S4₁₃-PV cell-penetrating peptide forms nanoparticle-like structures to gain entry into cells

TY - JOUR

T1 - S413-PV cell-penetrating peptide forms nanoparticle-like structures to gain entry into cells

AU - Padari, Kärt

AU - Koppel, Kaida

AU - Lorents, Annely

AU - Hällbrink, Mattias

AU - Mano, Miguel

AU - Pedroso De Lima, Maria C.

AU - Pooga, Margus

PY - 2010/4/21

Y1 - 2010/4/21

N2 - Despite increasing interest in cell-penetrating peptides (CPPs) as carriers for drugs and in gene therapy, the current understanding of their exact internalization mechanism is still far from complete. The cellular translocation of CPPs and their payloads has been mostly described by fluorescence- and activity-based methods, leaving the more detailed characterization at the ultrastructural level almost out of attention. Herein, we used transmission electron microscopy to characterize the membrane interaction and internalization of a cell-penetrating peptide S413-PV. We demonstrate that S4 13-PV peptide forms spherical nanoparticle-like regular structures upon association with cell surface glycosaminoglycans on the plasma membrane. Insertion of S413-PV particles into plasma membrane induces disturbances and leads to the vesicular uptake of peptides by cells. We propose that for efficient cellular translocation S413-PV peptides have to assemble into particles of specific size and shape. The spherical peptide particles are not dissociated in intracellular vesicles but often retain their organization and remain associated with the membrane of vesicles, destabilizing them and promoting the escape of peptides into cytosol. Lowering the temperature and inhibition of dynamins activity reduce the internalization of S4 13-PV peptides, but do not block it completely. Our results provide an ultrastructural insight into the interaction mode of CPPs with the plasma membrane and the distribution in cells, which might help to better understand how CPPs cross the biological membranes and gain access into cells.

AB - Despite increasing interest in cell-penetrating peptides (CPPs) as carriers for drugs and in gene therapy, the current understanding of their exact internalization mechanism is still far from complete. The cellular translocation of CPPs and their payloads has been mostly described by fluorescence- and activity-based methods, leaving the more detailed characterization at the ultrastructural level almost out of attention. Herein, we used transmission electron microscopy to characterize the membrane interaction and internalization of a cell-penetrating peptide S413-PV. We demonstrate that S4 13-PV peptide forms spherical nanoparticle-like regular structures upon association with cell surface glycosaminoglycans on the plasma membrane. Insertion of S413-PV particles into plasma membrane induces disturbances and leads to the vesicular uptake of peptides by cells. We propose that for efficient cellular translocation S413-PV peptides have to assemble into particles of specific size and shape. The spherical peptide particles are not dissociated in intracellular vesicles but often retain their organization and remain associated with the membrane of vesicles, destabilizing them and promoting the escape of peptides into cytosol. Lowering the temperature and inhibition of dynamins activity reduce the internalization of S4 13-PV peptides, but do not block it completely. Our results provide an ultrastructural insight into the interaction mode of CPPs with the plasma membrane and the distribution in cells, which might help to better understand how CPPs cross the biological membranes and gain access into cells.

UR - http://www.scopus.com/inward/record.url?scp=77951285705&partnerID=8YFLogxK

U2 - 10.1021/bc900577e

DO - 10.1021/bc900577e

M3 - Article

C2 - 20205419

AN - SCOPUS:77951285705

SN - 1043-1802

VL - 21

SP - 774

EP - 783

JO - Bioconjugate Chemistry

JF - Bioconjugate Chemistry

IS - 4

ER -