Hard nut to crack: Solving the disulfide linkage pattern of the Neosartorya (Aspergillus) fischeri antifungal protein 2

As a consequence of the fast resistance spreading, a limited number of drugs are available to treat fungal infections. Therefore, there is an urgent need to develop new antifungal treatment strategies. The features of a disulfide bond-stabilized antifungal protein, NFAP2 secreted by the mold Neosartorya (Aspergillus) fischeri render it to be a promising template for future protein-based antifungal drug design, which requires knowledge about the native disulfide linkage pattern as it is one of the prerequisites for biological activity. However, in the lack of tryptic and chymotryptic proteolytic sites in the ACNCPNNCK sequence, the determination of the disulfide linkage pattern of NFAP2 is not easy with traditional mass spectrometry-based methods. According to in silico predictions working with a preliminary nuclear magnetic resonance (NMR) solution structure, two disulfide isomers of NFAP2 (abbacc and abbcac) were possible. Both were chemically synthesized; and comparative reversed-phase high-performance liquid chromatography, electronic circular dichroism and NMR spectroscopy analyses, and antifungal susceptibility and efficacy tests indicated that the abbcac is the native pattern. This knowledge allowed rational modification of NAFP2 to improve the antifungal efficacy and spectrum through the modulation of the evolutionarily conserved gamma-core region, which is responsible for the activity of several antimicrobial peptides. Disruption of the steric structure of NFAP2 upon gamma-core modification led to the conclusions that this motif may affect the formation of the biologically active three-dimensional structure, and that the gamma-core modulation is not an efficient tool to improve the antifungal efficacy or to change the antifungal spectrum of NFAP2

Doktori képzés 2.0: a hazai tudományos utánpótlás-nevelés verzióváltásának mezsgyéjén

A doktori képzés magyarországi rendszerében 2016-ban bekövetkezett változások alapvetően módosították az addigi paradigmát. Az időkényszer bevezetése (intenzifikálás), a képzési időszak első felét lezáró komplex vizsga szűrő, kizáró jellegének erősítése (szelektálás) és az ösztöndíjas helyek számának emelése (volumenizálás) a nemzetközi versenyképesség erősítését kívánták szorgalmazni. Annak ellenére, hogy ezen oktatáspolitikai intézkedések első eredményei csak két-három éven belül látnak majd napvilágot, az új típusú doktori képzés első négy évének tapasztalatai bőséges munícióval szolgálnak a hallgatói, oktatói értékelések vizsgálatára. A tanulmány a társadalomtudományi doktori képzések sorában élenjáró Budapesti Corvinus Egyetem doktori iskoláinak hallgatói és oktatói között lebonyolított kérdőíves vizsgálat alapján arra a kérdésre keresi a választ, hogy az érintett csoportok a megreformált tudományos utánpótlás-nevelés mely tényezőiben látják a minőség garanciáját

Two small, cysteine-rich and cationic antifungal proteins from Penicillium chrysogenum: A comparative study of PAF and PAFB

The filamentous fungus Penicillium chrysogenum Q176 secretes the antimicrobial proteins (AMPs) PAF and PAFB, which share a compact disulfide-bond mediated, β-fold structure rendering them highly stable. These two AMPs effectively inhibit the growth of human pathogenic fungi in micromolar concentrations and exhibit antiviral potential without causing cytotoxic effects on mammalian cells in vitro and in vivo. The antifungal mechanism of action of both AMPs is closely linked to - but not solely dependent on - the lipid composition of the fungal cell membrane and requires a strictly regulated protein uptake into the cell, indicating that PAF and PAFB are not canonical membrane active proteins. Variations in their antifungal spectrum and their killing dynamics point towards a divergent mode of action related to their physicochemical properties and surface charge distribution. In this review, we relate characteristic features of PAF and PAFB to the current knowledge about other AMPs of different sources. In addition, we present original data that have never been published before to substantiate our assumptions and provide evidences that help to explain and understand better the mechanistic function of PAF and PAFB. Finally, we underline the promising potential of PAF and PAFB as future antifungal therapeutics

The potential use of the Penicillium chrysogenum antifungal protein PAF, the designed variant PAFopt and its γ-core peptide Pγopt in plant protection.

The prevention of enormous crop losses caused by pesticide-resistant fungi is a serious challenge in agriculture. Application of alternative fungicides, such as antifungal proteins and peptides, provides a promising basis to overcome this problem; however, their direct use in fields suffers limitations, such as high cost of production, low stability, narrow antifungal spectrum and toxicity on plant or mammalian cells. Recently, we demonstrated that a Penicillium chrysogenum-based expression system provides a feasible tool for economic production of P. chrysogenum antifungal protein (PAF) and a rational designed variant (PAFopt ), in which the evolutionary conserved γ-core motif was modified to increase antifungal activity. In the present study, we report for the first time that γ-core modulation influences the antifungal spectrum and efficacy of PAF against important plant pathogenic ascomycetes, and the synthetic γ-core peptide Pγopt , a derivative of PAFopt , is antifungal active against these pathogens in vitro. Finally, we proved the protective potential of PAF against Botrytis cinerea infection in tomato plant leaves. The lack of any toxic effects on mammalian cells and plant seedlings, as well as the high tolerance to harsh environmental conditions and proteolytic degradation further strengthen our concept for applicability of these proteins and peptide in agriculture

Cavity Location by Muon Tomography

Muon tomography (or muography) is one of the most effective methods for locating unknown underground voids. If the geometric conditions are favorable for the measurements, no other geophysical method can compete with it, neither when resolution nor when simplicity is considered. In the last years, thanks to the continuous R&D of our low-cost, portable muon detectors, as well as the improved data processing methods, we have completed several successful natural and artificial cavity exploration projects, demonstrating that location is possible even if the characteristic size of cavity is 5% of the rock thickness between the detector and surface. Here we present case studies carried out in Hungarian underground sites, where we could find unknown cavities and verify the method by locating known artificial shafts and adits with high precision. Reaching these unknown caves is in progress either by conventional caving exploration techniques or by drilling. Further measurements are ongoing by the new upgraded detectors. By decreasing gas consumption and supporting electric power by solar cells, we are able to measure even at remote locations without the need of any direct access, for durations of several months

Transient detection capabilities of small satellite gamma-ray detectors

The new, small satellite-based gamma-ray detectors, like Cubesats Applied for MEasuring and Localizing Transients, will provide a new wa to detect gamma transients in the multimessenger era. The efficiency an the detection capabilities of such a system will be compared wit current missions, for example, Fermi Gamma-ray Burst Monitor (GBM). W used the Fermi GBM's observed short gamma-ray burst light curve aggregated from observed discrete detector event for the simulatio input. The corresponding direction-dependent detector response matrice were used to generate photon counts and light curves around a simulate event, enabling to determine the statistics. This method can be used i the future for trigger algorithm and detector system development, an also to estimate the efficiency of the data analysis pipeline regardin the observable gamma-ray bursts' parameters as well as othe electromagnetic transient

Multi-Wire Detectors for Underground Muography

The use of cosmic muons in imaging large artificial or geological structures started to flourish in the last decades, with the technological advancement in particle physics instrumentations. Muography became a most effective way to locate hidden density anomalies in geological structures, which includes revealing unknown parts of natural cave systems underneath the mountains. Our group has developed a series of gaseous multi-wire particle detectors for muography applications, with targets ranging from volcanology to speleology. Advancements in durability, power consumption, portability, and acquisition system have been proven via field measurements in natural sites besides extensive laboratory testing. The poster is dedicated to give details on the main requirements, components, and solutions which are means to transform standard particle detectors to be practically applicable in underground muography. We will present the expanded scale of experimental systems, targeting upgraded high-resolution tomography, hole-fit small-scale devices, and even economical simplified versions for exploratory measurements. These muography detectors could soon become effective novel tools in geo-sciences