Translocation ribonucleic acid (tRNA) is one of the important components in protein synthesis. In order to explore the effect of the changes of tRNAs corresponding to rare codons (rarity tRNAs) on the expression of exogenous genes, the co-expression system of rare tRNA gene and exogenous gene in Pichia pastoris was constructed. The expression of GFP in P. pastoris can be greatly reduced when a repressor region composed of four continuous proline rare codon CCG was added into the GFP gene. The expression amount of the repressed GFP could be increased about 4.9% when tRNAProCCG gene was cointegrated to the 3' of the repressed GFP gene through pPIC9K to the genome of P. pastoris GS115. Meanwhile, the expression amount of the repressed GFP increased about 12.5% by integrating the repressed GFP gene and tRNAProCCG gene to the genome of P. pastoris GS115 through pPIC9K and pFLDα, respectively. Using the same method, NFATc3T-GFP fusion gene and tRNAProCCG gene were co-expressed in P. pastoris GS115 resulting in 21.3% increased of the expression amount of NFATc3T-GFP fusion protein. In conclusion, tRNAProCCG gene has been confirmed to be a kind of rare tRNAs in P. pastoris GS115. Through co-expression of tRNAProCCG gene and heterologous genes which containing the continuous rare codon CCG, the expression of the repressed heterologous genes could be increased significantly. Furthermore, this co-expression system would contribute to screening and determining the other rare tRNAs.
Codon ; Pichia ; Recombinant Proteins

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 clone the FimA gene of fimbriae from Porphyromonas gingivalis (P. gingivalis) and to construct prokaryotic expression vector which was induced in E.coli BL21(DE3)pLyS in the form of fusion protein expression and to identify, purify the product of its expression.

METHODSTo clone the FimA gene of fimbriae from P. gingivalis and to construct prokaryotic expression vector pET15b-FimA vector which was transformed into the competent cells of BL21(DE3)pLyS. The expression of fusion protein was induced by isopropyl beta-D-1-thiogalactopyranoside (IPTG). With anti-6xHis Tag monoclonal antibody as the first antibody, the expressed fusion protein was characterized by Western blot and purified by Co(2+)-NTA affinity chromatography.

RESULTSCloned FimA gene sequences and inserted into expression vector of the FimA sequences were related to the sequence in GenBank database showed 100% homology. IPTG induced and then identified by Western blot showed a fragment of 4.1 x 10(4) has been expressed. Co(2+)-NTA affinity chromatography column was used to obtain high concentrations of FimA purified protein.

CONCLUSIONThe recombinant prokaryotic expression vector of pET15b-FimA was constructed and was expressed and purified successfully in E. coli BL21 (DE3)pLyS. This study laid the experimental foundation to further prepare for monoclonal antibodies of fimbriae of P. gingivalis and to develop the subunit protein vaccine of prevention of periodontitis.

FVIII is synthesized as a single chain precursor of approximately 280 kD with the domain structure of A1-A2-B-A3-C1-C2 and it circulates as a series of metal ion-linked heterodimers that result from cleavages at B-A3 junction as well as additional cleavages within B domain. Factor VIII is converted to its active form, factor VIIIa, upon proteolytic cleavages by thrombin and is a heterotrimer composed of the A1, A2, and A3-C1-C2 subunits. A1 subunits of factor VIIIa terminates with 36 residue segment (Met337-Arg372) rich in acidic residues. This segment is removed after cleavages at Arg336 by activated protein C, which results in inactivation of the cofactor. In the present study, site-directed mutagenesis of FVIII at Arg336 to Gln336 was performed in order to produce an inactivation resistant mutant rFVIII (rFVIIIm) with an extended physiological stability. A recombinant mutant heavy chain of FVIII (rFVIII-Hm; Arg336 to Gln336) and wild-type light chain of FVIII (rFVIII-L) were expressed in Baculovirus-insect cell (Sf9) system, and a biologically active recombinant mutant FVIII (rFVIIIm) was reconstituted from rFVIII-Hm and rFVIII-L in the FVIII-depleted human plasma containing 40 mM CaCl2. The rFVIIIm exhibited cofactor activity of FVIIIa (2.85 x 10(-2) units/mg protein) that sustained the high level activity during in vitro incubation at 37 degrees C for 24 h, while the cofactor activity of normal plasma was declined steadily for the period. These results indicate that rFVIIIm (Arg336 to Gln336) expressed in Baculovirus-insect cell system is inactivation resistant in the plasma coagulation milieu and may be useful for the treatment of hemophilia A.
Animal ; Baculoviridae/genetics ; Blotting, Western ; Cell Line ; Factor VIII/metabolism* ; Factor VIII/genetics ; Factor VIII/chemistry ; Factor VIII/biosynthesis ; Genetic Vectors ; Human ; Mutagenesis, Site-Directed ; Recombinant Proteins/metabolism ; Recombinant Proteins/genetics ; Recombinant Proteins/chemistry ; Recombinant Proteins/biosynthesis ; Spodoptera

Plant expression systems have been developed to produce anti-cancer vaccines. Plants have several advantages as bioreactors for the production of subunit vaccines: they are considered safe, and may be used to produce recombinant proteins at low production cost. However, several technical issues hinder large-scale production of anti-cancer vaccines in plants. The present review covers design strategies to enhance the immunogenicity and therapeutic potency of anti-cancer vaccines, methods to increase vaccine-expressing plant biomass, and challenges facing the production of anti-cancer vaccines in plants. Specifically, the issues such as low expression levels and plant-specific glycosylation are described, along with their potential solutions.
Biomass ; Bioreactors ; Glycosylation ; Plants ; Recombinant Proteins ; Vaccines* ; Vaccines, Subunit

Plant expression systems have been developed to produce anti-cancer vaccines. Plants have several advantages as bioreactors for the production of subunit vaccines: they are considered safe, and may be used to produce recombinant proteins at low production cost. However, several technical issues hinder large-scale production of anti-cancer vaccines in plants. The present review covers design strategies to enhance the immunogenicity and therapeutic potency of anti-cancer vaccines, methods to increase vaccine-expressing plant biomass, and challenges facing the production of anti-cancer vaccines in plants. Specifically, the issues such as low expression levels and plant-specific glycosylation are described, along with their potential solutions.
Biomass ; Bioreactors ; Glycosylation ; Plants ; Recombinant Proteins ; Vaccines* ; Vaccines, Subunit

Recombinant protein SMB(PRG4) containing two Somatomedin B domains and a small amount of glycosylation of repetitive sequences of proteoglycan 4 was cloned according to PGR4 gene polymorphism. Mature purification process was established and recombinant protein SMB(PRG4), with high-level expression was purified. By using size-exclusion chromatogaraphy and dynamic light scattering, we found that the recombinant protein self-aggregate to dimeric form. Structure prediction and non-reducing electrophoresis revealed that SMB(PRG4), was a non-covalently bonded dimer.
Glycosylation ; Protein Multimerization ; Proteoglycans ; chemistry ; Recombinant Proteins ; chemistry ; Somatomedins ; chemistry

An important index determination for clinical diagnosis of renal function is to assay the creatinine concentration in serum. In the analytical process applied with coupled-enzyme, the quality control of sarcosine oxidase (SOX) as a key enzyme is the first problem to be solved. In order to establish an efficient and laboratory-scale production of SOX, the recombinant sarcosine oxidase (r-SOX) gene was a high-level expression in E. coli induced with lactose on a large-scale fermentation in 300 L fermenter. The results suggested that the biomass concentration reached OD600 of 22 and the expression of recombinant sarcosine oxidase in E. coli accounted for about 25% of total soluble protein in culture after fermentation. The cell-free extract obtained from high pressure homogenizer was processed by selective thermal denaturation and then purified with Ni-Sepharose FF chromatography. The sarcosine oxidase with 97% purity, 25 U/mg specific activity and 92.4% activity recovery was obtained. The molecular weight with single peptide chain of 53 kD and 55 kD of recombinant sarcosine oxidase was assessed by SDS-PAGE in presence or absence of 2-mercaptoehanol and Sephacryl S-200 chromatography. This sarcosine oxidase was found to be a conjugated protein, yellow enzyme, which combined with FAD as prosthetic group by covalent linkage. The contaminant of catalase was not detected in the sample pool of this enzyme. In addition, a further test to the thermal stability of sarcosine oxidase was done. According to the above results, the development and utilization of this enzyme has been set up on a reliable foundation.
Escherichia coli ; Fermentation ; Recombinant Proteins ; biosynthesis ; Sarcosine Oxidase ; biosynthesis

Little is known about the prophylactic use of recombinant factor VIIa (rFVIIa) in patients undergoing surgery for a bleeding aorta employing cardiopulmonary bypass. We report the successful use of rFVIIa in a patient undergoing hypothermic circulatory arrest and prolonged cardiopulmonary bypass for repair of a DeBakey type III aortic dissection.
Aorta ; Cardiopulmonary Bypass ; Factor VIIa ; Hemorrhage ; Humans ; Recombinant Proteins

No Abstract Available.
Brucella abortus* ; Brucella* ; Immunity, Humoral* ; Jeju-do* ; Recombinant Proteins*