7 results about "Mammalian expression" patented technology

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.

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.

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 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.