Expression, Purification, and Antibacterial Activity of Bovine Lactoferrampin–Lactoferricin in Pichia pastoris Xiang-Shan Tang & Zhi-Ru Tang & Sheng-Ping Wang & Ze-Meng Feng & Dong Zhou & Tie-Jun Li & Yu-Long Yin Received: 25 July 2011 /Accepted: 7 November 2011 / Published online: 23 November 2011 # Springer Science+Business Media, LLC 2011 Abstract Bovine lactoferrampin (LFA) and bovine lactoferricin (LFC) are two antimicro- bial peptides located in the N 1 domain of bovine lactoferrin. The bactericidal activity of the fused peptide LFA–LFC is stronger than that of either LFA or LFC. The high cost of peptide production from either native digestion or chemical synthesis limits the clinical application of antimicrobial peptides. The expression of recombinant peptides in yeast may be an effective alternative. In the current study, the expression, purification, and antibacterial activity of LFA–LFC using the Pichia pastoris expression system are reported. The linearized expression vector pPICZaA–LFA–LFC was transformed into P. pastoris KM71 by electroporation, and positive colonies harboring the target genes were screened out and used for fermentation. The recombinant LFA–LFC peptide was purified via two-step column chromatography and identified by tricine–sodium dodecyl sulfate–polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results indicate that P. pastoris is a suitable system for secreting LFA–LFC. The fermentation supernate and the purified LFA–LFC show high antimicrobial activities. The current study is the first to report on the expression and purification of LFA–LFC in P. pastoris and may have potential practical applications in microbial peptide production. Appl Biochem Biotechnol (2012) 166:640–651 DOI 10.1007/s12010-011-9455-0 X.-S. Tang : S.-P. Wang : Z.-M. Feng : D. Zhou : T.-J. Li : Y.-L. Yin Research Center for Healthy Breeding of Livestock and Poultry, Institute of Subtropical Agriculture, CAS, Changsha, Hunan 410125, China X.-S. Tang : S.-P. Wang : Z.-M. Feng : D. Zhou : T.-J. Li : Y.-L. Yin Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, CAS, Changsha, Hunan 410125, China Z.-R. Tang College of Animal Science and Technology, Southwest University, Chongqing 400715, China X.-S. Tang : S.-P. Wang : Z.-M. Feng : D. Zhou Graduate School of Chinese Academy of Sciences, Beijing 100049, China Y.-L. Yin (*) Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha 410125, China e-mail: yinyulong@isa.ac.cn