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001-es BibID:	BIBFORM076180
035-os BibID:	(cikkazonosító)e0204825 (WOS)000447417900013 (Scopus)85055079512
Első szerző:	Fizil Ádám (biológus)
Cím:	Calcium binding of the antifungal protein PAF: Structure, dynamics and function aspects by NMR and MD simulations / Ádám Fizil, Christoph Sonderegger, András Czajlik, Attila Fekete, István Komáromi, Dorottya Hajdu, Florentine Marx, Gyula Batta
Dátum:	2018
ISSN:	1932-6203
Megjegyzések:	Calcium ions (Ca2+) play an important role in the toxicity of the cysteine-rich and cationic antifungal protein PAF from Penicillium chrysogenum: high extracellular Ca2+ levels reduce the toxicity of PAF in the sensitive model fungus Neurospora crassa in a concentration dependent way. However, little is known about the mechanistic details of the Ca2+ ion impact and the Ca2+ binding capabilities of PAF outside the fungal cell, which might be the reason for the activity loss. Using nuclear magnetic resonance (NMR), isothermal titration calorimetry and molecular dynamics (MD) simulations we demonstrated that PAF weakly, but specifically binds Ca2+ ions. MD simulations of PAF predicted one major Ca2+ binding site at the C-terminus involving Asp53 and Asp55, while Asp19 was considered as putative Ca2+ binding site. The exchange of Asp19 to serine had little impact on the Ca2+ binding, however caused the loss of antifungal activity, as was shown in our recent study. Now we replaced the C-terminal aspartates and expressed the serine variant PAF{D53S/D55S}. The specific Ca2+ binding affinity of PAF{D53S/D55S} decreased significantly if compared to PAF, whereas the antifungal activity was retained. To understand more details of Ca2+ interactions, we investigated the NMR and MD structure/dynamics of the free and Ca2+-bound PAF and PAF{D53S/D55S}. Though we found some differences between these protein variants and the Ca2+ complexes, these effects cannot explain the observed Ca2+ influence. In conclusion, PAF binds Ca2+ ions selectively at the C-terminus; however, this Ca2+ binding does not seem to play a direct role in the previously documented modulation of the antifungal activity of PAF.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Plos One. - 13 : 10 (2018), p. 1-19. -
További szerzők:	Sonderegger, Christoph Czajlik András (1975-) (gyógyszerész) Fekete Attila (1983-) (vegyész) Komáromi István (1957-) (vegyész, molekuláris biológus, biokémikus) Hajdu Dorottya (1987-) (biológus) Marx, Florentine Batta Gyula (1953-) (molekula-szerkezet kutató)
Pályázati támogatás:	ANN 110821 OTKA TÁMOP-4.2.1/B-09/1/KONV-2010-0007 TÁMOP GINOP-2.3.2-15-2016-00008 GINOP GINOP-2.3.3-15-2016-00004 GINOP
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001-es BibID:	BIBFORM066897
035-os BibID:	(cikkazonosító)e0169920 (WOS)000391844200058 (Scopus)85009084271
Első szerző:	Sonderegger, Christoph
Cím:	D19S Mutation of the Cationic, Cysteine-Rich Protein PAF: Novel Insights into Its Structural Dynamics, Thermal Unfolding and Antifungal Function / Christoph Sonderegger, Ádám Fizil, Laura Burtscher, Dorottya Hajdu, Alberto Muñoz, Zoltán Gaáspári, Nick D. Read, Gyula Batta, Florentine Marx
Dátum:	2017
ISSN:	1932-6203
Megjegyzések:	The cysteine-rich, cationic, antifungal protein PAF is abundantly secreted into the culture supernatant of the filamentous Ascomycete Penicillium chrysogenum. The five ?-strands of PAF form a compact ?-barrel that is stabilized by three disulphide bonds. The folding of PAF allows the formation of four surface-exposed loops and distinct charged motifs on the protein surface that might regulate the interaction of PAF with the sensitive target fungus. The growth inhibitory activity of this highly stable protein against opportunistic fungal pathogens provides great potential in antifungal drug research. To understand its mode of action, we started to investigate the surface-exposed loops of PAF and replaced one aspartic acid at position 19 in loop 2 that is potentially involved in PAF active or binding site, with a serine (Asp19 to Ser19). We analysed the overall effects, such as unfolding, electrostatic changes, sporadic conformers and antifungal activity when substituting this specific amino acid to the fairly indifferent amino acid serine. Structural analyses revealed that the overall 3D solution structure is virtually identical with that of PAF. However, PAFD19S showed slightly increased dynamics and significant differences in the surface charge distribution. Thermal unfolding identified PAFD19S to be rather a two-state folder in contrast to the three-state folder PAF. Functional comparison of PAFD19S and PAF revealed that the exchange at residue 19 caused a dramatic loss of antifungal activity: the binding and internalization of PAFD19S by target cells was reduced and the protein failed to trigger an intracellular Ca2+ response, all of which are closely linked to the antifungal toxicity of PAF. We conclude that the negatively charged residue Asp19 in loop 2 is essential for full function of the cationic protein PAF.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Plos One. - 12 : 1 (2017), p. e0169920-1 - e0169920-21. -
További szerzők:	Fizil Ádám (1988-) (biológus) Burtscher, Laura Hajdu Dorottya (1987-) (biológus) Munoz, Alberto Gaáspári Zoltán Read, Nick D. Batta Gyula (1953-) (molekula-szerkezet kutató) Marx, Florentine
Pályázati támogatás:	ANN110821 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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