Method for preparing ELISA (enzyme-linked immuno sorbent assay) enzyme-labelled antigen through utilizing avidin binding peptide and avidin combining principle

Abstract

The invention discloses a method for preparing an ELISA enzyme-labelled antigen through utilizing an avidin binding peptide and avidin combining principle. The enzyme-labelled antigen is formed by recombining, antigenically fusing and mixing an enzyme-labelled streptavidin (one type of avidins) with a streptavidin binding peptide (SBP). The method comprises steps of: utilizing the principle that the enzyme-labelled streptavidin and biotin can be specifically bound with each other, and adopting a genetic engineering method to structure the streptavidin binding peptide (SBP) with a simulated biotin structure with antigenic protein molecules so as to form a fusing protein; and binding the SBP in the fusing protein with the enzyme-labelled streptavidin through affinity, and thus forming a novel enzyme-labelled antigen with antigenic activity and enzymatic activity. The method does not need special chemical groups as a coupling target position and has wide applicability; and moreover, the antigenic molecules are not directly labeled, the influence on an antigenic structure is reduced, and the steric hindrance of a labeled object to antigen-antibody reaction is decreased, so that the detection sensitivity is improved.

Description

technical field [0001] The invention belongs to the field of immunology and biotechnology, and specifically relates to a method for constructing and preparing an ELISA enzyme-labeled antigen using the principle of combining an avidin-binding peptide with avidin. The enzyme-labeled antigen prepared by this method can be used for detection Antibody enzyme-linked immunosorbent assay method was established. Background technique [0002] Enzyme-labeled antigens are used in the detection of antibodies in enzyme-linked immunosorbent assay (Enzyme Linked Immunosorbent Assay, ELISA). The traditional enzyme-labeled antigen preparation method is based on the chemical coupling method, that is, the chemical reaction between the antigen molecule and the cross-linking agent forms a covalent bond and connects. Different cross-linking agents react to different chemical groups (mainly primary amines, thiols, carboxyls, etc.) on the antigen molecule. Therefore, the labeling efficiency and th...

AI Technical Summary

Problems solved by technology

If the number of chemical groups available for labeling in the antigen molecule is small or if they are in the internal structure of the molecule, labeling will be inefficient; if these groups are on or near the epitope, the labeling may change The spatial structure of the epitope and the steric hindrance will affect the binding to the antibody and affect the detection effect

The structures of various antigens are diverse, and many of their main functional regions are still uncertain, so it is not sure whether the labeling process will affect their structure and function, thereby reducing or even losing their ability to bind to antibodies

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