Abstract: Objective To isolate and purify antimicrobial polypeptides HMGN2 from human monocyte THP-1 and detect its antimicrobial activity of HMGN2 by agar diffusion test. Methods: HMGN2 antimicrobial polypeptide were purified by the Reverse Phase HPLC and HMGN2 molecular weight were detected by Tricine-SDS-PAGE and the mass spectrum. The antimicrobial activity of HMGN2 was detected by agar diffusion test. Results HMGN2 had potent antimicrobial activity against E.coli ML-35p, some extent against E.Coli ATCC 25922 and clinical isolate 54080. However, its was inactive against S.aureus ATCC25923. Conclusion HMGN2 protein is an antimicrobial molecule and it is probably involved in the defensive of the innate immunity.

Key words: Human THP-1 cells, HMGN2, Antimicrobial polypeptide, Isolation and Purification