Wroc.pl (V.D.); [email protected] (R.
Wroc.pl (V.D.); [email protected] (R.W.) Correspondence: [email protected]; Tel.: 48-71-375-Citation: Stokowa-Soltys, K.; Wojtkowiak, K.; Dzyhovskyi, V.; Wieczorek, R. Impact of copper(II) Ion Binding by Porin P1 Precursor Fragments from Fusobacterium nucleatum on DNA Degradation. Int. J. Mol. Sci. 2021, 22, 12541. https://doi.org/10.3390/ ijms222212541 Academic Editor: Giovanni Natile Received: 20 October 2021 Accepted: 18 November 2021 Published: 21 NovemberAbstract: Fusobacterium nucleatum is among the most notorious species involved in colorectal cancer. It was reported that many outer membrane proteins (OMP) are actively involved in carcinogenesis. In this paper, the structure and stability of particular complexes, at the same time as DNA cleavage and ROS generation by fragments of OMP, were investigated employing experimental and theoretical methods. Mass spectrometry, potentiometry, UV-Vis, CD, EPR, gel electrophoresis and calculations at the density functional theory (DFT) level were applied. Two consecutive model peptides, AcAKGHEHQLE-NH2 and Ac-FGEHEHGRD-NH2 , were studied. Each of those had been rendered to type a range of thermodynamically steady complexes with copper(II) ions. All of the complexes had been stabilized, mainly due to interactions of metal with nitrogen and oxygen donor atoms, as well as rich hydrogen bond networks. It was also concluded that these complexes within the presence of hydrogen peroxide or DMPO Autophagy ascorbic acid can Ziritaxestat Metabolic Enzyme/Protease properly produce hydroxyl radicals and have an ability to cleave the DNA strands. Surprisingly, the second studied ligand at the micromolar concentration range causes general DNA degradation. Keyword phrases: porin protein P1; Fusobacterium nucleatum; copper(II) binding; DNA degradation; reactive oxygen species generation; NDMA decomposition1. Introduction Colorectal cancer (CRC) will be the third most typical cancer [1]. In spite of the progress made in terms of diagnosis and treatment approaches, it remains among the major causes of death amongst oncological sufferers (second location worldwide). Among the danger factors, unhealthy diet program, obesity, lack of physical activity, postmenopausal hormones, tobacco and alcohol are distinguished [2]. Furthermore, gut microbiota play an necessary part inside the carcinogenesis with the large intestine [3]. Correlations among the composition of human microbiota and CRC were initially announced within the 1970s. It was later reported that the existence of greater than a dozen bacterial species are associated having a larger threat of colon cancer [4,5]. In 2013, it was concluded that the Fusobacterium nucleatum increases neoplastic changes [6,7]. This anaerobic, Gram-negative bacterium is naturally present in human dental plaque. Even so, if it is actually present within the colon, it becomes a precursor to cancer. Interestingly, this bacterium is actively involved in cancer progression [8]. It has been reported that several F. nucleatum outer membrane proteins take aspect in cancerogenesis [94]. Furthermore, it was shown that fragments of FomA (F. nucleatum significant outer membrane protein), inside the presence of endogenous substances including hydrogen peroxide or antioxidants, e.g., ascorbic acid, induce cells to create reactive oxygen species (ROS), top to oxidative pressure. The effect is much more important inside the presence of Cu(II) ions, which form complexes with FomA [13]. The arising ROS can induce DNA damage and trigger redox-dependent transcription aspects. The precise mechanism that induces o.