Tachyplesin: Difference between revisions
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TP-I has high affinity to negatively charged cell membrane containing LPS and also has ability to permeabilize the cell membrane of pathogens. Docking model suggests strong interaction between cationic residues of TP-I with phosphate group and saccharides of LPS. Also, interaction between hydrophobic residues of TP-I with acyl chains of LPS was observed which strengthens the TP-I/LPS interaction<ref name=Hong>Hong, Jun, et al. "Mechanism of Tachyplesin I injury to bacterial membranes and intracellular enzymes, determined by laser confocal scanning microscopy and flow cytometry." Microbiological research (2014)</ref>. Ultimately, binding of TP-I/LPS neutralizes LPS, which is widely considered as endotoxin, and disrupts membrane function. | TP-I has high affinity to negatively charged cell membrane containing LPS and also has ability to permeabilize the cell membrane of pathogens. Docking model suggests strong interaction between cationic residues of TP-I with phosphate group and saccharides of LPS. Also, interaction between hydrophobic residues of TP-I with acyl chains of LPS was observed which strengthens the TP-I/LPS interaction<ref name=Hong>Hong, Jun, et al. "Mechanism of Tachyplesin I injury to bacterial membranes and intracellular enzymes, determined by laser confocal scanning microscopy and flow cytometry." Microbiological research (2014)</ref>. Ultimately, binding of TP-I/LPS neutralizes LPS, which is widely considered as endotoxin, and disrupts membrane function. | ||
In addition to LPS binding, footpriting analysis has revealed the binding of TP-I to DNA by interacting specifically in minor groove of DNA duplex. The interaction between TP-I and DNA is contributed by secondary structure of the peptide which contains an antiparallel beta-sheet constrained by two disulfide bridges and connected by β-turn <ref name=Yonezawa>PMID:1372516</ref>. | In addition to LPS binding, footpriting analysis has revealed the binding of TP-I to DNA by interacting specifically in minor groove of DNA duplex. The interaction between TP-I and DNA is contributed by secondary structure of the peptide which contains an antiparallel beta-sheet constrained by two disulfide bridges and connected by β-turn <ref name=Yonezawa>PMID:1372516</ref>. TP-I on binding to DNA and RNA, inhibits the synthesis of macromolecules. | ||
In summary, three processes might happen upon TP-I exposure: (1) Bacterial cell membranes are penetrated without disruption of the membrane and the peptide reaches the inner structures of the cell, damaging critical intracellular targets and interfering with intracellular functions and normal metabolism. (2) Pores are formed in the cell wall, causing leakage of intracellular content, leading to cell death. (3) DNA, RNA or protein synthesis are inhibited, killing the bacteria.<ref name=Hong>Hong, Jun, et al. "Mechanism of tachyplesin I injury to bacterial membranes and intracellular enzymes, determined by laser confocal scanning microscopy and flow cytometry." Microbiological research (2014)</ref>. | In summary, three processes might happen upon TP-I exposure: (1) Bacterial cell membranes are penetrated without disruption of the membrane and the peptide reaches the inner structures of the cell, damaging critical intracellular targets and interfering with intracellular functions and normal metabolism. (2) Pores are formed in the cell wall, causing leakage of intracellular content, leading to cell death. (3) DNA, RNA or protein synthesis are inhibited, killing the bacteria.<ref name=Hong>Hong, Jun, et al. "Mechanism of tachyplesin I injury to bacterial membranes and intracellular enzymes, determined by laser confocal scanning microscopy and flow cytometry." Microbiological research (2014)</ref>. | ||
