The antimicrobial peptide Thrombocidin-1 (TC-1) isolated from human blood that derived from NAP-2 by deleting of two amino acids from C-terminal region. In this study， a C-terminal 6 _ His tagged recombinant TC-1 was expressed as a secreted peptide in Pichia pastoris， for the first time. The recombinant P. pastoris was inoculated in to BMMY culture medium， incubation with 5 μl/ml absolute methanol for 72 h at 30 °C. The TC-1 peptide was concentrated with nickel affinity chromatography and electrophoresis on 16% acrylamide gels. The molecular weight of recombinant TC-1 is approximately 8 kDa and under these conditions， the concentration of TC-1 considered 190 μg/ml that determined by the B... More
The antimicrobial peptide Thrombocidin-1 (TC-1) isolated from human blood that derived from NAP-2 by deleting of two amino acids from C-terminal region. In this study， a C-terminal 6 _ His tagged recombinant TC-1 was expressed as a secreted peptide in Pichia pastoris， for the first time. The recombinant P. pastoris was inoculated in to BMMY culture medium， incubation with 5 μl/ml absolute methanol for 72 h at 30 °C. The TC-1 peptide was concentrated with nickel affinity chromatography and electrophoresis on 16% acrylamide gels. The molecular weight of recombinant TC-1 is approximately 8 kDa and under these conditions， the concentration of TC-1 considered 190 μg/ml that determined by the Bradford method. The antimicrobial activity test (Minimum Inhibitory Concentration and Minimum Bactericidal Concentration) was done against: Listeria monocytogenes， Escherichia coli， Klebsiella pneumonia， Staphylococcus aureus， Enterococcus faecalis and Pseudomonas aeruginosa. The growth of these pathogenic bacteria was limited when we used peptide at a concentration of as low as 19.56 μg/ml. Based on DPPH radical scavenging (DPPH-RS) activity and reducing power assays， this peptide showed relatively good antioxidant potential in comparison with standard antioxidant used in this study (BHT). Due to the existence of TC-1 in blood， which makes it safe for human consumption， and the good results of its antimicrobial and antioxidant activity， it can be introduced as a good alternative and a novel effective peptide to food industry for bio-preservation.
