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Investigation of molecular structure of bombesin and its modified analogues nonadsorbed and adsorbed on electrochemically roughened silver surface
Author(s) -
Podstawka Edyta
Publication year - 2008
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20909
Subject(s) - chemistry , bombesin , peptide , amide , molecule , raman scattering , indole test , raman spectroscopy , crystallography , amino acid , peptide bond , stereochemistry , receptor , organic chemistry , neuropeptide , biochemistry , physics , optics
This work describes the molecular structure of bombesin (BN) and its analogs on the basis of the absorption infrared and Raman results described below. In these analogues is replaced one ([D‐Phe 12 ]BN, [Tyr 4 ]BN, and [Lys 3 ]BN) or two ([Tyr 4 ,D‐Phe 12 ]BN, [D‐Phe 12 ,Leu 14 ]BN, and [Leu 13 ‐®‐Leu 14 ]BN) amino acid residues within the peptide chain with a synthetic amino acid, creating antagonists to bombesin, which are useful in the treatment of cancer. It is also used surface enhanced Raman scattering (SERS) to study the differences and changes in the vibrational spectra of BN and its analogs, which were attached to an electrochemically roughened silver surface as these peptides interacted with target proteins. This work explores the use of SERS for molecules anchored to a macroscopic silver surface to interrogate the interaction of these peptides with protein receptors. The results presented here show that all peptides coordinate to the macroscopic silver surface through an indole ring and the methylene group of Trp 8 , the CO fragment, and an amide bond; however, the orientation of these fragments on the electrochemically roughened silver surface and the strength of the interactions with this surface is slightly different for each peptide. For example, the interaction of CH 2 of [D‐Phe 12 ]BN, [Tyr 4 ,D‐Phe 12 ]BN, [D‐Phe 12 ,Leu 14 ]BN, [Leu 13 ‐®‐Leu 14 ]BN, and [Lys 3 ]BN with the silver surface perturbed the vertical orientation of the Trp 8 indole ring on this surface. Hence, the indole ring adopted a close to perpendicular orientation on the silver surface for BN and [Tyr 4 ]BN, only. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 506–521, 2008. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com