Somatostatin (SST) analogues have aroused the interest of scientists for years. This group of compounds is used in the diagnosis and treatment of neuroendocrine tumors. However, new molecules useful as radiopharmaceuticals in targeted therapy are still searched for. Bicyclic peptides seem to be very interesting in this context. These molecules are associated with beneficial properties. In this work, we present studies on the binding ability of the bicyclic analogue of somatostatin toward copper(II) ions which could potentially be a chelator for copper radionuclides. The research is focused on the analysis of Cu(II) interactions with the metal binding cycle of the ligand and the influence of the receptor binding site on the coordination process. This is a novelty in comparison to the SST analogues used in medicine, where a metal ion is coordinated by a chelator and connected with a bioactive molecule by the linker. In this work we present the first coordination study for bicyclic ligand. Obtained results showed that the complexes with only imidazole donors are characterized by significantly higher stability in comparison to the other peptides.

中文翻译：

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双环生长抑素类似物对Cu(II)离子的结合能力

多年来，生长抑素 (SST) 类似物引起了科学家们的兴趣。这组化合物用于神经内分泌肿瘤的诊断和治疗。然而，仍在寻找在靶向治疗中用作放射性药物的新分子。在这种情况下，双环肽似乎非常有趣。这些分子与有益的特性有关。在这项工作中，我们研究了生长抑素的双环类似物对可能成为铜放射性核素螯合剂的铜 (II) 离子的结合能力。研究重点是分析Cu(II)与配体金属结合循环的相互作用以及受体结合位点对配位过程的影响。与医学中使用的 SST 类似物相比，这是一个新事物，其中金属离子由螯合剂配位并通过接头与生物活性分子连接。在这项工作中，我们提出了双环配体的第一个配位研究。获得的结果表明，与其他肽相比，仅含咪唑供体的复合物具有显着更高的稳定性。