxin content and protein concentration were determined by test and Lowry assay respectively. The results showed that PMB affinity adsorbent had high capacity, high adsorption speed, high removal efficiency and good reusability. In addition, ligand density, pH, salt concentration and the isoelectric point and hydrophobicity of protein all had remarkable influence on the endotoxin removal. Under the optimal conditions, the recoveries of hemoglobin, human serum albumin and lysozyme were 87.2%, 73.4% and 97.3%, respectively, and the corresponding endotoxin removal rates 99.8%, 97.9% and 99.7%, respectively. This study illustrated the effects of solution conditions on the efficiency of endotoxin removal and protein recovery, and would provide useful reference for the efficient removal of endotoxin from biological products.
Adsorption ; Chromatography, Affinity ; methods ; Drug Contamination ; prevention & control ; Endotoxins ; isolation & purification ; Hemoglobins ; isolation & purification ; Polymyxin B ; chemistry ; Proteins ; isolation & purification ; Pyrogens ; isolation & purification ; Serum Albumin ; isolation & purification ; Solutions

Intein is a part of polypeptide in the premature protein with the capability of self-splicing, which is widely applied in protein purification, protein conjuction, cyclopeptide preparation, protein labeling and biosensor. In this review, we summarized the development of intein used in protein purification, discussed intein-mediated chromatographic and non-chromatographic purification systems, and summarized the researches in manipulating intein cleavage reaction. This work is to provide clues for improvement of intein-mediated protein purification.
Chromatography, Affinity ; Inteins ; Protein Splicing ; Proteins ; isolation & purification

OBJECTIVETo set up a rapid, efficient, reliable and accurate method for separation of Bacteriodes forsythus proteins.

METHODSBacteroides forsythus ATCC43037 cells were harvested by centrifugation, washed in Tris buffer to remove excess medium, and lysed by sonication. The sonicated lysis proteins were extracted step by step with ReadyPrep Sequential Extraction Kit (Bio-Rad). The supernatant of B. forsythus proteins were used for two-dimensional gel electrophoresis. The first dimension IEF (isoelectric focusing) was run with Immobiline DryStrip (pH 3-10) and the second dimension SDS-PAGE was run with Excelgel SDS, gradient 8-18 precast gel and buffer strips. The separated proteins were stained with Coomassie Brilliant Blue and silver staining kit (Plusone Silver Staining Kit, Protein, Pharmacia Biotech).

RESULTS1. The protein spots were clear when sample cups were used in the middle of IPG strip during IEF. 2. B. forsythus proteins were separated clearly by horizontal two-dimensional electrophoresis and most of B. forsythus whole-cell proteins were acidic proteins (P13-7).

CONCLUSIONHorizontal two-dimension electrophoresis is a useful method for separating B. forsythus proteins.

Bacterial Proteins ; isolation & purification ; Bacteroides ; isolation & purification ; Electrophoresis, Gel, Two-Dimensional ; methods

A creatininase produced from a Arthrobacter sp. was purified 145-fold by a series of steps including heat treatment, ammonium sulfate precipitation, DEAE-Cellulose ion-exchange and hydrophobic chromatography. The specific activity of the pure enzyme was 209u/mg. The subunit molecular mass of creatininase was estimated to be 33 700D by SDS-PAGE. The creatininase was stable in the pH range between 6.0 - 9.0 and below 60 degrees C . Its Km value for creatinine was estimated to be 21.14 mmol/L. The enzyme was markedly inactivated by incubation with 1 mmol/L of Hg2+, Ag2+, Li+, Cu2+ and 20 mmol/L of 1, 11-Phananthroline respectively. Activation was observed when the enzyme was incubated with 1 mmol/L of Co2+ and Mn2+.
Amidohydrolases ; isolation & purification ; metabolism ; Arthrobacter ; enzymology ; Bacterial Proteins ; isolation & purification ; metabolism ; Chromatography, DEAE-Cellulose ; methods