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Block effect of capsaicin on hERG potassium currents is enhanced by S6 mutation at Y652.
Eur J Pharmacol. 2010 Mar 25; 630(1-3):1-9.EJ

Abstract

The objectives of this study were to investigate the inhibitory action of capsaicin on wild-type (WT) and mutation human ether-a-go-go-related gene (hERG) potassium channel currents (I(hERG)), and to determine whether mutations in the S6 region are significant for the inhibition of I(hERG) by capsaicin. The hERG channel (WT, Y652A and F656A) was expressed in Xenopus oocytes and studied using standard two-microelectrode voltage-clamp techniques. The results show that capsaicin blocks WT hERG in a concentration-dependent manner, with an IC(50) of 17.45microM and a negative shift in the steady-state inactivation curve. Characteristics of blockade were consistent with capsaicin causing components of block in both the closed and open channel states. However, mutating the Y652 residue to Ala enhances the blockade effect of capsaicin with an IC(50) of 4.11microM, whereas mutation of F656A does not significantly alter drug potency. Simultaneously, for Y652A, the steady-state activation parameter is shifted to a more positive value by 5mV and the inactivation parameter is shifted to a more negative value by -29mV in the presence of 25microM capsaicin. In conclusion, capsaicin blocks hERG channels by binding to both the closed and open channel states.Y652 was important as a molecular determinant of blockade. Mutation Y652A enhances the drug block, which may cause some patients to be particularly sensitive to capsaicin clinically.

Authors+Show Affiliations

Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and Technology, Wuhan, China.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

19903464

Citation

Xing, Junlian, et al. "Block Effect of Capsaicin On hERG Potassium Currents Is Enhanced By S6 Mutation at Y652." European Journal of Pharmacology, vol. 630, no. 1-3, 2010, pp. 1-9.
Xing J, Ma J, Zhang P, et al. Block effect of capsaicin on hERG potassium currents is enhanced by S6 mutation at Y652. Eur J Pharmacol. 2010;630(1-3):1-9.
Xing, J., Ma, J., Zhang, P., & Fan, X. (2010). Block effect of capsaicin on hERG potassium currents is enhanced by S6 mutation at Y652. European Journal of Pharmacology, 630(1-3), 1-9. https://doi.org/10.1016/j.ejphar.2009.11.009
Xing J, et al. Block Effect of Capsaicin On hERG Potassium Currents Is Enhanced By S6 Mutation at Y652. Eur J Pharmacol. 2010 Mar 25;630(1-3):1-9. PubMed PMID: 19903464.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Block effect of capsaicin on hERG potassium currents is enhanced by S6 mutation at Y652. AU - Xing,Junlian, AU - Ma,Jihua, AU - Zhang,Peihua, AU - Fan,Xinrong, Y1 - 2009/11/10/ PY - 2009/09/03/received PY - 2009/10/16/revised PY - 2009/11/03/accepted PY - 2009/11/12/entrez PY - 2009/11/12/pubmed PY - 2010/5/25/medline SP - 1 EP - 9 JF - European journal of pharmacology JO - Eur J Pharmacol VL - 630 IS - 1-3 N2 - The objectives of this study were to investigate the inhibitory action of capsaicin on wild-type (WT) and mutation human ether-a-go-go-related gene (hERG) potassium channel currents (I(hERG)), and to determine whether mutations in the S6 region are significant for the inhibition of I(hERG) by capsaicin. The hERG channel (WT, Y652A and F656A) was expressed in Xenopus oocytes and studied using standard two-microelectrode voltage-clamp techniques. The results show that capsaicin blocks WT hERG in a concentration-dependent manner, with an IC(50) of 17.45microM and a negative shift in the steady-state inactivation curve. Characteristics of blockade were consistent with capsaicin causing components of block in both the closed and open channel states. However, mutating the Y652 residue to Ala enhances the blockade effect of capsaicin with an IC(50) of 4.11microM, whereas mutation of F656A does not significantly alter drug potency. Simultaneously, for Y652A, the steady-state activation parameter is shifted to a more positive value by 5mV and the inactivation parameter is shifted to a more negative value by -29mV in the presence of 25microM capsaicin. In conclusion, capsaicin blocks hERG channels by binding to both the closed and open channel states.Y652 was important as a molecular determinant of blockade. Mutation Y652A enhances the drug block, which may cause some patients to be particularly sensitive to capsaicin clinically. SN - 1879-0712 UR - https://www.unboundmedicine.com/medline/citation/19903464/Block_effect_of_capsaicin_on_hERG_potassium_currents_is_enhanced_by_S6_mutation_at_Y652_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-2999(09)01003-6 DB - PRIME DP - Unbound Medicine ER -