Animals ; Codon, Nonsense ; Disease ; genetics ; Drosophila ; genetics ; metabolism ; Drosophila Proteins ; genetics ; Humans ; Pseudogenes ; Receptors, Odorant ; genetics

According to the amino acid sequence of des-pGlu1-Brazzein, 4 pairs of oligonucleotide with cosmic site were synthesized by using yeasty biased codons. After linkage and PCR, the 179 bp code area of des-pGlu1-Brazzein was obtained and inserted into pPIC9K, which resulted in the recombinant expression vector pPIC9K-Bra. By digestion with Sal I, the lined pPIC9K-Bra was transformed into Pichia pastoris GS115 by electric shock. The results of expression indicted that the secreted target protein accounted for 51.6% of total protein in the supernatant and showed biological activity after purification.
Codon ; Pichia ; genetics ; metabolism ; Plant Proteins ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Sweetening Agents

OBJECTIVETo enhance the expression level of human papillomavirus (HPV) 16 L2E7 in Escherichia coli (E. coli), in aim of providing high-level expression of HPV16 L2E7 strain for pre-clinical high-throughout production.

METHODSThe whole L2E7 gene was optimized by software of Synthetic Gene Designer, reflecting E. coli codon usage. Two parts of codon-optimized gene were cloned into pET9a vector step by step. The positive clone, which was sequenced to be corrected, was transfected to BL21 (DE3+) via isopropyl-beta-D-thiogalactoside (IPTG) induction. They produced the HPV16 L2E7 fusion protein, which was further detected by SDS-PAGE and Western blot. The induction temperature, induction time, and IPTG concentration were also optimized by a series of experiments. Further purification modes of this protein were also explored.

RESULTSCodon-optimized HPV16 L2E7 was highly expressed in E. coli. The target protein accounted for nearly 60% of the total cell extract.

CONCLUSIONHigh-level expression of HPV16 L2E7 was successfully constructed.

Codon ; Escherichia coli ; genetics ; metabolism ; Human papillomavirus 16 ; metabolism ; Papillomavirus E7 Proteins ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics

There are many E. coli rare codons in the gene of porcine interferon alpha-1. In order to obtain high expression of poIFN-alpha1 in E. coli, the cDNA encoded poIFN-alpha1 mature protein was synthesized using biased codons of E. coli without changing the original amino acid sequence and the terminator was changed as TAA. At the same time, Adenine and Thymine were used to the largest extent near the 5' terminus of poIFN-alpha1 mature protein gene. The synthesized gene was inserted into the Eco RI and Sal I site of the expression vector pRLC resulting pRLC-poIFN-alpha1. The poIFN-alpha1 is highly expressed in E. coli DH5alpha when the induction was carried out at 42 degrees C . The expressed poIFN-alpha1 account for 24.5% of the total cellular proteins and existed as inclusion body. The poIFN-alpha1 inclusion body was dissolved in 6mol/L guanidine chloride contained DTT and subsequently the denatured poIFN-alpha1 was re-natured by dilution in refolding buffer containing GSH and GSSH. In the present study it was found that the denatured poIFN-alpha1 was most efficiently re-natured in refolding buffer containing 1 mol/L guanidine chloride. In order to obtain pure protein, the concentrated re-natured poIFN-alpha1 was purified by Sephacryl S-200 chromatography. As a result, the purified poIFN-alpha1 is verified to be of high cytokine activity by inhibiting the cytopathic effect of vesicular stomatitis virus in MDBK cells, which is about 6.4 x 10(6) u/mg. This study paved the way for large-scale production of recombinant poIFN-alpha1 and its usage in virus disease control of pigs.
Animals ; Codon ; genetics ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Interferon-alpha ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; Transduction, Genetic

Codon ; Herpes Simplex ; virology ; Herpesvirus 1, Human ; genetics ; metabolism ; Humans ; Protein Binding ; Protein Biosynthesis ; Viral Proteins ; genetics ; metabolism

Protozoan ciliates are a group of unicellular eukaryotes. The special characteristics of stop codons usage in termination of protein biosynthesis in ciliates cells makes them an ideal model to study the mechanism of stop codon recognition of polypeptides release factors. To localize the functional positions of biomolecules in ciliates cell, we constructed a macronuclear artificial chromosome containing a gene encoding red fluorescence protein (EoMAC_R) based on the structural characteristics of ciliates chromosome. Three factors, L11, eRF1a, and eRF3 that are involved in termination process of protein synthesis were colocalized in Euplotes octocarinatus cells by using novel EoMAC_R and the previously constructed EoMAC_G. The results indicated that protein synthesis mainly occurred inside the "C" shape macronucleus, suggesting that EoMAC could be a useful tool for localizing biomolecules in ciliates cell.
Chromosomes, Artificial ; Codon, Terminator ; metabolism ; Euplotes ; chemistry ; Peptide Termination Factors ; analysis ; genetics ; metabolism ; Peptides ; metabolism ; Protein Biosynthesis ; genetics ; Protozoan Proteins ; analysis ; genetics ; Ribosomal Proteins ; analysis ; genetics

Codon bias is an important factor which influences heterologous gene expression. Optimizing codon sequence could improve expression level of heterologous gene. In order to improve the expression level of BmK AngM1 gene encoding the analgesic peptide from Buthus martensii Karsch in Pichia pastoris, the codon-optimized BmK AngM1 gene according to its cDNA sequence and the preference codon usage of P. pastoris were cloned into expression vector pPIC9K and then transformed into P. pastoris. The expersion of recombinant BmK AngM1 (rBmK AngM1) was inducced by methanol in the medium, and the expression level of the optimized BmK AngM1 gene was 3.7 times of the native one. These results suggested that the expression of BmK AngM1 in P. pastoris could be successfully improved by codon optimization.
Amino Acid Sequence ; Animals ; Codon ; genetics ; Gene Expression ; Pichia ; genetics ; metabolism ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Scorpion Venoms ; genetics ; isolation & purification ; metabolism ; Scorpions ; chemistry ; Transformation, Genetic

The heterologously expressed L1 protein of human papilomavirus 16 can assembly into virus-like particles (VLPs), which has been used as prophylactic vaccine for cervical carcinoma. To express L1 protein in Hansenula polymorpha, we analyzed the codon usage of the native gene of L1 protein and redesigned the encoding sequence according to the codon bias of H. polymorpha. We used assembly PCR to synthesize the native gene HPV16L1-N and the codon optimized gene HPV16L1. The synthesized genes were cloned into pMOXZa-A vector to generate plasmids pMOXZ-HPV16N and pMOXZ-HPV16. The expression cassettes MOXp-HPV16L1(N)-AOXTT were cloned into YEp352 vector and transferred into H. polymorpha. After methanol inducement, the expression of L1 protein in H. polymorpha was detected from the codon optimized gene HPV16L1 rather than the native gene HPVI6L1-N. The parameters for induced cultivation for strain HP-U-16L with HPV16L1 were investigated in shaking flask cultures. After induced cultivation in YPM (pH 7.0) medium supplemented with methanol to a final concentration of 1.0% every 12 h at 37 degrees C for 72 h, the recombinant produced 78.6 mg/L of L1 protein. This work offers the possibility for the production of prophylactic vaccine for cervical carcinoma by H. polymorpha.
Capsid Proteins ; biosynthesis ; genetics ; Cloning, Molecular ; Codon ; genetics ; Genetic Vectors ; genetics ; Human papillomavirus 16 ; genetics ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

The present study was designed to investigate the effects of start codon of nosM on the biosynthesis of nosiheptide. Target genes were amplified by overlap PCR. After homologous recombination to construct engineered strains, nosiheptide production was analyzed by HPLC. Three mutants with different start codon of nosM were constructed, and nosiheptide production of each mutant was analyzed and compared. Replacement of the start codon of nosM significantly decreased the production of nosiheptide. In conclusion, start codon usage could greatly affect the biosynthetic efficiency in the biosynthetic gene cluster of nosiheptide.
Anti-Bacterial Agents ; biosynthesis ; Chromatography, High Pressure Liquid ; Codon, Initiator ; Escherichia coli ; Genes, Bacterial ; Mutation ; Streptomyces ; genetics ; metabolism ; Thiazoles ; metabolism

To construct a safer and more efficient gene engineering Lactococcus Lactis for expressing phenylalaine ammonia lyase (PAL) which will be benefit for PKU therapy, pal cDNA of Parsly and synthesized sequence based on Lactococcus Lactis bias codons were recombined into two Lactococcus Lactis NICE systems. The activities of the expressed PAL were detected, and the effect of Lactococcus Lactis bias codons on the expression of exterior protein was analyzed. The results showed that the expression level of PAL was increased by using Lactococcus Lactis bias codons in both Lactococcus Lactis NICE systems. Through which several safer andmore efficient strains of the gene engineering Lactococcus Lactis were obtained.
Cloning, Molecular ; Codon ; genetics ; Genetic Vectors ; genetics ; Lactococcus lactis ; genetics ; metabolism ; Phenylalanine Ammonia-Lyase ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; metabolism ; Transformation, Bacterial