Peptide-Conjugated Ultrasmall Gold Nanoparticles (2 nm) for Selective Protein Targeting

Author(s)

Ruks, Tatjana ^{[1, 2]} ; Loza, Kateryna ^{[1, 2]} ; Heggen, Marc ^[3] ; Prymak, Oleg ^{[1, 2]} ; Sehnem, Andre Luiz ^[4] ; Oliveira, Cristiano L. P. ^[4] ; Bayer, Peter ^[5] ; Beuck, Christine ^[5] ; Epple, Matthias ^{[1, 2]}

Affiliation

^[1] Univ Duisburg Essen, Inorgan Chem, D-45117 Essen - Germany

^[2] Univ Duisburg Essen, Ctr Nanointegrat Duisburg Essen CeNIDE, D-45117 Essen - Germany

^[3] Forschungszentrum Julich, Ernst Ruska Ctr Microscopy & Spect Electrons, D-52425 Julich - Germany

^[4] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo - Brazil

^[5] Univ Duisburg Essen, Ctr Med Biotechnol ZMB, Dept Struct & Med Biochem, D-45117 Essen - Germany

• Document type: Journal article
• Source: ACS APPLIED BIO MATERIALS; v. 4, n. 1, p. 945-965, JAN 18 2021.
• Web of Science Citations: 0

Abstract

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 H-1 NMR spectroscopy, showing about 150 peptide molecules conjugated to each nanoparticle. The interaction between the peptide-decorated nanoparticles with hPin1-WW was probed by H-1-N-15-HSQC NMR titration, fluorescence polarization spectroscopy (FP), and isothermal titration calorimetry (ITC). The particles showed a similar binding (K-D = 10-20 mu M) compared to the dissolved peptides (K-D = 10-30 mu M). 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-fiinctionalized 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. (AU)

• FAPESP's process: 19/10433-8 - Simulation and Structural Modeling of Oriented Liquid Crystals using Small-Angle Scattering Methodsng
• Grantee: André Luiz Sehnem
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/06750-8 - Probing the non-covalent interaction of ultrasmall gold nanoparticles with selected proteins
• Grantee: Cristiano Luis Pinto de Oliveira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/16092-5 - Investigating colloidal systems by scattering methods
• Grantee: Cristiano Luis Pinto de Oliveira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/24531-3 - Structural and biophysics properties of native and modified lipoproteins
• Grantee: Antonio Martins Figueiredo Neto
• Support Opportunities: Research Projects - Thematic Grants