Chemically modified basic group-containing single-stranded DNA aptamer capable of specifically recognizing anthrax protective antigen PA83 and application thereof

Abstract

The invention discloses a chemically modified base-containing single-stranded DNA aptamer capable of specifically recognizing anthrax protective antigen PA83 and application thereof. According to thechemically modified base-containing single-stranded DNA aptamer, the anthrax protective antigen (PA83) is taken as a target, a nucleic acid library containing chemically modified nucleotides is utilized, a high-affinity aptamer AP5 is screened out by a paramagnetic particle method SELEX, and the aptamer can specifically recognize PA83 protein in the environment of various interference proteins; the aptamer can be applied to an aptamer biosensor based on a surface plasmon resonance technology and a fluorescence polarization technology and used for detecting PA83 protein so as to detect bacillusanthracis, and the aptamer has the potential of being applied to construction of a novel bacillus anthracis protective antigen detection technology.

Description

technical field [0001] The invention belongs to the field of biotechnology, and in particular relates to a chemically modified base-containing single-stranded DNA aptamer specifically recognizing anthrax protective antigen PA83 and its application. Background technique [0002] The infection form of Bacillus anthracis is spores, which can enter the body through skin wounds, digestive tract or lungs, among which aerosol transmission is the main transmission route of bioterrorism attacks. The protective antigen PA is an important part of the anthrax toxin complex. The anthrax protective antigens commonly referred to are PA83 and PA63. Studies by the U.S. Army Institute of Infectious Diseases and the U.S. Centers for Disease Control and Prevention have shown that a large amount of PA83 exists in the culture supernatant of anthrax spore germination and in the body fluids of patients before infection. Therefore, the development of recognition elements that recognize PA83 protein...

AI Technical Summary

Problems solved by technology

However, at present, the initial library based on the natural base system only has four variables of ACT(U)G, which is not as good as the combination of more than 20 amino acids of the antibody, and in order to ensure the specificity of the aptamer, the random base sequence should not be too long. The length is generally 25-42 bases, which further limits the amount of initial library information

[0004] Many studies at home and abroad have shown that the application of chemically modified nucleotides to library construction can greatly increase the amount of library information, thereby screening aptamers with better performance, but different modification methods have a significant impact on the function of aptamers

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