0000000000292709
AUTHOR
Slawomir Potocki
showing 6 related works from this author
Sometimes less is more—the impact of the number of His residues on the stability of Zn(ii)–SmtB and BigR4 α-5 domain complexes
2021
The increasing number of antibiotic-resistant pathogens has become one of the major health problems of modern times, including infections caused by Mycobacterium tuberculosis. One of the possible mammalian immune system responses to mycobacterial infection is the increase of the zinc(II) concentration in phagosomes to a toxic level. The mycobacterial SmtB protein belongs to the family of ArsR/SmtB transcription regulators. In the presence of high concentrations of metals, SmtB dissociates from DNA and activates the expression of metal efflux proteins. In this work, we focus on the α5 zinc(II) binding domains of SmtB/BigR4 proteins (the latter being the SmtB homolog from non-pathogenic M. sm…
Pneumococcal HxxHxH triad – Copper(II) interactions – How important is the ‘x’?
2019
Abstract PhtA, a Streptococcus pneumoniae polyhistidine triad protein, which contributes to virulence by interacting with components of the immune system, by being involved in adherence of bacteria and in Zn(II) uptake, contains five copies of the HxxHxH sequence. Since this motif is also present in numerous Cu(II) binding proteins, we decided to focus on the bioinorganic chemistry of copper(II) with three of such PhtA repeats, in order to understand which of the PhtA triads binds Cu(II) with the highest affinity and explain if Cu(II) would be able to outcompete Zn(II) from its native binding site under physiological metal concentrations.
Pneumococcal histidine triads – involved not only in Zn2+, but also Ni2+ binding?
2018
Polyhistidine triad proteins, which participate in Zn2+ uptake in Streptococcus pneumoniae, contain multiple copies of the HxxHxH (histidine triad motif) sequence. We focus on three such motifs from one of the most common and well-conserved polyhistidine triad proteins, PhtA, in order to understand their bioinorganic chemistry; particular focus is given to (i) understanding which of the PhtA triads binds Zn2+ with the highest affinity (and why) and (ii) explaining whether Ni2+ (also crucial for bacterial survival and virulence) could potentially outcompete Zn2+ at its native binding site. There is no significant difference in the stability of zinc(II) complexes with the three studied protei…
Zinc(II)—The Overlooked Éminence Grise of Chloroquine’s Fight against COVID-19?
2020
The authors would like to thank Agnieszka Michalczuk for providing us with her artistic vision of SARS-CoV-2.
Zn(II) and Ni(II) complexes with poly-histidyl peptides derived from a snake venom
2018
Abstract The snake venoms are complex mixtures containing many bioactive peptides and proteins; some of them are aimed to protect the snake glands, where the venom is stored, until the latter is inoculated in the victim. In the venom of some vipers of the genus Atheris , a set of peptides containing poly-His and poly-Gly segments was recently found. Poly-His peptides are not rare in Nature. Although their exact biological function is most often unknown, one thing is certain: they have good binding properties towards the transition metal ions. As a matter of fact, the imidazole side chain of histidine is one of the groups most frequently involved in metal complexation in the active sites of …
Triplet of cysteines – Coordinational riddle?
2020
Polythiol binding of metal ions plays crucial role in the proper functioning of cysteine-rich proteins that are responsible for metal homeostasis and defending processes against metal toxicity (including heavy metals detoxification). The coordination properties of cysteine residues involved in specific sequencional patterns in proteins (like those present in e.g. metallothioneins) are interesting not only from a chemical point of view but may also lead to a better understanding of the purpose and allocation of metal ions in various biomolecules. In this study, the interaction of Zn2+, Cd2+ and Ni2+ ions with four peptides containing cysteine triplet motif were studied by potentiometric and …