RESUMEN
Using the membrane-modifying peptide, trichorovin-XIIa (TV-XIIa), which is an 11-residual peptaibol isolated from the fungus Trichoderma viride, we synthesized covalent conjugates of 20-mer oligonucleotide with TV-XIIa to examine the potential use of TV-XIIa in cellular delivery. The results indicated that the conjugates were progressively taken up by human lung carcinoma A549 cells. Next, the antisense effects of the conjugates on p53 protein expression were examined. The p53 expression was significantly decreased by ca. 20-50% in the presence of the conjugates upon treatment with the transfection solution at the concentration of 5 µM.
Asunto(s)
Sistemas de Liberación de Medicamentos , Oligonucleótidos Antisentido/química , Peptaiboles/química , Péptidos , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Microscopía Confocal , Oligonucleótidos Antisentido/farmacología , Peptaiboles/metabolismo , Péptidos/química , Péptidos/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
The biophysical characteristics and channel-forming activity of peptaibols inserted into artificial membranes have been studied over the last 30 years. However, to our knowledge, no studies have addressed directly their behavior in living cells. In this work, a novel strategy has been employed to precisely assess the living cell membrane-penetrating activity of a fluorescein-labeled Aib (alpha-aminoisobutyric acid)-containing peptide derived from a peptaibol, trichorovin-XIIa (TV-XIIa). We have demonstrated for the first time that the peptide containing an unusual amino acid residue, Aib, is taken up by cells via a non endocytic pathway. The replacement of Aib in the TV-XIIa sequence with Ala inhibits the cellular uptake.