Abstract:

In order to obtain the gene encoding single-chain variable fragment (scFv) antibody against atrazine, the amino
acid sequence of scFv was deduced by DNAStar software and its physical and chemical properties, and secondary and
tertiary structures of its encoding protein were analyzed according to bioinformatics online websites. The results showed that
the full-length scFv gene had 744 bp and encoded 248 amino acids. The relative molecular weight of scFv was 26 061.9, and
the antibody had isoelectric point (pI) of 7.81 and belonged to alkaline and stable protein. The predicted secondary structure
comprised 17 α-helices, 85 extended strands, 19 β-turns and 127 random coils. The mimic tertiary structure model of scFv
indicted that all six complementarity-determining regions (CDRs) of light chain variable (VL) and heavy chain variable (VH)
region contributed to the antigen-binding sites. This research can lay the foundation for further studies on the expression,
purification and bioactivity of genetically engineered antibodies.

Key words: atrazine, single-chain variable fragment (scFv), structure prediction