13 results about "Mammalian expression" patented technology

The invention discloses a recombinant I-type collagen, a preparation method and application, and belongs to the technical field of binding tissue peptides, the recombinant I-type collagen is formed by sequentially connecting the following modules in series from the N terminal to the C terminal: a signal peptide, a truncated I-type collagen and a His tag; the nucleotide sequence of the truncated I type collagen is as shown in any one of SEQ ID NO.3, SEQ ID NO.4, SEQ ID NO.5 and SEQ ID NO.6; the nucleotide sequence of the truncated I type collagen is as shown in any one of SEQ ID NO.3, SEQ ID NO.4, SEQ ID NO.5 and SEQ ID NO.6; according to the invention, a mammalian expression system and a 293T cell line are used for expressing recombinant I-type collagen, so that collagen with natural biological activity is obtained, and the proliferation efficiency and repair capacity of the collagen for promoting HSF cells can be improved.

A chimeric nucleotide sequence that corresponds to an encoded fusion protein comprising a polyepitope resulting from selecting and juxtaposing multiple epitopes from a coronavirus protein to induce an immune response in mammals. In one embodiment, said fusion protein comprises: a) a first peptide consisting of epitopes found in the amino acid sequence of replicase polyprotein 1ab (PR1ab); b) a first spacer; c) a modified form of herpes simplex virus type 1 (HSV-1) glycoprotein D (gD). In one embodiment, the replicase polyprotein is defined by SEQ ID NO: 96 flanked by a gD fragment comprising the amino acid sequence defined by SEQ ID NO: 98 in the N-terminal portion and another gD fragment comprising the amino acid sequence defined by SEQ ID NO: 100 in the C-terminal region. Use of the fusion protein has surprising results in inducing cellular and humoral immune responses against coronavirus, SARS-COV-2, and related viruses.

The invention relates to a novel human immunodeficiency virus envelope protein antigen expressed by mammals. Various embodiments of the invention relate to a polypeptide comprising 1-10 epitopes or more of the HIV envelope protein and a fusion protein, wherein the polypeptide lacks a transmembrane domain of the HIV gp41 protein. Such polypeptides can be expressed in mammalian cells, such as human cells, to produce polypeptides useful, for example, in the development of novel anti-HIV antibodies. The polypeptides described herein and the novel antibodies developed therefrom are generally useful in medical diagnostics, and they can also be used in the prophylactic and therapeutic treatment of HIV.

The application belongs to the technical field of biological medicine, and particularly relates to an anti-FOLR1 nanobody and a preparation method and application thereof. The anti-FOLR1 nanobody comprises a framework region and a complementarity determining region, and the complementarity determining region amino acid comprises CDR1, CDR2 and CDR3. The application adopts automatic panning and a mammalian expression system, significantly improves the screening efficiency and antibody expression quality, greatly shortens the development cycle, and provides an efficient tool for FOLR1 targeted diagnosis and treatment. The obtained anti-FOLR1 nanobody exhibits excellent specific recognition and binding capacity.

The invention discloses a novel Fc effect eliminated framework flow antibody, and belongs to the technical field of biological medicine. The antibody comprises a mutation combination of L234A, L235A, P238S and D265A in a heavy chain CH2 region, and can further comprise S267E and L328F mutations, so that the Fc receptor binding capacity is effectively reduced. The type of the antibody can be selected from multiple forms of scFv-Fc, (scFv) 2-Fc, scFv / scFv-Fc, Fab / scFv-Fc and the like. The invention also provides a nucleic acid sequence for coding the antibody and a preparation method of the antibody. The preparation method comprises the following steps: introducing specific mutation into a CH2 region of recombinant rabbit IgG, and expressing and purifying in a mammal expression system to obtain the antibody. When the antibody is applied to a flow cytometry detection reagent, a non-specific background signal caused by Fc receptor combination can be effectively eliminated, and the detection specificity and accuracy are improved.

The present invention relates to the use of an oligosaccharyl transferase (OST) enzyme obtained from Trypanosoma brucei to improve the expression of a functional and stable recombinant protein in a mammalian expression system. In particular, the present invention provides a mammalian cell comprising at least one nucleic acid sequence encoding at least one OST protein or a functional fragment thereof wherein at least one OST protein is a trypanosomes OST protein, preferably wherein at least one OST protein is a trypanosomes buchneri OST protein.

To provide a mammalian expression system for producing recombinant porcine circovirus type 2 (PCV2) virus-like particles (VLPs).SOLUTION: A mammalian expression system includes a mammalian cell and a plasmid that comprises a PCV2 gene encoding a capsid protein. The PCV2 gene is codon optimized, and the mammalian cell is transfected with the plasmid. The expression system produces recombinant PCV2 VLPs, such as PCV2d VLPs. Also, provided herein are a method for producing porcine circovirus type 2 (PCV2) virus-like particles (VLPs), as well as a PCV2 VLP generated by the method.SELECTED DRAWING: Figure 1A

The present invention provides a novel method for determining a long-chain non-coding ribonucleic acid interaction protein. The present invention provides a fusion protein formed by BASU and dCasRx, a mammalian expression vector for expressing said fusion protein. The method for determining the lncRNA interaction protein according to the present invention comprises: co-transfecting a mammalian expression vector that expresses the fusion protein and a gRNA that specifically targets the target lncRNA into target cells, thereby BASU specifically biotin-labeling effector proteins nearby; isolating the biotinylated proteins by using a streptavidin affinity coupled magnetic bead and then eluting, and digesting by trypsin and quantitatively analyzing by a label-free mass spectrometry. The present invention can highly credibly determine the proteins that interact with lncRNA.

Provided are a flavivirus mini-replicon, a flavivirus single-round infectious particle, a preparation method therefor, and a pharmaceutical composition thereof. The flavivirus mini-replicon comprises a promoter, a 5' untranslated region, a first nucleic acid fragment, an exogenous gene, a second nucleic acid fragment and a 3' untranslated region. The flavivirus single-round infectious particle carries the flavivirus mini-replicon. The pharmaceutical composition contains the flavivirus single-round infectious particle and a pharmaceutically acceptable carrier. The flavivirus mini-replicon can effectively express the exogenous gene and thus can serve as an expression vector for expressing an exogenous gene in mammals and for use in gene therapy.

The invention relates to the technical field of bioengineering, and particularly discloses a screening method of a specific signal peptide for expressing human serum albumin and a method for establishing a mammal expression system.The screening method comprises the steps that a human-derived signal peptide sequence and a mouse-derived signal peptide sequence are collected, and a human-derived signal peptide library and a mouse-derived signal peptide library are constructed; writing an MATLAB script to generate an HSA SPC region mutant library; signal peptides in a mouse signal peptide library, a human signal peptide library and an HSA SPC region mutant library are predicted by using SignalP 6.0 to obtain an SP score and a CS score of each signal peptide, and high-throughput screening is performed to obtain the specific signal peptide capable of expressing human serum albumin. The method breaks through an intelligent screening platform supporting 106-order sequence parallel analysis, the adaptive SP of the target protein can be rapidly screened out, the recombinant drug protein expression quantity is improved, and the development cycle of a mammal expression system is greatly shortened.

The application discloses a novel Fc effector-eliminated scaffold flow antibody, and belongs to the technical field of biological medicine. The antibody comprises a L234A, L235A, P238S and D265A mutation combination in a heavy chain CH2 region, and can further comprise S267E and L328F mutations, so that the Fc receptor binding capacity is effectively reduced. The antibody type can be selected from a scFv-Fc, (scFv)2-Fc, scFv / scFv-Fc and Fab / scFv-Fc and the like. The application further provides a nucleic acid sequence for coding the antibody and a preparation method, which comprises introducing specific mutations in a CH2 region of recombinant rabbit IgG, expressing in a mammalian expression system and purifying to obtain the antibody. When the antibody is applied to a flow cytometry detection reagent, the non-specific background signal caused by Fc receptor binding can be effectively eliminated, and the specificity and accuracy of detection are improved.

The present invention discloses a recombinant type I collagen, a preparation method and an application thereof, belonging to the technical field of tissue-binding peptides. The recombinant type I collagen comprises the following modules connected in series from the N-terminus to the C-terminus: a signal peptide, a truncated type I collagen, and a His tag; the nucleotide sequence of the truncated type I collagen is shown in any one of SEQ ID NO.3, SEQ ID NO.4, SEQ ID NO.5 and SEQ ID NO.6; the present invention utilizes a mammalian expression system and a 293T cell line to express the recombinant type I collagen, thereby obtaining collagen with natural biological activity and improving the proliferation efficiency and repair ability of HSF cells promoted by the collagen.

The present invention involves improving the expression of functional and stable recombinant proteins in mammalian expression systems using an oligosaccharide transferase (OST) enzyme obtained from Trypanosoma brucei. In particular, the present invention provides mammalian cells comprising at least one OST protein or at least one nucleic acid sequence encoding a functional fragment thereof, wherein the at least one OST protein is a Trypanosoma spp. OST protein, and preferably, the at least one OST protein is a Trypanosoma brucei OST protein.