Abstract: The study cloned, expressed, purified and performed preliminary functional analysis of Malectin (ApMLEC) from Antheraea pernyi. Based on the known cDNA database of Antheraea pernyi, the ApMLEC gene was cloned by PCR and the sequence information was analyzed by bioinformatics. The gene was ligated to the pET-28a prokaryotic expression vector, and the recombinant protein was purified by Escherichia coli BL21 (DE3) expression system and affinity chromatography. The ability of the protein to bind polysaccharides, agglutinate bacteria and inhibit bacterial growth was investigated. The antiviral activity of the protein was explored by ligating it to the transfer vector pApBacDual-egfp. The results showed that the gene consisted of 798 bases encoding 266 amino acids and the purified recombinant protein had a molecular weight of about 33 ku with the His-tag. The ApMLEC could bind to maltose, lipopolysaccharide and peptidoglycan. It could agglutinate bacteria and inhibit the growth of Escherichia coli and Staphylococcus aereus with a minimum inhibitory mass concentration of 250 μg/mL for both. It also inhibited the replication of Antheraea pernyi nuclear polyhedron viruses. The preliminary functional analysis of ApMLEC suggested that it might play an important role in the natural immunity of Antheraea pernyi, and laid the foundation for future research on the immune system of this species.

Key words: Antheraea pernyi, ApMLEC, antiviral, antibacterial, agglutinating bacteria