title: The orientation of BN-related peptides adsorbed on SERS-active silver nanoparticles: comparison with a silver electrode surface.
abstract: We used surface-enhanced Raman scattering (SERS) to characterize the adsorption behavior of bombesin (BN) and five BN-related peptides, including phyllolitorin, [Leu(8)]phyllolitorin, neuromedin C (NMC), neuromedin B (NMB), and PG-L (Pseudophryne guntheri), in a silver colloidal solution. Our experiments show that the pyrrole coring of the Trp and aromatic ring of Phe of these peptides are preferentially adsorbed on silver nanoparticles. However, the geometry of the rings and the strength of the interactions with this surface vary among peptides. Additionally, these peptides are weakly coordinated to the colloidal silver surface through the CO fragment of a peptide bond, between Gln/Leu/His and Trp residues, and CNC and SC fragments. Also, using the recently reported SERS spectra of these peptides immobilized onto an electrochemically roughened silver electrode surface, we demonstrate substrate-induced changes in the adsorption behavior of these peptides. Comparative analysis indicates that the interactions between peptides and the enhancing surfaces depend strongly on the geometry of the Trp, CONH, and SC fragments of these biomolecules etched on the surfaces.
authors.affiliation: Regional Laboratory of Physicochemical Analysis and Structural Research, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland. podstawk@chemia.uj.edu.pl
authors.forename: Edyta
authors.initials: E
authors.lastname: Podstawka
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Proniewicz
mesh_terms: D000327:Adsorption; D000818:Animals; D001001:Anura; D001839:Bombesin / Q000031:analogs & derivatives* / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D004566:Electrodes; D053758:Nanoparticles / Q000737:chemistry*; D015287:Neurokinin B / Q000031:analogs & derivatives* / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods; D013499:Surface Properties
chemical_list: D003102:Colloids; D009842:Oligopeptides; D010446:Peptide Fragments; D012834:Silver; C040794:neuromedin C; D015287:Neurokinin B; C038393:neuromedin B; C043155:phyllolitorin; D001839:Bombesin; D011761:Pyrrolidonecarboxylic Acid