Fusion expression of cecropin B-like antibacterial peptide in Pichia GS115 and its antibacterial mechanism.
OBJECTIVE
To establish an efficient expression system for a fusion protein of glutathione S-transferase and cecropin B (GST-CB) and to clarify the antibacterial mechanism of CB.


RESULTS
The optimal incubation time and methanol concentration for induced expression of CB were 36 h and 1 % w/v, respectively. The yield of GST-CB was 2.2 g/l. The minimum inhibitory concentrations of GST-CB towards Staphylococcus aureus subsp. saprophyticus (ATCC 15305) and Escherichia coli strain CFT073 were 250 and 125 μg/ml, respectively. Notably, mutations of proline 24 (P24) in CB produced a polypeptide without antimicrobial activity.


CONCLUSIONS
The fusion protein GST-CB, which has a broad spectrum antimicrobial activity, can be abundantly expressed in Pichia pastoris GS115, and P24 may be an important amino acid for the antimicrobial activity of GST-CB.
Key Laboratory of Dairy Science Ministry of Education, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin, 150030, China.
Wei
W
Yu
Key Laboratory of Dairy Science Ministry of Education, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin, 150030, China. gaoxj5390@sina.com.
Xue Jun
XJ
Gao
Key Laboratory of Dairy Science Ministry of Education, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin, 150030, China.
Ying
Y
Liu
Key Laboratory of Dairy Science Ministry of Education, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin, 150030, China.
Qi
Q
Wang
D000890:Anti-Infective Agents / Q000378:metabolism / Q000494:pharmacology*; D054807:Cecropins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D015870:Gene Expression; D008826:Microbial Sensitivity Tests; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects
D000890:Anti-Infective Agents; D054807:Cecropins; D011993:Recombinant Fusion Proteins
Antibacterial mechanism; Antibacterial peptide; Cecropin B; Fusion expression; Pichia pastoris GS115