TY - JOUR
T1 - A new peptide motif present in the protective antigen of anthrax toxin exerts its efficiency on the cellular uptake of liposomes and applications for a dual-ligand system
AU - Kibria, Golam
AU - Hatakeyama, Hiroto
AU - Harashima, Hideyoshi
N1 - Funding Information:
This study was supported by grants from the Special Education and Research Expenses of the Ministry of Education, Culture, Sports, Science and Technology of Japan. The authors also wish to thank Dr. Milton S. Feather for his helpful advice in writing the English manuscript.
PY - 2011/6/30
Y1 - 2011/6/30
N2 - Protective antigen (PA) is a nontoxic protein present in anthrax toxin. Domain 4 of PA (PA-D4) acts as a receptor binding site for tumor endothelial marker 8 (TEM8). In this study, KYND motif from PA-D4 was utilized as a ligand against TEM8. The efficiency of KYND motif on cellular association was assessed by evaluating the cellular uptake of PEGylated liposomes (PEG-LPs) in TEM8 positive and negative cells. The peptide was attached on the top of the PEG of PEG-LP. Compared to PEG-LP, KYND modified PEG-LP (KYND-PEG-LP) enhanced the cellular uptake to a greater extent in all cell lines. Based on the inhibition assay, no receptor involvement was observed in the cellular association of KYND-PEG-LP, suggesting that KYND motif functions as a cell penetrating peptide (CPP) which facilitated the internalization of PEG-LP via clathrin mediated endocytosis pathway. Further enhancement of cellular uptake was observed when KYND-PEG-LP was combined with octaarginine (R8) on the surface of lipid membrane as dual-CPP ligand formulation, however, when PEG-LP combined with only R8, only negligible enhancement was observed. These findings suggest that two CPP ligands act in a synergistic fashion; therefore the dual-CPP ligand based liposomal formulation can be assumed to be an effective delivery system.
AB - Protective antigen (PA) is a nontoxic protein present in anthrax toxin. Domain 4 of PA (PA-D4) acts as a receptor binding site for tumor endothelial marker 8 (TEM8). In this study, KYND motif from PA-D4 was utilized as a ligand against TEM8. The efficiency of KYND motif on cellular association was assessed by evaluating the cellular uptake of PEGylated liposomes (PEG-LPs) in TEM8 positive and negative cells. The peptide was attached on the top of the PEG of PEG-LP. Compared to PEG-LP, KYND modified PEG-LP (KYND-PEG-LP) enhanced the cellular uptake to a greater extent in all cell lines. Based on the inhibition assay, no receptor involvement was observed in the cellular association of KYND-PEG-LP, suggesting that KYND motif functions as a cell penetrating peptide (CPP) which facilitated the internalization of PEG-LP via clathrin mediated endocytosis pathway. Further enhancement of cellular uptake was observed when KYND-PEG-LP was combined with octaarginine (R8) on the surface of lipid membrane as dual-CPP ligand formulation, however, when PEG-LP combined with only R8, only negligible enhancement was observed. These findings suggest that two CPP ligands act in a synergistic fashion; therefore the dual-CPP ligand based liposomal formulation can be assumed to be an effective delivery system.
KW - Anthrax toxin
KW - Cell penetrating peptide
KW - Dual-ligand
KW - Liposomes
KW - Tumor endothelial marker 8
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U2 - 10.1016/j.ijpharm.2011.03.010
DO - 10.1016/j.ijpharm.2011.03.010
M3 - Article
C2 - 21414394
AN - SCOPUS:79957482249
SN - 0378-5173
VL - 412
SP - 106
EP - 114
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
IS - 1-2
ER -