Production of bioactive human alpha-defensin 5 in Pichia pastoris.

Human alpha-defensin 5 (HD5), a small cationic peptide, is expressed in Paneth cell granules of small intestinal crypts. HD5 exhibits high antimicrobial activity against a broad spectrum of pathogenic agents, including bacteria, fungi, and viruses. In this study, the constitutive expression of HD5 antimicrobial peptide was achieved using the methylotrophic yeast, Pichia pastoris (P.