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Phage-Directed Synthesis of Photoluminescent Zinc Oxide Nanoparticles under Benign Conditions
No full textBiological systems, especially bacteriophages and peptides, are an attractive green alternative to other known methods of nanoparticle synthesis. In this work, for the first time, bacteriophages were employed to synthesize a specific peptide, capable of producing nanoparticles (NPs). Derivatives of M13 bacteriophage exposing a ZnO-binding peptide (TMGANLGLKWPV) on either pIII or pVIII phage coat protein were constructed and used as a biotemplate. The exposition of the ZnO-binding peptide, synthesized by phages during their propagation in bacteria, on M13 virions provided a groundwork for growing ZnO nanostructures. Depending on the recombinant phage type used (M13-pIII-ZnO or M13-pVIII-ZnO), well separated ZnO NPs or complex 3D structures of ZnO NPs of ca. 20-40 nm were synthesized at room temperature. The synthesized ZnO nanoparticles served as a luminescent material that emitted light near the short wavelength end of the visible region (at ca. 400 nm). The next very low intensity emission band at 530 nm demonstrated that the ZnO material obtained is characterized by a low concentration of surface defect
An Interplay of S-Nitrosylation and Metal Ion Binding for Astrocytic S100B Protein
Get PDFMammalian S100B protein plays multiple important roles in cellular brain processes. The protein is a clinically used marker for several pathologies including brain injury, neurodegeneration and cancer. High levels of S100B released by astrocytes in Down syndrome patients are responsible for reduced neurogenesis of neural progenitor cells and induction of cell death in neurons. Despite increasing understanding of S100B biology, there are still many questions concerning the detailed molecular mechanisms that determine specific activities of S100B. Elevated overexpression of S100B protein is often synchronized with
increased nitric oxide-related activity. In this work we show S100B is a target of exogenous S-nitrosylation in rat brain protein lysate and identify endogenous S-nitrosylation of S100B in a cellular model of astrocytes. Biochemical studies are presented indicating S-nitrosylation
tunes the conformation of S100B and modulates its Ca2+ and Zn2+ binding properties. Our in vitro results suggest that the possibility of endogenous S-nitrosylation should be
taken into account in the further studies of in vivo S100B protein activity, especially under conditions of increased NO-related activity
A short splicing isoform of HBS1L links the cytoplasmic exosome and SKI complexes in humans.
Get PDFThe exosome complex is a major eukaryotic exoribonuclease that requires the SKI complex for its activity in the cytoplasm. In yeast, the Ski7 protein links both complexes, whereas a functional equivalent of the Ski7 has remained unknown in the human genome.Proteomic analysis revealed that a previously uncharacterized short splicing isoform of HBS1L (HBS1LV3) is the long-sought factor linking the exosome and SKI complexes in humans. In contrast, the canonical HBS1L variant, HBS1LV1, which acts as a ribosome dissociation factor, does not associate with the exosome and instead interacts with the mRNA surveillance factor PELOTA. Interestingly, both HBS1LV1 and HBS1LV3 interact with the SKI complex and HBS1LV1 seems to antagonize SKI/exosome supercomplex formation. HBS1LV3 contains a unique C-terminal region of unknown structure, with a conserved RxxxFxxxL motif responsible for exosome binding and may interact with the exosome core subunit RRP43 in a way that resembles the association between Rrp6 RNase and Rrp43 in yeast. HBS1LV3 or the SKI complex helicase (SKI2W) depletion similarly affected the transcriptome, deregulating multiple genes. Furthermore, half-lives of representative upregulated mRNAs were increased, supporting the involvement of HBS1LV3 and SKI2W in the same mRNA degradation pathway, essential for transcriptome homeostasis in the cytoplasm
Draft Genome Sequence of Flavobacterium sp. 316, a Baltic Sea Isolate Exhibiting a High Level of Resistance to Marine Stress Conditions
Get PDFHere, we present the draft genome sequence of Flavobacterium sp. 316, isolated from brackish water of the Gulf of Gdansk, southern Baltic Sea. The assembly contains 3,971,755 bp in 17 scaffolds. The sequence will facilitate postgenomic studies on bacterial stress responses in the challenging habitat of the Baltic Sea
Prenyl Ammonium Salts – New Carriers for Gene Delivery: A B16-F10 Mouse Melanoma Model
Get PDFPurpose
Prenyl ammonium iodides (Amino-Prenols, APs), semi-synthetic polyprenol derivatives were studied as prospective novel gene transfer agents.
Methods
AP-7, -8, -11 and -15 (aminoprenols composed of 7, 8, 11 or 15 isoprene units, respectively)were examined for their capacity to form complexes with pDNA, for cytotoxicity and ability to transfect genes to cells.
Results
All the carriers were able to complex DNA. The highest, comparable to commercial reagents, transfection efficiency was observed for AP-15. Simultaneously, AP-15 exhibited the lowest negative impact on cell viability and proliferation—considerably lower than that of commercial agents. AP-15/DOPE complexes were also efficient to introduce pDNA to cells, without much effect on cell viability. Transfection with AP-15/DOPE complexes influenced the expression of a very few among 44 tested genes involved in cellular lipid metabolism. Furthermore, complexes containing AP-15 and therapeutic plasmid, encoding the TIMP metallopeptidase inhibitor 2 (TIMP2), introduced the TIMP2 gene with high efficiency to B16-F10 melanoma cells but not to B16-F10 melanoma tumors in C57BL/6 mice, as confirmed by
TIMP2 protein level determination.
Conclusion
Obtained results indicate that APs have a potential as non-viral vectors for cell transfection
Preliminary studies on the evolution of carbon assimilation abilities within Mucorales
Get PDFRepresentatives of Mucorales belong to one of the oldest lineages of terrestrial fungi. Although carbon is of fundamental importance for fungal growth and functioning, relatively little is known about enzymatic capacities of Mucorales. The evolutionary history and the variability of the capacity to metabolize different carbon sources among representatives of the order Mucorales was studied using Phenotypic Microarray Plates. The ability of 26 strains belonging to 23 nonpathogenic species of Mucorales to use 95 different carbon sources was tested. Intraspecies variability of carbon assimilation profiles was lower than interspecies variation for some selected strains. Although similarities between the phylogenetic tree and the dendrogram created from carbon source utilization data were observed, the ability of the various strains to use the analyzed substrates did not show a clear correlation with the evolutionary history of the group. Instead, carbon assimilation profiles are probably shaped by environmental conditions
Isoprenoid Alcohols are Susceptible to Oxidation with Singlet Oxygen and Hydroxyl Radicals.
Get PDFIsoprenoids, as common constituents of all living cells, are exposed to oxidative agents—reactive oxygen species, for example, singlet oxygen or hydroxyl radicals. Despite this fact, products of oxidation of polyisoprenoids have never been characterized. In this study, chemical oxidation of isoprenoid alcohols (Prenol-2 and -10) was performed using singlet oxygen (generated in the presence of hydrogen peroxide/molybdate or upon photochemical reaction in the presence of porphyrin), oxygen (formed upon hydrogen peroxide dismutation) or hydroxyl radical (generated by the hydrogen peroxide/sonication, UV/titanium dioxide or UV/hydrogen peroxide) systems. The structure of the obtained products, hydroxy-, peroxy- and
heterocyclic derivatives, was studied with the aid of mass
spectrometry (MS) and nuclear magnetic resonance (NMR)
methods. Furthermore, mass spectrometry with electrospray ionization appeared to be a useful analytical tool to detect the products of oxidation of isoprenoids (ESI–MS analysis), as well as to establish their structure on the basis of the fragmentation spectra of selected ions (ESI–MS/MS analysis). Taken together, susceptibility of polyisoprenoid alcohols to various oxidizing agents was shown for the first time
FAM46 proteins are novel eukaryotic non-canonical poly (A) polymerases
Get PDFFAM46 proteins, encoded in all known animal genomes, belong to the nucleotidyltransferase (NTase) fold superfamily. All four human FAM46 paralogs (FAM46A, FAM46B, FAM46C, FAM46D) are thought to be involved in several diseases, with FAM46C reported as a causal driver of multiple myeloma; however, their exact functions remain unknown. By using a combination of various bioinformatics analyses (e.g. domain architecture, cellular localization) and exhaustive literature and database searches (e.g. expression profiles, protein interactors), we classified FAM46 proteins as active non-canonical poly(A) polymerases, which modify cytosolic and/or nuclear RNA 3′ ends. These proteins may thus regulate gene expression and probably play a critical role during cell differentiation. A detailed analysis of sequence and structure diversity of known NTases possessing PAP/OAS1 SBD domain, combined with state-of-the-art comparative modelling, allowed us to identify potential active site residues responsible for catalysis and substrate binding. We also explored the role of single point mutations found in human cancers and propose that FAM46 genes may be involved in the development of other major malignancies including lung, colorectal, hepatocellular, head and neck, urothelial, endometrial and renal papillary carcinomas and melanoma. Identification of these novel enzymes taking part in RNA metabolism in eukaryotes may guide their further functional studies
In vitro antileukemic activity of novel adenosine derivatives bearing boron cluster modification
Get PDFA series of adenosine derivatives bearing a boron cluster were synthesized and evaluated for their cytotoxicity
against primary peripheral mononuclear cells from the blood of 17 patients with leukemias (16 CLL and 1 very rare PLL), as well as from 5 healthy donors used as a control. Among the tested agents, two, i.e., compounds 1 and 2, displayed high in vitro cytotoxicity and proapoptotic potential on leukemic cells, with only scarce activity being seen against control cells. Biological tests related to apoptosis revealed the
activation of the main execution apoptotic enzyme, procaspase-3, in CLL and PLL cells exposed to compounds
1 and 2. Moreover, the above compounds indicated high activity in the proteolysis of the apoptotic
markers PARP-1 and lamin B1, fragmentation of DNA, and the induction of some changes in the expression of the Mcl-1, protein apoptosis regulator in comparison with control cells
Concerted action of NIC relaxase and auxiliary protein MobC in RA3 plasmid conjugation
Get PDFConjugative transfer of the broad-host-range RA3
plasmid, the archetype of the IncU group, relies on
the relaxase NIC that belongs to the as yet uncharacterized
MOBP4 subfamily. NIC contains the signature
motifs of HUH relaxases involved in Tyr
nucleophilic attack. However, it differs in the residue
involved in His activation for cation coordination
and was shown here to have altered divalent
cation requirements. NIC is encoded in the mobCnic
operon preceded directly by oriT, where mobC
encodes an auxiliary transfer protein with a dual
function: autorepressor and stimulator of conjugative
transfer. Here an interplay between MobC and
NIC was demonstrated. MobC is required for efficient
NIC cleavage of oriT in supercoiled DNA
whereas NIC assists MobC in repression of the
mobC-nic operon. A 7-bp arm of IR3 (IR3a) was
identified as the binding site for NIC and the crucial
nucleotides in IR3a for NIC recognition were
defined. Fully active oriTRA3 was delineated to a 47-
bp DNA segment encompassing a conserved cleavage
site sequence, the NIC binding site IR3a and
the MobC binding site OM. This highly efficient RA3
conjugative system with defined requirements for
minimal oriT could find ample applications in biotechnology
and computational biology where simple
conjugative systems are needed