Novel AlkB Dioxygenases—Alternative Models for In Silico and In Vivo Studies

Background: ALKBH proteins, the homologs of Escherichia coli AlkB dioxygenase, constitute a direct, single-protein repair system, protecting cellular DNA and RNA against the cytotoxic and mutagenic activity of alkylating agents, chemicals significantly contributing to tumor formation and used in cancer therapy. In silico analysis and in vivo studies have shown the existence of AlkB homologs in almost all organisms. Nine AlkB homologs (ALKBH1–8 and FTO) have been identified in humans. High ALKBH levels have been found to encourage tumor development, questioning the use of alkylating agents in chemotherapy. The aim of this work was to assign biological significance to multiple AlkB homologs by characterizing their activity in the repair of nucleic acids in prokaryotes and their subcellular localization in eukaryotes. Methodology and Findings: Bioinformatic analysis of protein sequence databases identified 1943 AlkB sequences with eight new AlkB subfamilies. Since Cyanobacteria and Arabidopsis thaliana contain multiple AlkB homologs, they were selected as model organisms for in vivo research. Using E. coli alkB2 mutant and plasmids expressing cyanobacterial AlkBs, we studied the repair of methyl methanesulfonate (MMS) and chloroacetaldehyde (CAA) induced lesions in ssDNA, ssRNA, and genomic DNA. On the basis of GFP fusions, we investigated the subcellular localization of ALKBHs in A. thaliana and established its mostly nucleo-cytoplasmic distribution. Some of the ALKBH proteins were found to change their localization upon MMS treatment. Conclusions: Our in vivo studies showed highly specific activity of cyanobacterial AlkB proteins towards lesions and nucleic acid type. Subcellular localization and translocation of ALKBHs in A. thaliana indicates a possible role for these proteins in the repair of alkyl lesions. We hypothesize that the multiplicity of ALKBHs is due to their involvement in the metabolism of nucleo-protein complexes; we find their repair by ALKBH proteins to be economical and effective alternative to degradation and de novo synthesis

Examination of Imprinting Process with Molsidomine as a Template

molecule

N-(2-Arylethyl)-2-methylprop-2-enamides as Versatile Reagents for Synthesis of Molecularly Imprinted Polymers

The paper describes the formation of six aromatic N-(2-arylethyl)-2-methylprop-2-enamides with various substituents in benzene ring, viz., 4-F, 4-Cl, 2,4-Cl2, 4-Br, 4-OMe, and 3,4-(OMe)2 from 2-arylethylamines and methacryloyl chloride in ethylene dichloride with high yields (46–94%). The structure of the compounds was confirmed by 1H NMR, 13C NMR, IR, and HR-MS. Those compounds were obtained to serve as functionalized templates for the fabrication of molecularly imprinted polymers followed by the hydrolysis of an amide linkage. In an exemplary experiment, the imprinted polymer was produced from N-(2-(4-bromophenyl)ethyl)-2-methylprop-2-enamide and divinylbenzene, acting as cross-linker. The hydrolysis of 2-(4-bromophenyl)ethyl residue proceeded and the characterization of material including SEM, EDS, 13C CP MAS NMR, and BET on various steps of preparation was carried out. The adsorption studies proved that there was a high affinity towards the target biomolecules tyramine and L-norepinephrine, with imprinting factors equal to 2.47 and 2.50, respectively, when compared to non-imprinted polymer synthesized from methacrylic acid and divinylbenzene only

Dopamine-imprinted polymers: Template-monomer interactions, analysis of template removal and application to solid phase extraction. Molecules 2007

Abstract: A dopamine-imprinted polymer (MIP) was prepared in aqueous methanol solution at 60 o C by free-radical cross-linking polymerization of methacrylic acid in the presence of ethylene glycol dimethacrylate as the cross-linker and dopamine hydrochloride as the template molecule. Its ability to isolate dopamine was evaluated as the basis of a solid phase extraction procedure and compared with that of a non-imprinted polymer (NIP). The binding of dopamine was 84.1 % and 29.1 % for MIP and NIP, respectively. Various reported post-polymerization treatments to reduce template bleeding were examined. In our case the lowest bleeding was achieved after applying a combined procedure: continuous extraction in a Soxhlet apparatus (CE), followed by microwaveassisted extraction (ME) to a level of 0.061 μg/mL. A simplified model of the templatemonomer complexes allowed rationalization of monomer choice based on the heats of complex formation at a PM3 level of theory

Correction: Pollen morphology and variability of Polish native species from genus Salix L.

[This corrects the article DOI: 10.1371/journal.pone.0243993.]

Pollen morphology and variability of Polish native species from genus Salix L.

The pollen morphology was studied of 24 Salix species native to Poland, which represented two subgenera, 17 sections and five subsections occurring in Poland. The aim of this study was to discover the taxonomical usefulness of the pollen features under analysis, and to investigate the ranges of their interspecific variability. In total, 720 pollen grains were studied. They were analysed with respect to seven quantitative features (length of the polar axis - P, equatorial diameter - E, length of the ectoaperture - Le, exine thickness - Ex, and P/E, Ex/P and Le/P ratios) and the following qualitative ones: pollen outline and exine ornamentation. The most important features were exine ornamentation (muri, lumina and margo) characters. The pollen features should be treated as auxiliary because they allowed to distinguish eight individual Salix species, and five groups of species. Statistical analysis of the studied traits indicated a high variability among the tested species. The most variable biometric features were P, E and Le, while lower variability occurred in P/E, Le/P and d/E