Nano antibody of clostridium difficile glutamate dehydrogenase, and encoding sequence, screening method and application thereof

Abstract

The invention provides a nano antibody of clostridium difficile glutamate dehydrogenase, and an encoding sequence, a screening method and the application thereof and belongs to the technical field ofimmunology. The invention provides an amino sequence of the nano antibody of clostridium difficile glutamate dehydrogenase. By using a phage display technology, a sequence with a constant region specific gene is inserted into a vector of a phage encoding coat protein, after recombination expression, an exogenous gene expression product is fused with the phage encoding coat protein and demonstratedon the surface of phage to form a phage demonstration library, phage monocloning of the nano antibody is expressed through screening, and the nano antibody is prepared through sequencing. Phage-ELLSAidentification shows that the phage that the nano antibody is expressed on the surface can be specifically combined with clostridium difficile glutamate dehydrogenase antigen and has a good developing property, the result shows that the nano antibody has a good combination property with glutamate dehydrogenase, therefore, the nano antibody can be adopted to replace a common antibody applied to aclostridium difficile immunodetection kit.

Description

technical field

[0001] The invention belongs to the technical field of immunology, and in particular relates to a nanobody of Clostridium difficile glutamic acid dehydrogenase, its coding sequence, its screening method and application. Background technique

[0002] A heavy-chain antibody naturally deficient in light chains is present in the peripheral blood of camels, which contains only a heavy-chain variable domain and two conventional CH2 and CH3 domains. The single-domain antibody obtained by cloning the variable region of the heavy chain by PCR technology is called VHH antibody (variable domain of heavy-chain antibody, VHH). nm, 4nm long, so it is also called nanobody (nanobody, Nb). Nanobody is the smallest antibody with complete antigen-binding activity known so far. Due to its small size, it has strong antigen-antibody binding ability and can be highly expressed in prokaryotic and eukaryotic cells. In addition, it also has a stable structure and high hydrophilicity...

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