Yong-Gang Xie

Publications (3)5.42 Total impact

• Article: Effects of Amino Acid Deletion and Substitution on the Chemical Properties, Biological Activities of the Frog Peptide Palustrin-OG1.

  Yong-Gang Xie, Yi-Fan Liu, Chao Luan, Fei-Fei Han, Ren Lai, Denis Groleau, Jie Feng, Yi-Zhen Wang
  [show abstract] [hide abstract]
  ABSTRACT: Palustrin-OG1 (OG1) is a host defense peptide isolated from the frog Odorrana grahami. In this study, we analyzed the chemical properties, antimicrobial activities and cytotoxicities of OG1 and its derivatives to identify the most promising peptide as an antimicrobial agent. By increasing the net positive charge, amphipathicity and decreasing the mean hydrophobicity of OG1, the derivative named as OG2 exerted higher antimicrobial activity against bacteria but lower cytotoxicity against both porcine erythrocytes and peripheral blood mononuclear cells than did OG1 (P<0.01). After substitution of Cys residues of OG2 by Ala or Trp residues, two derivatives named as OG2A and OG2W were less effective against bacteria and induced greater hemolysis than did OG2, indicating the importance of Cys residues. The substitution of the C-terminal Thr of OG2 resulted OG2N, which decreased the cytotoxicity and improved killing kinetics against gram-positive bacteria by the rapid damage of cell wall and membrane.
  Protein and Peptide Letters 10/2012; · 1.94 Impact Factor
• Article: Effects of Thioredoxin, SUMO and Intein on Soluble Fusion Expression of an Antimicrobial Peptide OG2 in Escherichia coli.

  Yong-Gang Xie, Chao Luan, Hai-Wen Zhang, Fei-Fei Han, Jie Feng, Young-Jun Choi, Denis Groleau, Yi-Zhen Wang
  [show abstract] [hide abstract]
  ABSTRACT: OG2 is a modified antimicrobial peptide of Palustrin-OG1 (OG1), which is derived from Odorrana grahami frog. OG2 has shown much higher selective antimicrobial activity and lower hemolytic activity than OG1, indicating OG2 may be a promising antimicrobial agent. In this study, we investigated three fusion partners, including thioredoxin, Mxe GyrA intein, and small ubiquitin-like modifier (SUMO), each fused with OG2, and examined their effects on the expression level and solubility of OG2 in Escherichia coli. The codon-optimized OG2 gene was cloned into pET32a (+) and pTWIN1 for fusion with thioredoxin and Mxe GyrA intein, respectively. In addition, the SUMO-OG2 gene was amplified by splice overlap extension PCR method and was cloned into pET30a (+). All recombinant plasmids were then transformed into E. coli BL21(DE3)pLysS, and the expressed fusion proteins were verified. Upon isopropyl β-D-1-thiogalactopyranoside (IPTG) induction, OG2 fused with thioredoxin (Trx-OG2) showed the highest yield as a soluble fusion protein (50 mg/L), followed by Mxe GyrA intein (44 mg/L) and SUMO (11 mg/L). The thioredoxin-fused protein (Trx-OG2) was then purified by nickel-nitrilotriacetic acid chromatography and desalted by Sephadex G25. The OG2 released by both tobacco etch virus protease and enterokinase from Trx-OG2 showed strong antimicrobial activity against Staphylococcus aureus ATCC25923.
  Protein and Peptide Letters 06/2012; · 1.94 Impact Factor
• Article: Antimicrobial peptides derived from different animals: comparative studies of antimicrobial properties, cytotoxicity and mechanism of action

  Fei-Fei Han, Yi-Fan Liu, Yong-Gang Xie, Yan-Hua Gao, Chao Luan, Yi-Zhen Wang
  [show abstract] [hide abstract]
  ABSTRACT: Animals posses a large variety of antimicrobial peptides (AMPs) that serve as effective components in innate host defenses against microbial infections. These antimicrobial peptides differ in amino acid composition, range of antimicrobial specificities, hemolysis, cytotoxicity and mechanisms of action. This study was designed to evaluate their therapeutic potential of the following six antimicrobial peptides initially found from animals: cecropin P1, indolicidin, LL-37, palustrin-OG1, LFP-20 and LFB-11. Our results indicated that cecropin P1 possessed the most desired biological activity, with fast and potent antimicrobial activity but only slight hemolytic or cytotoxic activity against human cells. Indolicidin was more effective against gram-positive bacteria but with higher hemolytic and cytotoxic activity on human peripheral blood mononuclear cell (PBMCs) (P<0.05). Although LFP-20 and LFB-11 had moderate activity against tested strains and need 30min to kill E. coli, they showed almost no hemolytic and cytotoxic activity towards PBMCs (P<0.01). Indolicidin could form pores of well-defined structure in bacterial membranes whereas lysis of E. coli cells was observed after addition LFB-11 and LL-37 at 1×MIC for 1h. LL-37 treatment could lead to the leakage of entire bacterial cytoplasmic contents. The most obvious phenomenon was protuberant structures on the E. coli cell surface after incubation with LFP-20, cecropin P1 and palustrin-OG1. The results presented here illustrate that AMPs derived from different animals exhibited different antimicrobial characteristics. Because of their potent and broad-spectrum antimicrobial activity, low cytotoxicity towards normal cells, and the unique mechanism of action, these peptides may provide the impetus for the development of novel strategies for the prevention of bacterial infections in animals. KeywordsAnimal antimicrobial peptide–Antimicrobial activity–Hemolysis–Cytotoxicity–Mechanism of action
  World Journal of Microbiology and Biotechnology 04/2012; 27(8):1847-1857. · 1.53 Impact Factor