Podstawka Edyta
Laser Raman Laboratory, Regional Laboratory of Physicochemical Analysis and Structural Research, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland.
Biopolymers. 2008 Jun;89(6):506-21. doi: 10.1002/bip.20909.
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-Phe12]BN, [Tyr4]BN, and [Lys3]BN) or two ([Tyr4,D-Phe12]BN, [D-Phe12,Leu14]BN, and [Leu13-(R)-Leu14]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 Trp8, the C==O 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 --CH2-- of [D-Phe12]BN, [Tyr4,D-Phe12]BN, [D-Phe12,Leu14]BN, [Leu13-(R)-Leu14]BN, and [Lys3]BN with the silver surface perturbed the vertical orientation of the Trp8 indole ring on this surface. Hence, the indole ring adopted a close to perpendicular orientation on the silver surface for BN and [Tyr4]BN, only.
这项工作基于如下所述的红外吸收和拉曼光谱结果，描述了蛙皮素（BN）及其类似物的分子结构。在这些类似物中，肽链内的一个（[D-苯丙氨酸12]BN、[酪氨酸4]BN和[赖氨酸3]BN）或两个（[酪氨酸4,D-苯丙氨酸12]BN、[D-苯丙氨酸12,亮氨酸14]BN和[亮氨酸13-(R)-亮氨酸14]BN）氨基酸残基被合成氨基酸取代，从而产生了蛙皮素拮抗剂，这些拮抗剂可用于癌症治疗。还利用表面增强拉曼散射（SERS）研究了BN及其类似物的振动光谱差异和变化，当这些肽与靶蛋白相互作用时，它们附着在经电化学粗糙化处理的银表面。这项工作探索了利用SERS对锚定在宏观银表面的分子进行研究，以探究这些肽与蛋白质受体的相互作用。此处呈现的结果表明，所有肽均通过吲哚环、色氨酸8的亚甲基、C==O片段和酰胺键与宏观银表面配位；然而，这些片段在经电化学粗糙化处理的银表面上的取向以及与该表面相互作用的强度，每种肽略有不同。例如，[D-苯丙氨酸12]BN、[酪氨酸4,D-苯丙氨酸12]BN、[D-苯丙氨酸12,亮氨酸14]BN、[亮氨酸13-(R)-亮氨酸14]BN和[赖氨酸3]BN的–CH2–与银表面的相互作用扰乱了色氨酸8吲哚环在该表面上的垂直取向。因此，仅BN和[酪氨酸4]BN的吲哚环在银表面呈接近垂直的取向。
