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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
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001-es BibID:	BIBFORM010358
Első szerző:	Papp Ferenc (biofizikus)
Cím:	Tst26, a novel peptide blocker of Kv1.2 and Kv1.3 channels from the venom of Tityus stigmurus / Papp, F., Batista, C. V. F., Varga, Z., Herceg, M., Roman-Gonzalez, S. A., Gaspar, R., Possani, L. D., Panyi, G.
Dátum:	2009
ISSN:	0041-0101 (Print)
Megjegyzések:	Using high-performance liquid chromatography Tst26, a novel potassium channel blocker peptide, was purified from the venom of the Brazilian scorpion Tityus stigmurus. its primary structure was determined by means of automatic Edman degradation and mass spectrometry analysis. The peptide is composed of 37 amino acid residues and tightly folded through three disulfide bridges, similar to other K+ channel blocking peptides purified from scorpion venoms. It contains the "essential dyad" for K+ channel recognition comprised of a lysine at position 27 and a tyrosine at position 36. Electrophysiological assays revealed that Tst26 blocked hKv1.2 and hKv1.3 channels with high affinity (K-d = 1.9 nM and 10.7 nM, respectively) while it did not affect several other ion channels (mKv1.1, hKv1.4, hKv1.5, hERG, hIKCa1, hBK, hNav1.5) tested at 10 nM concentration. The voltage-dependent steady-state parameters of K+ channel gating were unaffected by the toxin in both channels, but due to the fast association and dissociation kinetics Tst26 slowed the rate of inactivation of Kv1.3 channels. Based on the primary structure, the systematic nomenclature proposed for this peptide is alpha-KTx 4.6.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Chromatography Ion Channels Kinetics Lysine Mass Spectrometry Peptides Potassium Scorpion Venoms Spectrometry Tyrosine
Megjelenés:	Toxicon. - 54 : 4 (2009), p. 379-389. -
További szerzők:	Batista, Cesar V. F. Varga Zoltán (1969-) (biofizikus, szakfordító) Herceg Mónika (biofizikus) Roman-Gonzalez, Sergio A. Gáspár Rezső (1944-) (biofizikus) Possani, Lourival Domingos Panyi György (1966-) (biofizikus)
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