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001-es BibID:	BIBFORM063758
Első szerző:	Olamendi-Portugal, Timoteo
Cím:	Isolation, chemical and functional characterization of several new K+-channel blocking peptides from the venom of the scorpion Centruroides tecomanus / Timoteo Olamendi-Portugal, Adam Bartok, Fernando Zamudio-Zuniga, Andras Balajthy, Baltazar Becerril, Gyorgy Panyi, Lourival D. Possani
Dátum:	2016
ISSN:	0041-0101
Megjegyzések:	AbstractSix new peptides were isolated from the venom of the Mexican scorpion Centruroides tecomanus; their primary structures were determined and the effects on ion channels were verified by patch-clamp experiments. Four are K(+)-channel blockers of the ?-KTx family, containing 32 to 39 amino acid residues, cross-linked by three disulfide bonds. They all block Kv1.2 in nanomolar concentrations and show various degree of selectivity over Kv1.1, Kv1.3, Shaker and KCa3.1 channels. One peptide has 42 amino acids cross-linked by four disulfides; it blocks ERG-channels and belongs to the ?-KTx family. The sixth peptide has only 32 amino acid residues, three disulfide bonds and has no effect on the ion-channels assayed. It also does not have antimicrobial activity. Systematic numbers were assigned (time of elution on HPLC): ?-KTx 10.4 (time 24.1); ?-KTx 2.15 (time 26.2); ?-KTx 2.16 (time 23.8); ?-KTx 2.17 (time 26.7) and ?-KTx 1.9 (elution time 29.6). A partial proteomic analysis of the short chain basic peptides of this venom, which elutes on carboxy-methyl-cellulose column fractionation, is included. The pharmacological properties of the peptides described in this study may provide valuable tools for understanding the structure-function relationship of K(+) channel blocking scorpion toxins.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Toxicon 115 (2016), p. 1-12. -
További szerzők:	Bartók Ádám (1984-) (biotechnológus) Zamudio, Fernando Z. Balajthy András (1988-) (általános orvos) Becerril, Baltazar Panyi György (1966-) (biofizikus) Possani, Lourival Domingos
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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:	BIBFORM114858
035-os BibID:	(cikkazonosító)506 (scopus)85168734722 (wos)001056214900001
Első szerző:	Shakeel, Kashmala
Cím:	Of Seven New K⁺ Channel Inhibitor Peptides of Centruroides bonito, α-KTx 2.24 Has a Picomolar Affinity for Kv1.2 / Shakeel Kashmala, Olamendi-Portugal Timoteo, Naseem Muhammad Umair, Becerril Baltazar, Zamudio Fernando Z., Delgado-Prudencio Gustavo, Possani Lourival Domingos, Panyi Gyorgy
Dátum:	2023
ISSN:	2072-6651
Megjegyzések:	Seven new peptides denominated CboK1 to CboK7 were isolated from the venom of the Mexican scorpion Centruroides bonito and their primary structures were determined. The molecular weights ranged between 3760.4 Da and 4357.9 Da, containing 32 to 39 amino acid residues with three putative disulfide bridges. The comparison of amino acid sequences with known potassium scorpion toxins (KTx) and phylogenetic analysis revealed that CboK1 (?-KTx 10.5) and CboK2 (?-KTx 10.6) belong to the ?-KTx 10.x subfamily, whereas CboK3 (?-KTx 2.22), CboK4 (?-KTx 2.23), CboK6 (?-KTx 2.21), and CboK7 (?-KTx 2.24) bear > 95% amino acid similarity with members of the ?-KTx 2.x subfamily, and CboK5 is identical to Ce3 toxin (?-KTx 2.10). Electrophysiological assays demonstrated that except CboK1, all six other peptides blocked the Kv1.2 channel with Kd values in the picomolar range (24?763 pM) and inhibited the Kv1.3 channel with comparatively less potency (Kd values between 20?171 nM). CboK3 and CboK4 inhibited less than 10% and CboK7 inhibited about 42% of Kv1.1 currents at 100 nM concentration. Among all, CboK7 showed out-standing affinity for Kv1.2 (Kd = 24 pM), as well as high selectivity over Kv1.3 (850-fold) and Kv1.1 (~6000-fold). These characteristics of CboK7 may provide a framework for developing tools to treat Kv1.2-related channelopathies.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk CboK Centruroides bonito scorpion toxin Kv1.2 Kv1.3 Kv1.2 channelopathies electrophysiology
Megjelenés:	Toxins. - 15 : 8 (2023), p. 1-20. -
További szerzők:	Olamendi-Portugal, Timoteo Naseem, Muhammad Umair (1993-) (biofizikus, molekuláris biológus) Becerril, Baltazar Zamudio, Fernando Z. Delgado-Prudencio, Gustavo Possani, Lourival Domingos Panyi György (1966-) (biofizikus)
Pályázati támogatás:	K143071 OTKA
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