Raman and surface-enhanced Raman spectroscopy investigation of vasopressin analogues containing 1-aminocyclohexane-1-carboxylic acid residue.
Raman and surface-enhanced Raman spectroscopy investigation of vasopressin analogues containing 1-aminocyclohexane-1-carboxylic acid residue.
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DOI：
10.1002/bip.20545
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发表时间：
2006-10
期刊：
影响因子：
2.9
通讯作者：
E. Podstawka;E. Sikorska;L. Proniewicz;B. Lammek
中科院分区：
文献类型：
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作者：
E. Podstawka;E. Sikorska;L. Proniewicz;B. Lammek
本工作采用拉曼光谱（RS）对[Arg 8]加压素（AVP）及其[Acc 2，D-Arg 8]AVP、[Acc 3]AVP和[Cpa 1，Acc 3]AVP类似物的分子结构进行了表征。已经提出了RS频带分配。为了确定吸附在胶体银表面上的上述化合物的吸附机理，测量了表面增强拉曼光谱（Sers）。Sers光谱用于确定[校正]研究肽的吸附官能团及其在银表面上的取向的相对接近度。AVP和[Acc 3]AVP Sers光谱（Acc：1-aminocyclohexane-1-carboxylic acid）显示L-酪氨酸（Tyr）远离金属表面，而[Cpa 1，Acc 3]AVP光谱（Cpa：1-mercaptohexaneacetic acid）提供了Tyr与银表面相互作用的证据。这些结果表明，[校正]的酪氨酸离子化的酚基的结合可能是负责类似物的选择性。我们发现AVP和[Acc 2，D-Arg 8]AVP的L-苯丙氨酸（Phe）的芳香环与银表面相互作用。这种相互作用的强度对于[Acc 2，D-Arg 8]AVP比对于AVP弱得多。这可能是由于Phe环和银表面之间的距离较长，或者由于Phe环朝向表面的几乎垂直取向。AVP、[Acc 2，D-Arg 8]AVP和[Acc 3]AVP的L-谷氨酰胺[校正]（Gln）或L-天冬酰胺[校正]（Asn）的羰基与银表面牢固结合。我们还发现，所有肽通过二硫桥的硫原子吸附在银表面上，采用“GGG”构象，除了[Cpa 1，Acc 3]AVP，其接受“TGG”几何构型。
In this work, Raman spectroscopy (RS) was employed to characterize molecular structures of [Arg8]vasopressin (AVP) and its [Acc2,D-Arg8]AVP, [Acc3]AVP, and [Cpa1, Acc3]AVP analogues. The RS band assignments have been proposed. To determine the mechanism of adsorption of the above-mentioned compounds adsorbed on a colloidal silver surface, surface-enhanced Raman spectra (SERS) were measured. The SERS spectra were used to determine relative proximity of the adsorbed functional groups of [corrected] investigated peptides and their orientation on the silver surface. The AVP and [Acc3]AVP SERS spectra (Acc: 1-aminocyclohexane-1-carboxylic acid) show that the L-tyrosine (Tyr) lies far from the metal surface, whereas the [Cpa1,Acc3]AVP spectrum (Cpa: 1-mercaptocyclohexaneacetic acid) provides evidence that Tyr interacts with the silver surface. These results suggest that [corrected] the binding of the Tyr-ionized phenolic group might be responsible for the selectivity of the analogues. We show that the aromatic ring of L-phenylalanine (Phe) of AVP and [Acc2,D-Arg8]AVP interacts with the silver surface. The strength of this interaction is considerably weaker for [Acc2,D-Arg8]AVP than for AVP. This might be due either to a longer distance between the Phe ring and the silver surface, or to the almost perpendicular orientation of the Phe ring towards the surface. The carbonyl group of the L-glutamine [corrected] (Gln) or L-asparagine [corrected](Asn) of AVP, [Acc2,D-Arg8]AVP, and [Acc3]AVP is strongly bound to the silver surface. We have also found that all peptides adsorb on the silver surface via sulfur atoms of the disulfide bridge, adopting a "GGG" conformation, except [Cpa1,Acc3]AVP, which accepts a "TGG" geometry.