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001-es BibID:	BIBFORM066284
035-os BibID:	(Cikkazonosító)31131 (WOS)000381028800001 (Scopus)84981237531
Első szerző:	Fineberg, Jeffrey D.
Cím:	Closed-state inactivation involving an internal gate in Kv4.1 channels modulates pore blockade by intracellular quaternary ammonium ions / Jeffrey D. Fineberg, Tibor G. Szanto, Gyorgy Panyi, Manuel Covarrubias
Dátum:	2016
ISSN:	2045-2322
Megjegyzések:	Voltage-gated K+ (Kv) channel activation depends on interactions between voltage sensors and an intracellular activation gate that controls access to a central pore cavity. Here, we hypothesize that this gate is additionally responsible for closed-state inactivation (CSI) in Kv4.x channels. These Kv channels undergo CSI by a mechanism that is still poorly understood. To test the hypothesis, we deduced the state of the Kv4.1 channel intracellular gate by exploiting the trap-door paradigm of pore blockade by internally applied quaternary ammonium (QA) ions exhibiting slow blocking kinetics and high-affinity for a blocking site. We found that inactivation gating seemingly traps benzyl-tributylammonium (bTBuA) when it enters the central pore cavity in the open state. However, bTBuA fails to block inactivated Kv4.1 channels, suggesting gated access involving an internal gate. In contrast, bTBuA blockade of a Shaker Kv channel that undergoes open-state P/C-type inactivation exhibits fast onset and recovery inconsistent with bTBuA trapping. Furthermore, the inactivated Shaker Kv channel is readily blocked by bTBuA. We conclude that Kv4.1 closed-state inactivation modulates pore blockade by QA ions in a manner that depends on the state of the internal activation gate.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Scientific Reports. - 6 (2016), p. 31131-. -
További szerzők:	Szántó Gábor Tibor (1980-) (vegyész) Panyi György (1966-) (biofizikus) Covarrubias, Manuel
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM106378
035-os BibID:	(cikkazonosító)22168 (WoS)000905026500053 (scopus)85144513741
Első szerző:	Shi, Naiqi
Cím:	Venom composition and pain-causing toxins of the Australian great carpenter bee Xylocopa aruana / Shi Naiqi, Szanto Tibor G., He Jia, Schroeder Christina I., Walker Andrew A., Deuis Jennifer R., Vetter Irina, Panyi György, King Glenn F., Robinson Samuel D.
Dátum:	2022
ISSN:	2045-2322
Megjegyzések:	Most species of bee are capable of delivering a defensive sting which is often painful. A solitary lifestyle is the ancestral state of bees and most extant species are solitary, but information on bee venoms comes predominantly from studies on eusocial species. In this study we investigated the venom composition of the Australian great carpenter bee, Xylocopa aruana Ritsema, 1876. We show that the venom is relatively simple, composed mainly of one small amphipathic peptide ( XYTX1- Xa1a), with lesser amounts of an apamin homologue ( XYTX2-Xa2a) and a venom phospholipase-A2 ( PLA2). XYTX1- Xa1a is homologous to, and shares a similar mode-of-action to melittin and the bombilitins, the major components of the venoms of the eusocial Apis mellifera (Western honeybee) and Bombus spp. (bumblebee), respectively. XYTX1- Xa1a and melittin directly activate mammalian sensory neurons and cause spontaneous pain behaviours in vivo, effects which are potentiated in the presence of venom PLA2. The apamin-like peptide XYTX2- Xa2a was a relatively weak blocker of small conductance calcium-activated potassium ( KCa) channels and, like A. mellifera apamin and mast cell-degranulating peptide, did not contribute to pain behaviours in mice. While the composition and mode-of-action of the venom of X. aruana are similar to that of A. mellifera, the greater potency, on mammalian sensory neurons, of the major pain-causing component in A. mellifera venom may represent an adaptation to the distinct defensive pressures on eusocial Apidae.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Scientific Reports. - 12 : 1 (2022), p. 1-13. -
További szerzők:	Szántó Gábor Tibor (1980-) (vegyész) He, Jia Schroeder, Christina I. Walker, Andrew A. Deuis, Jennifer R. Vetter, Irina Panyi György (1966-) (biofizikus) King, Glenn F. Robinson, Samuel D.
Pályázati támogatás:	K143071 OTKA K142612 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
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