The gilled mushroom Agaricus crocodilinus (Agaricaceae) analyzed in this study hyperaccumulated Cd and showed common Zn and very low Mn concentrations. To gain an insight into the handling of heavy metals in this saprotrophic species, its two genes of the cation diffusion facilitator (CDF) protein family were isolated, AcCDF1 and AcCDF2, encoding the membrane transporters of the Zn-CDF and Mn-CDF subfamilies, respectively. When expressed in the model, metal-sensitive yeast, AcCDF1 conferred marked Zn tolerance and promoted the intracellular accumulation of Zn. Green fluorescent protein (GFP) tagging of AcCDF1 visualized the functional protein predominantly in the tonoplast, indicating that AcCDF1 can mediate the transport of Zn into vacuoles, which are used for deposition of excess Zn in most fungi. AcCDF2 conferred a high degree of Mn tolerance to model yeast, in which the transport-active AcCDF2:GFP fusion was localized to the plasma membrane, suggesting a role in Mn export and thus reduced Mn accumulation. Furthermore, the AcCDF2 gene appeared to be Mn-inducible in A. crocodilinus, suggesting an Mn efflux function of AcCDF2. Neither AcCDFs nor the mutant AcCDF1 variants constructed to mimic transmembrane tetrahedral Cd transport sites manifested appreciable Cd-related phenotypes in yeast models, and further efforts are needed to elucidate the mechanism underlying Cd hyperaccumulation in A. crocodilinus.
- Klíčová slova
- Agaricaceae, Cation diffusion facilitator, Manganese, Metal accumulation, Metal transport, Zinc,
- MeSH
- Agaricus * genetika metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- kadmium * metabolismus MeSH
- mangan metabolismus MeSH
- proteiny přenášející kationty genetika metabolismus MeSH
- zinek metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fungální proteiny MeSH
- kadmium * MeSH
- mangan MeSH
- proteiny přenášející kationty MeSH
- zinek MeSH
Modern drug formulations often require, besides the active drug molecule, auxiliaries to enhance their pharmacological properties. Tailor-made, biocompatible polymers covalently connected to the drug molecule can fulfill this function by increasing its solubility, reducing its toxicity, and guiding it to a specific target. If targeting membrane-bound proteins, localization of the drug close to the cell membrane and its target is beneficial to increase drug efficiency and residence time. In this study, we present the synthesis of highly defined, branched polymeric structures with membrane-binding properties. One to three hydrophilic poly(ethylene oxide) or poly(2-ethyloxazoline) side chains were connected via a peptoid backbone using a two-step iterative protocol for solid-phase peptoid synthesis. Additional groups, e.g., a hydrophobic anchor for membrane attachment, were introduced. Due to the nature of solid-phase synthesis, the number and order of the side chains and additional units can be precisely defined. The method proved to be versatile for the generation of multifunctional, branched polymeric structures of molecular weights up to approximately 7000 g mol-1. The behavior of all compounds towards biological membranes and cells was investigated using liposomes as cell membrane models, HEK293 and U251-MG cell lines, and red blood cells, thereby demonstrating their potential value as drug auxiliaries with cell membrane affinity.
- Publikační typ
- časopisecké články MeSH
Bioactive moieties designed to bind to cell membrane receptors benefit from coupling with polymeric carriers that have enhanced affinity to the cell membrane. When bound to the cell surface, such carriers create a "2D solution" of a ligand with a significantly increased concentration near a membrane-bound receptor compared to a freely water-soluble ligand. Bifunctional polymeric carriers based on amphiphilic triblock copolymers were synthesized from 2-pent-4-ynyl oxazoline, 2-nonyl oxazoline and 2-ethyl oxazoline. Their self-assembly and interactions with plasma proteins and HEK 293 cells were studied in detail. The affinity of these triblock copolymers to HEK 293 cell membranes and organ tissues was tunable by the overall hydrophobicity of the polymer molecule, which is determined by the length of the hydrophobic and hydrophilic blocks. The circulation time and biodistribution of three representative triblock copolymers were monitored after intravenous administration to C57BL/6 albino mice. A prolonged circulation time was observed for polymers with longer hydrophobic blocks, despite their molecular weight being below the renal threshold.
- Klíčová slova
- Amphiphilic triblock polyoxazoline, Biodistribution in vivo, Blood proteins, Drug delivery, HEK 293 cells, Isothermal titration calorimetry,
- MeSH
- buněčná membrána MeSH
- cytoplazma MeSH
- HEK293 buňky MeSH
- hydrofobní a hydrofilní interakce MeSH
- lidé MeSH
- ligandy MeSH
- micely * MeSH
- myši MeSH
- polymery * chemie MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- ligandy MeSH
- micely * MeSH
- poly(2-oxazoline) MeSH Prohlížeč
- polymery * MeSH
