Találati lista | Tudóstér

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)
Internet cím:	elektronikus változat DOI elektronikus változat
Borító:
Saját polcon:

001-es BibID:	BIBFORM004881
Első szerző:	Olamendi-Portugal, Timoteo
Cím:	Novel alpha-KTx peptides from the venom of the scorpion Centruroides elegans selectively blockade Kv1.3 over IKCa1 K+ channels of T cells / Olamendi-Portugal, T., Somodi, S., Fernandez, J. A., Zamudio, F. Z., Becerril, B., Varga, Z., Panyi, G., Gaspar, R., Possani, L. D.
Dátum:	2005
ISSN:	0041-0101
Megjegyzések:	From the venom of the Mexican scorpion Centruroides elegans Thorell five peptides were isolated to homogeneity by chromatographic procedures and their full amino acid sequence was determined by automatic Edman degradation. They all belong to the Noxiustoxin subfamily of scorpion toxins and were given the systematic names alpha-KTx 2.8 to 2.12, with trivial names Ce1 to Ce5, respectively. They have 39 amino acid residues, except for Ce3 which has only 38, but all of them have three disulfide bridges, and have molecular weights of 4255, 4267, 4249, 4295 and 4255 atomic mass units, respectively for Ce1 to Ce5. The C-terminal residues of Ce2, Ce4 and Ce5 were found to be amidated. The electrophysiological assay (whole-cell patch-clamp) showed that out of the five peptides, Ce1 (alpha-KTx 2.8), Ce2 (alpha-KTX2.9) and Ce4 (alpha-KTx 2.11) were effective blockers of Kv1.3 channels of human T lymphocytes, whereas these peptides did not inhibit the Ca2+-activated K+ channels (IKCa1) of the same cells. The equilibrium dissociation constants of these peptides for Kv1.3 were 0.70, 0.25 and 0.98nM for Ce1, Ce2 and Ce4, respectively. Furthermore, toxins Ce1, Ce2 and Ce4 practically did not inhibit the related voltage gated Shaker K+ channels, and rKv2.1 channels of the Shab family. The high affinity blockage of Kv1.3 channels by these peptides and their selectivity for Kv1.3 over IKCa1 may have significance in the development of novel tools for suppressing the function of those T cell subsets whose proliferation critically depends on the activity of Kv1.3 channels.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Amino Acid Sequence Animals antagonists & inhibitors Bayes Theorem Cell Line Cells chemistry Chromatography,High Pressure Liquid Comparative Study Electrophysiology Enzyme-Linked Immunosorbent Assay genetics Human Humans Intermediate-Conductance Calcium-Activated Potassium Channels Kv1.3 Potassium Channel Lymphocytes Mass Spectrometry metabolism Mexico Models,Genetic Molecular Sequence Data Molecular Weight Organophosphorus Compounds Peptides Phylogeny Potassium Potassium Channels Research Scorpion Venoms Scorpions Sequence Analysis,Protein Support T-Lymphocytes toxicity Toxins
Megjelenés:	Toxicon. - 46 : 4 (2005), p. 418-429. -
További szerzők:	Somodi Sándor (1977-) (belgyógyász) Fernandez, Juan Antonio Zamudio, Fernando Z. Becerril, Baltazar Varga Zoltán (1969-) (biofizikus, szakfordító) Panyi György (1966-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Possani, Lourival Domingos
Internet cím:	elektronikus változat DOI
Borító:
Saját polcon:

001-es BibID:	BIBFORM056042
Első szerző:	Varga Z.
Cím:	Anurotoxin : a potent and selective blocker of Kv1.3 channels / Varga Z., Valdez-Cruz N. A., Bagdany M., Somodi S., Gaspar R., Possani L. D. Panyi G.
Dátum:	2004
ISSN:	0006-3495
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idézhető absztrakt
Megjelenés:	Biophysical Journal. - 86 : 1 Suppl. 2 (2004), p. 538A. -
További szerzők:	Valdez-Cruz, Norma A. Bagdány Miklós Somodi Sándor (1977-) (belgyógyász) Gáspár Rezső (1944-) (biofizikus) Possani, Lourival Domingos Panyi György (1966-) (biofizikus)
Borító:
Saját polcon: