RESUMO
Cell-penetrating peptides (CPPs) are promising delivery vehicles. These short peptides can transport wide range of cargos into cells, although their usage has often limitations. One of them is the endosomatic internalisation and thus the vesicular entrapment. Modifications which increases the direct delivery into the cytosol is highly researched area. Among the oligoarginines the longer ones (n > 6) show efficient internalisation and they are well-known members of CPPs. Herein, we describe the modification of tetra- and hexaarginine with (4-((4-(dimethylamino)phenyl)azo)benzoyl) (Dabcyl) group. This chromophore, which is often used in FRET system increased the internalisation of both peptides, and its effect was more outstanding in case of hexaarginine. The modified hexaarginine may enter into cells more effectively than octaarginine, and showed diffuse distribution besides vesicular transport already at low concentration. The attachment of Dabcyl group not only increases the cellular uptake of the cell-penetrating peptides but it may affect the mechanism of their internalisation. Their conjugates with antitumor drugs were studied on different cells and showed antitumor activity.
Assuntos
Antineoplásicos/farmacologia , Cátions/química , Peptídeos Penetradores de Células/farmacologia , Neoplasias/patologia , Oligopeptídeos/química , Peptídeos/química , p-Dimetilaminoazobenzeno/análogos & derivados , Antineoplásicos/química , Proliferação de Células , Peptídeos Penetradores de Células/química , Humanos , Neoplasias/tratamento farmacológico , Células Tumorais Cultivadas , p-Dimetilaminoazobenzeno/químicaRESUMO
Marked promotion of membrane permeation of a cell-penetrating peptide, octaarginine (R8), was attained by attachment to a single 2,2'-dipicolylamine moiety (DPA-R8) that forms 1:1 complexes with metal ions. Studies using giant unilamellar vesicles demonstrated that DPA targets phospholipids and enhances R8 binding to the membranes in the presence of metal ions. While DPA/Zn(II) complex has been most frequently employed for chelate formation with phosphates, Ni(II) had the most prominent effect on the membrane binding and penetration of DPA-R8. Facile cytosolic distribution of DPA-R8 was also attained in a few minutes in the presence of Ni(II). Analysis of the cellular uptake methods of DPA-R8/Ni(II) suggested the involvement of direct permeation through cell membrane without the use of endocytosis. The applicability of this system to the intracellular delivery of bioactive compounds was exemplified using a peptidomimetic farnesyltransferase inhibitor, FTI277.
Assuntos
Peptídeos Penetradores de Células/metabolismo , Complexos de Coordenação/metabolismo , Portadores de Fármacos/metabolismo , Oligopeptídeos/metabolismo , Aminas/química , Aminas/metabolismo , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Peptídeos Penetradores de Células/química , Complexos de Coordenação/química , Portadores de Fármacos/química , Endocitose , Células HeLa , Humanos , Metionina/administração & dosagem , Metionina/análogos & derivados , Metionina/farmacocinética , Oligopeptídeos/química , Ácidos Picolínicos/química , Ácidos Picolínicos/metabolismo , Zinco/química , Zinco/metabolismoRESUMO
An on-cell aptamer sensor has the potential to reveal cell-cell communications by signalling molecules. We attempted to design new fluorescent aptamer sensors for the sensing of IFN-γ and adenine compounds on cells. BODIPY-labeled external quencher-free aptamer sensors have allowed a turn-on detection of the target molecule with improved off/on efficiency.