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001-es BibID:	BIBFORM076746
Első szerző:	Bozóki Beáta (molekuláris biológus)
Cím:	Use of Recombinant Fusion Proteins in a Fluorescent Protease Assay Platform and Their In-gel Renaturation / Bozóki Beáta, Mótyán János András, Miczi Márió, Gazda Lívia Diána, Tőzsér József
Dátum:	2019
ISSN:	1940-087X
Megjegyzések:	Proteases are intensively studied enzymes due to their essential roles in several biological pathways of living organisms and in pathogenesis; therefore, they are important drug targets. We have developed a magnetic-agarose-bead-based assay platform for the investigation of proteolytic activity, which is based on the use of recombinant fusion protein substrates. In order to demonstrate the use of this assay system, a protocol is presented on the example of human immunodeficiency virus type 1 (HIV-1) protease. The introduced assay platform can be utilized efficiently in the biochemical characterization of proteases, including enzyme activity measurements in mutagenesis, kinetic, inhibition, or specificity studies, and it may be suitable for high-throughput substrate screening or may be adapted to other proteolytic enzymes. In this assay system, the applied substrates contain N-terminal hexahistidine (His6) and maltose-binding protein (MBP) tags, cleavage sites for tobacco etch virus (TEV) and HIV-1 proteases, and a C-terminal fluorescent protein. The substrates can be efficiently produced in Escherichia coli cells and easily purified using nickel (Ni)-chelate-coated beads. During the assay, the proteolytic cleavage of bead-attached substrates leads to the release of fluorescent cleavage fragments, which can be measured by fluorimetry. Additionally, cleavage reactions can be analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A protocol for the in-gel renaturation of assay components is also described, as partial renaturation of fluorescent proteins enables their detection based on molecular weight and fluorescence.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban recombinant fusion protein substrate protease assay Ni-NTA magnetic agarose beads fluorescent protein in-gel renaturation human immunodeficiency virus type 1 protease
Megjelenés:	Journal of Visualized Experiments. - 143 (2019), p. 1-15. -
További szerzők:	Mótyán János András (1981-) (biokémikus, molekuláris biológus) Miczi Márió Gazda Lívia Diána (1989-) Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00044 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM072540
Első szerző:	Bozóki Beáta (molekuláris biológus)
Cím:	A recombinant fusion protein-based, fluorescent protease assay for high throughput-compatible substrate screening / Beáta Bozóki, Lívia Gazda, Ferenc Tóth, Márió Miczi, János András Mótyán, József Tőzsér
Dátum:	2018
ISSN:	0003-2697
Megjegyzések:	In connection with the intensive investigation of proteases, several methods have been developed for analysis of the substrate specificity. Due to the great number of proteases and the expected target molecules to be analyzed, time- and cost-efficient high-throughput screening (HTS) methods are preferred. Here we describe the development and application of a separation-based HTS-compatible fluorescent protease assay, which is based on the use of recombinant fusion proteins as substrates of proteases. The protein substrates used in this assay consists of N-terminal (hexahistidine and maltose binding protein) fusion tags, cleavage sequences of the tobacco etch virus (TEV) and HIV-1 proteases, and a C-terminal fluorescent protein (mApple or mTurquoise2). The assay is based on the fluorimetric detection of the fluorescent proteins, which are released from the magnetic bead-attached substrates by the proteolytic cleavage. The protease assay has been applied for activity measurements of TEV and HIV-1 proteases to test the suitability of the system for enzyme kinetic measurements, inhibition studies, and determination of pH optimum. We also found that denatured fluorescent proteins can be renatured after SDS-PAGE of denaturing conditions, but showed differences in their renaturation abilities. After in-gel renaturation both substrates and cleavage products can be identified by in-gel UV detection.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Analytical Biochemistry. - 540-541 (2018), p. 52-63. -
További szerzők:	Gazda Lívia Diána (1989-) Tóth Ferenc (1980-) (molekuláris biológus) Miczi Márió Mótyán János András (1981-) (biokémikus, molekuláris biológus) Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00044 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM082814
035-os BibID:	(cikkazonosító)e0227062 (WOS)000534341100013 (Scopus)85077691494
Első szerző:	Gazda Lívia Diána
Cím:	Biochemical characterization of Ty1 retrotransposon protease / Lívia Diána Gazda, Krisztina Joóné Matúz, Tibor Nagy, János András Mótyán, József Tőzsér
Dátum:	2020
ISSN:	1932-6203
Megjegyzések:	Ty1 is one of the many transposons in the budding yeast Saccharomyces cerevisiae. The life-cycle of Ty1 shows numerous similarities with that of retroviruses, e.g. the initially synthesized polyprotein precursor undergoes proteolytic processing by the protease. The retroviral proteases have become important targets of current antiretroviral therapies due to the critical role of the limited proteolysis of Gag-Pol polyprotein in the replication cycle and they therefore belong to the most well-studied enzymes. Comparative analyses of retroviral and retroviral-like proteases can help to explore the key similarities and differences which may help understanding how resistance is developed against protease inhibitors, but the available information about the structural and biochemical characteristics of retroviral-like, and especially retrotransposon, proteases is limited. To investigate the main characteristics of Ty1 retrotransposon protease of Saccharomyces cerevisiae, untagged and His6-tagged forms of Ty1 protease were expressed in E. coli. After purification of the recombinant proteins, activity measurements were performed using synthetic oligopeptide and fluorescent recombinant protein substrates, which represented the wild-type and the modified forms of naturally occurring cleavage sites of the protease. We investigated the dependence of enzyme activity on different reaction conditions (pH, temperature, ionic strength, and urea concentration), and determined enzyme kinetic parameters for the studied substrates. Inhibitory potentials of 10 different protease inhibitors were also tested. Ty1 protease was not inhibited by the inhibitors which have been designed against human immunodeficiency virus type 1 protease and are approved as antiretroviral therapeutics. A quaternary structure of homodimeric Ty1 protease was proposed based on homology modeling, and this structure was used to support interpretation of experimental results and to correlate some structural and biochemical characteristics with that of other retroviral proteases.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk retrotransposon Ty1 protease retrovirus homology modeling ty1 protease retroviral protease retrotransposon protease yeast biochemical characterization
Megjelenés:	Plos One. - 15 : 1 (2020), p. 1-24. -
További szerzők:	Matúz Krisztina (1980-) (vegyész, biokémikus) Nagy Tibor (1988-) (vegyész) Mótyán János András (1981-) (biokémikus, molekuláris biológus) Tőzsér József (1959-) (molekuláris biológus, biokémikus, vegyész)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00044 GINOP GINOP-2.3.3-15-2016-00021 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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