Construction of human Fab library and screening of a single-domain antibody of amyloid-beta 42 oligomers

摘要

Research Highlights (1) We constructed a na?ve human Fab library and obtained a human Fab antibody and a single-domain antibody that specifically recognized amyloid-beta (Aβ)42 oligomers. (2) The Fab library was constructed using a parallel insertion strategy, which increased library capacity, variety and screening rate of positive clones. (3) We screened beta-amyloid oligomer single-domain antibodies using a protein-on-membrane technique, which removed interference due to binding of amyloid-beta single-domain antibodies, and increased the possibility of obtaining anti-beta-amyloid oligomer conformation-dependent antibodies. Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oligomers and constructed a na?ve human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that specifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked immunosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study successfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.