The invention provides an N-terminal brain natriuretic peptide variant protein and preparation and application thereof. The N-terminal brain natriuretic peptide variant protein includes two antigenicepitope peptide fragments of a flexible chain peptide segment connected in series with a wild-type N-terminal brain natriuretic peptide molecule; the flexible chain peptide segment is a short peptidesequence composed of n flexible amino acids, and n is a positive integer of not less than 11. According to the invention, the recombinant plasmid containing the variant protein gene is constructed byusing the genetic engineering technology, and after the recombinant plasmid is transformed into Escherichia coli BL21DE3, a large amount of expression of the variant protein is induced under the condition of a low temperature. The N-terminal brain natriuretic peptide variant protein molecule has higher expression level, immunogenicity and stability compared with wild-type N-terminal brain natriuretic peptide molecules, and can be widely applied to the preparation of calibrators and quality control products of N-terminal brain natriuretic peptide detection kits when matched with commercial paired antibodies.
N-terminal brain natriuretic peptide variant protein and preparation method and application thereof