%0 Journal Article
%A Ruks, Tatjana
%A Loza, Kateryna
%A Heggen, Marc
%A Prymak, Oleg
%A Sehnem, Andre Luiz
%A Oliveira, Cristiano L. P.
%A Bayer, Peter
%A Beuck, Christine
%A Epple, Matthias
%T Peptide-Conjugated Ultrasmall Gold Nanoparticles (2 nm) for Selective Protein Targeting
%J ACS applied bio materials
%V 4
%N 1
%@ 2576-6422
%C Washington, DC
%I ACS Publications
%M FZJ-2021-01676
%P 945 - 965
%D 2021
%X Ultrasmall gold nanoparticles with a metallic core diameter of 2 nm were surface-conjugated with peptides that selectively target epitopes on the surface of the WW domain of the model protein hPin1 (hPin1-WW). The binding to the gold surface was accomplished via the thiol group of a terminal cysteine. The particles were analyzed by NMR spectroscopy, high-resolution transmission electron microscopy, and differential centrifugal sedimentation. The surface loading was determined by conjugating a FAM-labeled peptide, followed by UV–vis spectroscopy, and by quantitative 1H NMR spectroscopy, showing about 150 peptide molecules conjugated to each nanoparticle. The interaction between the peptide-decorated nanoparticles with hPin1-WW was probed by 1H–15N-HSQC NMR titration, fluorescence polarization spectroscopy (FP), and isothermal titration calorimetry (ITC). The particles showed a similar binding (KD = 10–20 μM) compared to the dissolved peptides (KD = 10–30 μM). Small-angle X-ray scattering (SAXS) showed that the particles were well dispersed and did not agglomerate after the addition of hPin1-WW (no cross-linking by the protein). Each nanoparticle was able to bind about 20 hPin1-WW protein molecules. An unspecific interaction with hPin1 was excluded by the attachment of a nonbinding peptide to the nanoparticle surface. The uptake by cells was studied by confocal laser scanning microscopy. The peptide-functionalized nanoparticles penetrated the cell membrane and were located in the cytosol. In contrast, the dissolved peptide did not cross the cell membrane. Peptide-functionalized nanoparticles are promising agents to target proteins inside cells.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000643599900072
%R 10.1021/acsabm.0c01424
%U https://juser.fz-juelich.de/record/891697