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001-es BibID:	BIBFORM004855
Első szerző:	Bagdány Miklós
Cím:	Anuroctoxin, a new scorpion toxin of the alpha-KTx 6 subfamily, is highly selective for Kv1.3 over IKCa1 ion channels of human T lymphocytes / Bagdany, M., Batista, C. V. F., Valdez-Cruz, N. A., Somodi, S., Rodriguez de la Vega, R. C., Licea, A. F., Varga, Z., Gaspar, R., Possani, L. D., Panyi, G.
Dátum:	2005
Megjegyzések:	The physiological function of T lymphocytes can be modulated selectively by peptide toxins acting on Kv1.3 K(+) channels. Because Kv1.3-specific peptide toxins are considered to have a significant therapeutic potential in the treatment of autoimmune diseases, the discovery of new toxins is highly motivated. Through chromatographic procedures and electrophysiological assays, using patch-clamp methodology, the isolation of a novel peptide named anuroctoxin was accomplished using the venom of the Mexican scorpion Anuroctonus phaiodactylus. It has 35 amino acid residues with a molecular weight of 4082.8, tightly bound by four disulfide bridges whose complete covalent structure was determined. It has a pyroglutamic acid at the N-terminal region and an amidated C-terminal residue. Sequence comparison and phylogenetic clustering analysis classifies anuroctoxin into subfamily 6 of the alpha-KTx scorpion toxins (systematic name, alpha-KTx 6.12). Patch-clamp experiments show that anuroctoxin is a high-affinity blocker of Kv1.3 channels of human T lymphocytes with a K(d) of 0.73 nM, and it does not block the Ca(2+)-activated IKCa1 K(+) channels. These two channels play different but important roles in T-lymphocyte activation. Furthermore, the toxin practically does not inhibit Shaker IR, mKv1.1, and rKv2.1 channels, whereas the affinity of anuroctoxin for hKv1.2 is almost an order of magnitude smaller than for Kv1.3. The pharmacological profile and the selectivity of this new toxin for Kv1.3 over IKCa1 may provide an important tool for the modulation of the immune system, especially in cases in which selective inhibition of Kv1.3 is required.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Animals antagonists & inhibitors Autoimmune Diseases Biophysics chemistry drug effects Human Humans Hungary Immune System Intermediate-Conductance Calcium-Activated Potassium Channels Ion Channels isolation & purification Kv1.3 Potassium Channel Lymphocytes Models,Molecular Molecular Weight pharmacology Phylogeny Potassium Potassium Channel Blockers Potassium Channels Potassium Channels,Calcium-Activated Potassium Channels,Voltage-Gated Research Scorpion Venoms Sequence Alignment Support T-Lymphocytes Toxins Toxins,Biological
Megjelenés:	Molecular Pharmacology. - 67 : 4 (2005), p. 1034-1044. -
További szerzők:	Batista, Cesar V. F. Valdez-Cruz, Norma A. Somodi Sándor (1977-) (belgyógyász) Rodriguez de la Vega, Ricardo C. Licea, Alexei F. Varga Zoltán (1969-) (biofizikus, szakfordító) Gáspár Rezső (1944-) (biofizikus) Possani, Lourival Domingos Panyi György (1966-) (biofizikus)
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001-es BibID:	BIBFORM006036
Első szerző:	Gáspár Rezső (biofizikus)
Cím:	Effects of bretylium tosylate on voltage-gated potassium channels in human T lymphocytes / Gaspar, R., Panyi, G., Ypey, D. L., Krasznai, Z., Vereb, G., Pieri, C., Damjanovich, S.
Dátum:	1994
Megjegyzések:	Using the patch-clamp technique, we determined that bretylium tosylate, a quaternary ammonium compound possessing immunomodulating activity, decreased the whole-cell K+ current in human T lymphocytes, in a dose-dependent manner, in the 0.05-5 mM extracellular concentration range. Bretylium tosylate prolonged the recovery from inactivation and accelerated the inactivation and deactivation of the K+ current but did not influence the kinetics of activation or the voltage dependence of activation and steady state inactivation of the K+ conductance. The percentage of drug-induced block was independent of membrane potential. K+ channel block by bretylium tosylate was partially and slowly removable by washing with drug-free extracellular solution. Bovine serum albumin (10 mg/ml) in the bath lifted the drug-induced block almost instantaneously, although not completely. In control experiments bovine serum albumin increased the inactivation time constant of the K+ channels but left the peak K+ current amplitude unaffected. On the basis of the experimental evidence, a gating-dependent allosteric interaction is suggested for the mechanism of drug action. The effective dose range, time of exposure, and reversibility of bretylium tosylate-induced K+ channel block correlated well with the same parameters of the drug-induced inhibition of T lymphocyte activation. The reported effects of bretylium tosylate on T cell mitogenesis can be regarded partly as a consequence of its blocking effects on voltage-gated K+ channels.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Bretylium Tosylate Cell Membrane drug effects Electrophysiology Human Hungary In Vitro Ion Channel Gating Kinetics Lymphocytes pharmacology physiology Potassium Potassium Channels Support,Non-U.S.Gov't T-Lymphocytes
Megjelenés:	Molecular pharmacology. - 46 : 4 (1994), p. 762-766. -
További szerzők:	Panyi György (1966-) (biofizikus) Ypey, Dirk L. Krasznai Zoltán (1950-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Pieri, Carlo Damjanovich Sándor (1936-2017) (biofizikus)
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001-es BibID:	BIBFORM052923
Első szerző:	Luna-Ramirez, Karen
Cím:	Structure, Molecular Modeling, and Function of the Novel Potassium Channel Blocker Urotoxin Isolated from the Venom of the Australian Scorpion Urodacus yaschenkoi / Karen Luna-Ramirez, Adam Bartok, Rita Restano-Cassulini, Veronica Quintero-Hernández, Fredy I. V. Coronas, Janni Christensen, Christine E. Wright, Gyorgy Panyi, Lourival D. Possani
Dátum:	2014
ISSN:	1521-0111
Megjegyzések:	This communication reports the structural and functional characterization of urotoxin, the first K(+) channel toxin isolated from the venom of the Australian scorpion Urodacus yaschenkoi. It is a basic peptide consisting of 37 amino acids with an amidated C-terminal residue. Urotoxin contains eight cysteines forming four disulfide bridges with sequence similarities resembling the ?-potassium channel toxin 6 (?-KTx-6) subfamily of peptides; it was assigned the systematic number of ?-KTx-6.21. Urotoxin is a potent blocker of human voltage-gated potassium channel (Kv)1.2 channels, with an IC50 of 160 pM, whereas its affinity for other channels tested was in the nanomolar range (hKv1.1, IC50 = 253 nM; hKv1.3, IC50 = 91 nM; and hKCa3.1, IC50 = 70 nM). The toxin had no effect on hKv1.4, hKv1.5, human ether-ℓa-go-go-related gene type 1 (hERG1), or human ether-ℓa-go-go-like (hELK2) channels. Multiple sequence alignments from the venom gland transcriptome showed the existence of four other new peptides similar to urotoxin. Computer modeling of urotoxin's three-dimensional structure suggests the presence of the ?/?-scaffold characteristic of other scorpion toxins, although very likely forming an uncommon disulfide pairing pattern. Using molecular dynamics, a model for the binding of this peptide to human Kv1.2 and hKv1.1 channels is presented, along with the binding of an in silico mutant urotoxin (Lys25Ala) to both channels. Urotoxin enriches our knowledge of K(+) channel toxins and, due to its high affinity for hKv1.2 channels, it may be a good candidate for the development of pharmacologic tools to study the physiologic functions of K(+) channels or related channelopathies and for restoring axonal conduction in demyelinated axons.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban scorpion toxin potassium channel
Megjelenés:	Molecular Pharmacology. - 86 : 1 (2014), p. 28-41. -
További szerzők:	Bartók Ádám (1984-) (biotechnológus) Restano-Cassulini, Rita Quintero-Hernandez, Veronica Coronas, Fredy I. V. Christensen, Janni Wright, Christine E. Panyi György (1966-) (biofizikus) Possani, Lourival Domingos
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001-es BibID:	BIBFORM043018
035-os BibID:	PMID:22622363
Első szerző:	Varga Zoltán (biofizikus, szakfordító)
Cím:	Vm24, a natural immunosuppressive peptide, potently and selectively blocks Kv1.3 potassium channels of human T cells / Zoltan Varga, Georgina Gurrola-Briones, Ferenc Papp, Ricardo C. Rodríguez de la Vega, Gustavo Pedraza-Alva, Rajeev B. Tajhya, Rezso Gaspar, Luis Cardenas, Yvonne Rosenstein, Christine Beeton, Lourival D. Possani, Gyorgy Panyi
Dátum:	2012
Megjegyzések:	Blockade of Kv1.3 K(+) channels in T cells is a promising therapeutic approach for the treatment of autoimmune diseases such as multiple sclerosis and type 1 diabetes mellitus. Vm24 (alpha-KTx 23.1) is a novel 36-residue Kv1.3-specific peptide isolated from the venom of the scorpion Vaejovis mexicanus smithi. Vm24 inhibits Kv1.3 channels of human lymphocytes with high affinity (K(d) = 2.9 pM) and exhibits >1500-fold selectivity over other ion channels assayed. It inhibits the proliferation and Ca(2+) signaling of human T cells in vitro and reduces delayed-type hypersensitivity reactions in rats in vivo. Our results indicate that Vm24 has exceptional pharmacological properties that make it an excellent candidate for treatment of certain autoimmune diseases
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban article Autoimmune Diseases Biophysics cell biology Cells Human Hungary In Vitro Ion Channels Kv1.3 Potassium Channel lymphocyte Lymphocytes Multiple Sclerosis Potassium Potassium Channels Rats külföldön készült közlemény
Megjelenés:	Molecular Pharmacology. - 82 : 3 (2012), p. 372-382. -
További szerzők:	Gurrola-Briones, Georgina Papp Ferenc (1979-) (biofizikus) Rodríguez, Ricardo C. de la Vega Pedraza-Alva, Gustavo Tajhya, Rajeev B. Gáspár Rezső (1944-) (biofizikus) Cardenas, Luis Rosenstein, Yvonne Beeton, Christine Possani, Lourival Domingos Panyi György (1966-) (biofizikus)
Pályázati támogatás:	TÁMOP-4.2.2-08/1/2008-0019 TÁMOP TÁMOP-4.2.1/B-09/1/KONV-2010-007 TÁMOP TÁMOP-4.2.2-A-11/1/KONV-2012-0025 TÁMOP
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