66 research outputs found
Molekuláris szenzorok vizsgálata és tervezése = Understanding and design of molecular sensors
Kutatásaink eredmĂ©nyei alapján tisztáztuk a konformáciĂłs dinamika szerepĂ©t fotoindukált elektrontranszfer szenzorokban. Ezek alapján arra a következtetĂ©sre jutottunk, hogy ezen szenzoroknál a hagyományos, kizárĂłlag az elektrondonor atomhoz törtĂ©nĹ‘ direkt koordináciĂłs hatáson kĂvűl egy másik hatás is Ă©rvĂ©nyesĂĽl a vendĂ©gmolekulák kötĹ‘dĂ©sekor. Ez pedig a komplexálĂłdás során bekövetkezĹ‘ konformáciĂłs hatások összessĂ©ge. Ezek alapján sikerĂĽlt olyan szenzorvegyĂĽleteket előállĂtanunk amelyek kĂĽlönösen Ă©rzĂ©kenyen reagálnak a konformáciĂłs változásokra ezáltal lehetĹ‘vĂ© tĂ©ve pl. a vendĂ©gmolekulák mĂ©rete alapján törtĂ©nĹ‘ szelekciĂłt. A munka során ezen kĂvĂĽl sikerrel valĂłsĂtottuk meg egy szenzorvegyĂĽlet kvarcfelĂĽletre valĂł kovalens rögzĂtĂ©sĂ©t, valamint ezen szenzor prototĂpussal a saxitoxin kimutatását. | Our studies revealed that the contribution of conformational dynamics to the signaling ability of PET type sensor molecules has a profound effect on the signaling potential of these sensors. Based on the obtained results we have implemented a new sensor design that uses the influence of conformational dynamics on the PET process and gives signals comparable or even greater than conventional sensors. A salient feature of this sensor class is their sensitivity towards the steric demand of the guests. Besides these results we have successfully modified covalently a pre-modified quartz surface with sensor molecules. With this sensor prototype we have managed to detect saxitoxin
Heterociklusos vegyületek átmenetifém-katalizált szintézise = Transition metal catalysed synthesis of heterocyclic compounds
Eljárást dolgoztunk ki nukleofil heterociklusos karbĂ©n (NHC) prekurzorkĂ©nt alkalmazhatĂł heterociklusos vegyĂĽletek moduláris szintĂ©zisĂ©re, amelyek közĂĽl több előállĂtását enantiomertiszta formában is elvĂ©geztĂĽk. ElőállĂtottunk több palladaciklusos katalizátort Ă©s rĂ©szletesen vizsgáltuk ezek szerkezete Ă©s aktivitása kapcsolatát keresztkapcsolási reakciĂłkban. BehatĂłan vizsgáltuk olyan Ăşj, palládiumkatalizált kapcsolási reakciĂłk lehetĹ‘sĂ©gĂ©t, amelyekben a fĂ©morganikus kapcsolĂłpartner fĂ©mrĂ©szletĂ©t szerves csoporttal tudjuk kiváltani. HatĂ©kony eljárást dolgoztunk ki benzo[b]tiofĂ©n-származĂ©kok Ă©s purinszármazĂ©kok ilyen Ăşton valĂł átalakĂtására. Vizsgáltuk az etinil-ciklohexanol, mint acetilĂ©nforrás alkalmazhatĂłságát diaril-acetilĂ©nek Ă©s benzofurán-származĂ©kok előállĂtásában. Ăšj palládiumkatalizált reakciĂłutat dolgoztunk ki benzofurán-származĂ©kok előállĂtására. Vizsgáltuk a piridazino[4,5-d]piridazin rendszeren poláris fĂ©morganikus reagensekkel kiválthatĂł reakciĂłt. TetrazinszármazĂ©kok Ă©s nukleofil karbĂ©nek reakciĂłját vizsgálva elsĹ‘kĂ©nt Ărtuk le kinoidális tetrazinvegyĂĽletek szintĂ©zisĂ©t. Sikeresen megvalĂłsĂtottuk több Ăşj tĂpusĂş fluoreszcens jelzĹ‘t hordozĂł makrociklus szintĂ©zisĂ©t Ă©s vizsgáltuk az inherens fluoreszcencia-letörĂ©st ezen rendszerekben, valamint alkalmazhatĂłságukat a molekuláris felismerĂ©sben. ElsĹ‘kĂ©nt Ărtunk le egy Ăşj, a konformáciĂłs dinamikán alapulĂł szenzorcsaládot. | We developed a new procedure for the preparation of nucleophilic heterocyclic carbene precursors and synthesized a series of chiral enantiopure NHCs. We prepared a series of palladacycles and studied the effect of their structure on their catalytic activity in cross coupling reactions. We studied such palladium catalysed processes where the organometallic coupling partner can be exchanged for an organic moiety. We developed an efficient transformation on benzo[b]thiophen and purine derivatives. We studied the use of 1-ethynyl-cyclohexanol as acetylene surrogate in the preparation of diarylacetylenes and benzofurane derivatives. We edeveloped a new palladium catalysed route for the synthesis of benzofurane derivatives. We studied the reactivity of pyridazino[4,5-d]pyridazines with polar organometallic reagents. We were the first to describe the synthesis of quinoidal tetrazine derivatives in the reaction of tetrazines with nucleophilic carbenes. We synthesized a series of macrocyclic heterocycles bearing different fluorescent markers and studied their inherent fluorescence quenching and their utility in molecular recognition. We were the first to described a new sensor family working on the principle of molecular dynamics
Fluoreszcensen jelölt mátrix metalloproteináz szubsztrátok szintézise = Synthesis of fluorescently labeled matrix metalloproteinase substrates
A tervezett munkával összhangban sikerĂĽlt előállĂtanunk olyan MMP-2 enzimszubsztrátokat amelyek lehetĹ‘sĂ©get adnak annak biokompatibilis jelölĂ©sĂ©re, FRET rendszerrĂ© alakĂtására. Az eredeti tervekkel ellentĂ©tben nem sikerĂĽlt oly mĂłdon kiviteleznĂĽnk a kettĹ‘s jelölĂ©st, hogy a peptidszekvenciába terminális acetilĂ©n Ă©s aril-jodid funkciĂłkat beĂ©pĂtve valĂłsĂtsuk meg a jelzĹ‘vegyĂĽletek egymás utáni bevitelĂ©t. Eredetileg Ăşgy terveztĂĽk, hogy a terminális acetilĂ©n klikk reakciĂłba vitele után az aril-jodidon Sonogashira reakciĂłval Ăşjabb acetilĂ©nt viszĂĽnk be ami lehetĹ‘sĂ©get teremt az Ăşjboli jelzĂ©s bevitelĂ©re. E stratĂ©gia sajnos a Sonogashira reakciĂł alacsony hozama miatt elvĂ©tetett. AlternatĂvakĂ©nt olyan peptidet állĂtottunk elĹ‘, mely terminális acetilĂ©n Ă©s ciklooktin csoportot is tartalmazott. MĂg ez utĂłbbi csoport rĂ©z hiányában is kĂ©pes az azidcsoportokkal reagálni a terminális acetilĂ©n ehhez rĂ©z(I) ionok jelenlĂ©tĂ©t igĂ©nyli. Ezzel az eljárással sikeresen valĂłsĂtottuk meg kĂ©t fluoreszcens jelzĹ‘vegyĂĽlet egymásutáni bevitelĂ©t nemcsak az enzimszubsztrátba de tetszĹ‘legesen választott fehĂ©rjĂ©be is, sĹ‘t lehetĹ‘sĂ©get adot arra is, hogy azidcsopotokkal mĂłdosĂtott, fluoreszcens szilika nanorĂ©szecskĂ©ket is alkalmazunk, mint fluoreszcens jelzĂ©s Ă©s hordozĂł egyben. A munka ezen rĂ©szĂ©n kĂvűl előállĂtottunk egy sor olyan klikk reakciĂłba vihetĹ‘ fluorofĂłrt amelyek emissziĂłs spektruma lefedi az egĂ©sz láthatĂł tartományt. EredmĂ©nyeinkrĹ‘l rangos folyĂłiratokban (pl Angewandte stb) Ă©s konferenciákon adtunk számot. | In accordance with the project proposal we have managed to synthesize an MMP-2 enzyme substrate that is capable to be transformed into FRET labeled system using fully biocompatible bioorthogonal modifications. Originally we have planned the introduction of clickable terminal acetylene moiety via incorporation of propargyl and aryl-halide containing amino acids in order to introduce the first label via click chemistry then using subsequent Sonogashira coupling strategy to introduce the second acetylene moiety to be capable of the second label. However this startegy have failed as the Sonogashira coupling resulted only low yields. Therefore an alternative strategy was explored where propargyl and cyclooctyne moiety was introduced into the octapeptide substrate sequence. Whilst the cyclooctyne moiety is capable of clicking with azido containing fluorophores without the need for copper catalyst the terminal acetylene function needs the metal catalyst. Using this strategy the sequential introduction of the two fluorescent label was successful. This startegy was demonstrated to be useful in dual labeling of enzymes as well. The dual nature of the enzyme substrate enabled us to use azide modified fluorescent silica nanoparticles as labels and support as well. Besides these studies a series of clickable fluorophores that practically cover the whole visible spectrum was developed. Our results have been published in high impact journals (eg Angewandte etc.) and on related conferences
Bioorthogonal fluorescent labels: a review on combined forces
This review ventures to summarize the latest developments in
bioorthogonal fluorescent imaging labels with a special focus
on bioimaging applications. We briefly summarize the most
preferred means of bioorthogonal tagging schemes for the
labeling of specific biomolecular structures. The review is
structured by the type of the fluorescent labels that can
address the problems that most commonly compromise
fluorescent imaging techniques, i.e. the autofluorescence of
biomolecules, the background fluorescence of unreacted
reagents, and photobleaching. Thus, we present (i) far-
red/near-infra-red emitting dyes, (ii) fluorogenic scaffolds,
and (iii) nanoparticle-based signaling platforms
Bioorthogonal Double-Fluorogenic Siliconrhodamine Probes for Intracellular Superresolution Microscopy
A series of double-fluorogenic siliconrhodamine probes were
synthesized. These tetrazine-functionalized, membrane-permeable
labels allowed site-specific bioorthogonal tagging of genetically
manipulated intracellular proteins and subsequent imaging using
super-resolution microscopy
The potential use of the Penicillium chrysogenum antifungal protein PAF, the designed variant PAFopt and its Îł-core peptide PÎłopt 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 Îł-core motif was modified to increase antifungal activity. In the present study, we report for the first time that Îł-core modulation influences the antifungal spectrum and efficacy of PAF against important plant pathogenic ascomycetes, and the synthetic Îł-core peptide PÎłopt , 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
Cloning and characterization of a novel functional organic anion transporting polypeptide 3A1 isoform highly expressed in the human brain and testis
Organic anion transporting polypeptide 3A1 (OATP3A1, encoded by the SLCO3A1 gene) is a prostaglandin, oligopeptide, and steroid/thyroid hormone transporter with wide tissue distribution, expressed, e.g., in the human brain and testis. Although the physiological importance of OATP3A1 has not yet been clarified, based on its expression pattern, substrate recognition, and evolutionary conservation, OATP3A1 is a potential pharmacological target. Previously, two isoforms of OATP3A1, termed as V1 and V2, have been characterized. Here, we describe the cloning and functional characterization of a third isoform, OATP3A1_V3. The mRNA of isoform V3 is formed by alternative splicing and results in an OATP3A1 protein with an altered C-terminus compared to isoforms V1 and V2. Based on quantitative PCR, we demonstrate the widespread expression of SLCO3A1_V3 mRNA in human organs, with the highest expression in the brain and testis. By generation of an isoform V3-specific antibody and immunostaining, we show that the encoded protein is expressed in the human choroid plexus, neurons, and both germ and Sertoli cells of the testis. Moreover, we demonstrate that in contrast to isoform V1, OATP3A1_V3 localizes to the apical membrane of polarized MDCKII cells. Using HEK-293 cells engineered to overexpress OATP3A1_V3, we verify the protein’s functionality and identify dehydroepiandrosterone sulfate as a novel OATP3A1 substrate. Based on their distinct expression patterns but overlapping functions, OATP3A1 isoforms may contribute to transcellular (neuro)steroid transport in the central nervous system
Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligandindependent dimerization in Sf21 microsomal membranes using noncanonical amino acids
Synthesis and Evaluation of Nicotinic Acid Derived Tetrazines for Bioorthogonal Labeling
- …