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Właściwości koordynacyjne wybranych cyklicznych hormonów peptydowych oraz ich pochodnych

Witak Weronika, Marciniak Aleksandra

Wiadomości Chemiczne

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2021

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[Z] 75, 5-6

799--821

EN

Hormones are a heterogeneous, significant compounds, responsible for proper functioning of living organisms, produced by specialized cells, tissues and glands. Theirs main role is signals transmission to target tissues, responsible for the right working of the whole organism. Dysfunctions of the hormones homeostasis balance lead to disease states [1-3]. Recently, scientists have paid attention to role of the metal ions in the proper synthesis of these compounds and functioning of human body [4]. More and more scientific works explain the complicated roles of metals as beneficial factors that stimulate the conformation of peptides. Metal ions are responsible for biological properties and influence of hormones binding to appropriate receptors, but also adverse factors [4,5]. The search for an answer to the question about the metal - hormone relationship has led to the development of a new, interdisciplinary studies: metalloendocrinology, linking inorganic chemistry with endocrinology [4]. In this work, we present the literature data that relate to metal - peptide hormone interactions. We focused on cyclic hormones with a disulfide bridge and their analogues. In our review we have focused on selected natural cyclic peptide hormones: oxytocin, vasopressin, somatostatin, hepcidin and amylin. The studies on the coordination abilities showed that transition metal ions, such as copper(II), zinc(II) or nickel(II), form stable complexes with described peptides. Metal ions actively participate in many phenomena. They have played role in the formation of amylin aggregates in patients with type 2 diabetes [6]. The high ability to copper(II) by hepcidin may have an effect on its homeostasis [7]. Stable complexes of oxytocin and vasopressin facilitate binding with appropriate receptors for these peptides [8].

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Cyanobacterial hepatotoxins, microcystins and nodularins, in fresh and brackish waters of the Pomeranian Province, Northern Poland

Mazur-Marzec H., Spoof L., Kobos J., Pliński M., Meriluoto J.

Oceanological and Hydrobiological Studies

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2008

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Vol. 37, No.4

3-21

EN

Microcystins (MCs) and structurally related nodularins (NODs) are hepatotoxic cyclic peptides produced by bloom-forming cyanobacteria. These toxins have been implicated in the deaths of wild and domestic animals as well as in incidents of human illness. Cyanobacterial toxins occurring in the fresh and brackish waters of the Pomeranian Province, northern Poland were characterized in this study. Water samples collected from seven lakes in August and September 2005 were analysed by high performance liquid chromatography (HPLC), enzyme linked immunosorbent assay (ELISA) and protein phosphatase inhibition assay (PPIA). Cyanobacterial toxins present in field samples and in an isolated strain of Planktothrix agardhii were also characterized by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). In most of the fresh water samples MC-LR, MC-RR and MC-YR dominated. In the lakes where P. agardhii was most abundant demethylated microcystin variants tentatively identified as [D-Asp3]MC-LR, [D-Asp3]MC-YR and [D-Asp3]MC-RR, were found. Total concentrations of the toxins measured by HPLC ranged from 0.1 žg l-1 to 305.4 žg l-1. Nodularia spumigena bloom samples were collected from brackish waters of the Gulf of Gdańsk, southern Baltic, and LC-ISP-MS/MS of extract from these revealed the presence of two geometrical isomers of linear nodularin and nodularin variant with aspartic acid methyl ester [MeAsp1(OMe)]NOD.

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Further Investigations on the Optical Activity of Aromatic Residues in Cyclolinopeptide A Analogues

Siemion I., Cebrat M., Lisowski M.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 7

955-964

EN

CD spectra of a series in methanol solution were analyzed. It was conformed that the aromatic residue in position 9 contribues to a low extent only to the optical activity of the peptide. However, this phenomenon is not a result of the "edge-to-face" interaction of aromatic side chains but rather of the conformation of the aromatic side chain in position 9.