2241 results about "Prokaryotic expression" patented technology

The present invention provides methods and compositions for improved expression and production of recombinant antibodies in prokaryotic expression systems. Particularly contemplated are prokaryotic expression and production of full length aglycosylated antibodies. The antibody products of the invention can be used in various aspects of biological research, diagnosis and medical treatment.

The invention provides a method for knocking out a drug resistance gene mcr-1 through CRISPR-Cas9 in vitro and specialized cell penetrating peptide thereof. The method comprises the steps that a CRISPR-Cas9 system is constructed according to a target point sequence of an mcr-1 drug resistance gene sgRNA identification zone, a base sequence of the target point sequence is shown as SEQ NO.1, in the constructed CRISPR-Cas9 system, a T7 promoter is inserted into the portion in front of a start point of sgRNA transcription, a prokaryotic expression vector of Cas9 protein is constructed, regulation is conducted through the T7 promoter, the specialized cell penetrating peptide CPP2a is utilized for knocking out the mcr-1 drug resistance gene, a carrier pCas9-mcr is brought into a microbial cell, the microbial species can be gram negative bacteria, and the phenomenon that microbial mcr-a drug resistance gene is knocked out in vitro is achieved.

The invention relates to a method for recombinating and expressing human fibroblast growth factors, which comprises following steps: fusing an FGF-21 gene and a molecular chaperone Sumo sequence, building a new prokaryotic expression vector, transforming escherichia coli, thereby building engineering bacteria, and obtaining the FGF-21 through culturing the engineering bacteria and inducing expression. The method of the invention can promote soluble expression of protein, which is beneficial for folding recombined protein correctly and is convenient for separating and purifying the protein. Activity detection proves that the recombined protein which is obtained has comparatively high biological activity and the bioactivity is equivalent to the bioactivity of FGF21standard products.

The invention relates to an amino acid sequence of a recombinant human papillomavirus L1 capsid protein, a nucleotide sequence which encodes the amino acid sequence and a recombinant vector and an expression host which contain the nucleotide sequence. The invention further relates to an application of a HPV L1 protein which is composed of the amino acid sequence in the preparation of vaccines, drug combination and diagnostic antigens or antibodies. The invention allows the recombinant HPV L1 capsid protein which is expressed in a prokaryotic system to be dissolvable in water by the modification of the HPV L1 wild-type sequence, and an L1 pentamer which has the same immunogenicity and antigenicity with the VLP of HPV L1 is obtained by expression. The invention allows the industrial production of the HPV L1 capsid protein by utilizing the prokaryotic expression system to become a reality, compared with the currently used eukaryotic expression system, the invention has the advantages of more stable quality of the products, higher yield, low cost and convenient quality control, which has great economic benefits and social effects.

The invention relates to the clone and the expression of alpha-cyclodextrin glycosyltransferase (alpha-CGTase), which belong to the field of enzyme gene engineering and enzyme engineering. The cgt gene expression method comprises the following steps: obtaining cgt gene SEQ ID NO:1 from total DNA of Peanibacillus macerans JFB05-01; selecting plasmid pET20b(+) as the expression vector of cgt gene; and selecting E.coli BL21(DE3) as the expression host to achieve high-efficiency extracellular expression of the cgt gene, wherein the cgt gene has 2,061 nucleotides and 687 coded amino acids; prokaryotic expression plasmid is constructed; and alpha-CGTase is expressed by transformed E.coli. Recombinase has cyclization activity and can transform starch and relevant matrix into cyclodextrin. The recombined alpha-CGTase has an optimal temperature of 40 to 45 DEG C and an optimal pH value of 5.5, and has higher thermal stability below 40 DEG C and poor thermal stability above 50 DEG C. The alpha-CGTase meets the requirement for industrial application such as food and medicines, and can be used for industrial production of alpha-cyclodextrin and beta-cyclodextrin.

The invention discloses a method to increase human papilloma virus L1 protein pronucleus expression productivity and also discloses a encode HPV L1 protein codon majorizing nucleic acid sequence from this method, which is characterized by the following: supplying expression carrier and host cell and HPVL1 protein poly body of nucleic acid sequence; disclosing appliance in preparing vaccine, drug compound and immunodiagnosis or antibody. The nucleic acid sequence expressing quantity possesses distinctive improvement, which decreases the preparing cost effectively.

The invention provides methods and compositions for improved expression and production of recombinant antibodies in host cell expression systems. In particular, prokaryotic expression and production of antibodies with modified hinge cysteine residues are provided. The invention further provides compositions, kits and articles of manufacture for practicing methods of the present invention.

The invention relates to a competitive ELISA method based on a foot-and-mouth disease A type VP1 protein and its monoclonal antibody, also relates to a preparation method of the foot-and-mouth disease A type VP1 protein, and a preparation method of the monoclonal antibody of the foot-and-mouth disease A type VP1 protein, and belongs to the technical field of animal immunological detection. In the invention, a primer pair C1 and C2 and a primer pair E1 and E2 are amplified to obtain a gene sequence of the foot-and-mouth disease A type VP1 protein, the foot-and-mouth disease A type VP1 protein is obtained by constructing an expression plasmid, introducing the expression plasmid into a prokaryotic expression host and carrying out inducible purification, the foot-and-mouth disease A type VP1 protein monoclonal antibody is obtained by treating the foot-and-mouth disease A type VP1 protein as an antigen through a hybridomas technology, and the competitive ELISA method used for detecting a foot-and-mouth disease A type antibody is established based on the foot-and-mouth disease A type VP1 protein and its monoclonal antibody. The detection method has a strong specificity and a good stability, and can be used for detecting a foot-and-mouth disease A type serum antibody. By comparing a result obtained through the detection method with a liquid phase blocking ELISA kit, the coincidence rate is 95.8%.

The invention discloses a large yellow croaker hepcidin antibacterial peptide and a preparation method thereof, relating to fish gene engineering in the biotechnology field, and providing a large yellow croaker hepcidin antibacterial peptide and a preparation method thereof. The preparation method of the large yellow croaker hepcidin antibacterial peptide comprises the following steps: cloning a large yellow croaker hepcidin antibacterial peptide gene; constructing a recombinant vector; converting a host cell; selecting positive clone for prokaryotic expression; separating and purifying an expression product; and obtaining the large yellow croaker hepcidin antibacterial peptide. During separation and purification, the yield of protein is improved, thus solving the problem of protein precipitation when the hepcidin antibacterial peptide expresses renaturation. The solution has simple preparation and low cost. The prepared large yellow croaker hepcidin antibacterial peptide has high broad-spectrum antimicrobial activity, can be used for scientific researches, can serve as feed additive for preventing and curing diseases of sea farming fishes and has wide application prospect.

The invention discloses a bacterial strain for producing lycopene and an application of the bacterial strain, and belongs to the field of synthetic biology. The bacterial strain for producing lycopene contains a mevalonate pathway and a related gene which is synthetized by the lycopene optimized by a codon; and the synthetic gene sequence of the lycopene optimized by the codon is shown in SEQ ID NO.1-3. The bacterial strain can be used for producing the lycopene; and a seed solution of the bacterial strain is inoculated into a culture medium containing a carbon source to carry out prokaryotic expression, so as to obtain the lycopene. The gene synthetized by the lycopene is optimized by the codon or each protein of the mevalonate pathway is closer to A to B:ERG13:tHMG1:ERG12:ERG8:MVD1:Idi=1:10:2:5:5:2:5; and production of the lycopene can be further promoted. By adopting the bacterial strain, the yield of the lycopene can be greatly improved to over 1g / L; and the fermentation cycle is shortened by over 50%.

The invention provides methods and compositions for improved expression and production of recombinant antibodies in host cell expression systems. In particular, prokaryotic expression and production of antibodies with modified hinge cysteine residues are provided. The invention further provides compositions, kits and articles of manufacture for practicing methods of the present invention.

Provided are methods of generating a functional mammalian single chain MHC class I complex in prokaryotic expression systems and a host cell transformed with expression construct(s) capable of expressing a functional human single chain MHC class I complex capable of presenting specific antigenic peptides restricted to specific CTL clones.