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Na publikacji autorka Proniewicz Edyta podpisana jako Podstawka‐Proniewicz Edyta.
language:
English
journal language:
English
abstract in English:
Kinetensin (KN) and its amino acids 1-8 fragment ([des-Leu$^{9}$]KN), neuromedin N (NMN), and xenopsin (XP) and its two analogs
(XP-1 and XP-2) belong to the neurotensin family of peptides and are known to stimulate the growth of human tumors. In this
work, we report Fourier transform-Raman and surface-enhanced Raman scattering (SERS) studies of these peptides and
discuss their structures, orientation, and mode of adsorption onto a highly specific, electrochemically roughened SERS-active
Ag electrode that is characterized by the formation of a 50-150nm Ag island on its surface. We show that the investigated
peptides bind preferentially to this surface by substantial electronic overlap between the metal surface and the
$\pi$-orbitals
of the benzene rings of the Phe, Tyr, and Trp residues, which forces them to take parallel or almost parallel orientations
with respect to the surface. In addition, the
-$CH_{2}$-,-$CNH_{2}$, and -COO$^{-}$ molecular fragments are involved in interactions with
(binding to or in close proximity with) the Ag surface. The SERS data show that the adsorption modes in each of these cases
are very similar. In addition, we show that the specific differences in the amino acid sequences do not significantly affect the
orientation of the investigated peptides on the Ag substrate. This result implies that the
N
-termini of the neurotensin-family
peptides do not influence the mode for adsorption onto the Ag substrates.
keywords in English:
surface-enhanced Raman scatterin, kinetensin, neurotensin-family peptides, neuromedin N, xenopsin