TY - JOUR

T1 - Metabolic cleavage of cell-penetrating peptides in contact with epithelial models

T2 - human calcitonin (hCT)-derived peptides, Tat(47-57) and penetratin(43-58)

AU - Tréhin, Rachel

AU - Nielsen, Hanne Mørck

AU - Jahnke, Heinz-Georg

AU - Krauss, Ulrike

AU - Beck-Sickinger, Annette G.

AU - Merkle, Hans P

PY - 2004

Y1 - 2004

N2 - We assessed the metabolic degradation kinetics and cleavage patterns of some selected CPP (cell-penetrating peptides) after incubation with confluent epithelial models. Synthesis of N-terminal CF [5(6)-carboxyfluorescein]-labelled CPP, namely hCT (human calcitonin)-derived sequences, Tat(47-57) and penetratin(43-58), was through Fmoc (fluoren-9-ylmethoxycarbonyl) chemistry. Metabolic degradation kinetics of the tested CPP in contact with three cell-cultured epithelial models, MDCK (Madin-Darby canine kidney), Calu-3 and TR146, was evaluated by reversed-phase HPLC. Identification of the resulting metabolites of CF-hCT(9-32) was through reversed-phase HPLC fractionation and peak allocation by MALDI-TOF-MS (matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry) or direct MALDI-TOF-MS of incubates. Levels of proteolytic activity varied highly between the investigated epithelial models and the CPP. The Calu-3 model exhibited the highest proteolytic activity. The patterns of metabolic cleavage of hCT(9-32) were similar in all three models. Initial cleavage of this peptide occurred at the N-terminal domain, possibly by endopeptidase activity yielding both the N- and the C-terminal counterparts. Further metabolic degradation was by aminopeptidase, endopeptidase and/or carboxypeptidase activities. In conclusion, when in contact with epithelial models, the studied CPP were subject to efficient metabolism, a prerequisite of cargo release on the one hand, but with potential for premature cleavage and loss of the cargo as well on the other. The results, particularly on hCT(9-32), may be used as a template to suggest structural modifications towards improved CPP performance.

AB - We assessed the metabolic degradation kinetics and cleavage patterns of some selected CPP (cell-penetrating peptides) after incubation with confluent epithelial models. Synthesis of N-terminal CF [5(6)-carboxyfluorescein]-labelled CPP, namely hCT (human calcitonin)-derived sequences, Tat(47-57) and penetratin(43-58), was through Fmoc (fluoren-9-ylmethoxycarbonyl) chemistry. Metabolic degradation kinetics of the tested CPP in contact with three cell-cultured epithelial models, MDCK (Madin-Darby canine kidney), Calu-3 and TR146, was evaluated by reversed-phase HPLC. Identification of the resulting metabolites of CF-hCT(9-32) was through reversed-phase HPLC fractionation and peak allocation by MALDI-TOF-MS (matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry) or direct MALDI-TOF-MS of incubates. Levels of proteolytic activity varied highly between the investigated epithelial models and the CPP. The Calu-3 model exhibited the highest proteolytic activity. The patterns of metabolic cleavage of hCT(9-32) were similar in all three models. Initial cleavage of this peptide occurred at the N-terminal domain, possibly by endopeptidase activity yielding both the N- and the C-terminal counterparts. Further metabolic degradation was by aminopeptidase, endopeptidase and/or carboxypeptidase activities. In conclusion, when in contact with epithelial models, the studied CPP were subject to efficient metabolism, a prerequisite of cargo release on the one hand, but with potential for premature cleavage and loss of the cargo as well on the other. The results, particularly on hCT(9-32), may be used as a template to suggest structural modifications towards improved CPP performance.

KW - Amino Acid Sequence

KW - Animals

KW - Biotransformation

KW - Calcitonin

KW - Cell Line

KW - Chromatography, High Pressure Liquid

KW - Dogs

KW - Drug Carriers

KW - Epithelial Cells

KW - Gene Products, tat

KW - Homeodomain Proteins

KW - Humans

KW - Kinetics

KW - Molecular Sequence Data

KW - Molecular Weight

KW - Peptide Fragments

KW - Structure-Activity Relationship

KW - tat Gene Products, Human Immunodeficiency Virus

U2 - 10.1042/BJ20040238

DO - 10.1042/BJ20040238

M3 - Journal article

C2 - 15193145

VL - 382

SP - 945

EP - 956

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - Pt 3

ER -