通道孔口侧链大小影响P2X(2)受体的Ca(2+)阻断。

Size of side-chain at channel pore mouth affects Ca(2+) block of P2X(2) receptor.

作者信息

Nakazawa Ken, Sawa Hideaki, Ojima Hiloe, Ishii-Nozawa Reiko, Takeuchi Koichi, Ohno Yasuo

机构信息

Cellular and Molecular Pharmacology Section, National Institute of Health Sciences, 1-18-1 Kamiyoga, Segataya, Tokyo, 158-8501, Japan.

出版信息

Eur J Pharmacol. 2002 Aug 9;449(3):207-11. doi: 10.1016/s0014-2999(02)02001-0.

DOI:10.1016/s0014-2999(02)02001-0

PMID:12167461

Abstract

Effects of amino acid replacement at the channel pore mouth of P2X(2) receptor/channel on multivalent cation channel block were investigated. When Asn(333) was replaced with various amino acid residues with neutral side chains (Gly, Ala, Val, Leu and Ile), the block by Ca(2+) was attenuated according to the sizes of the side chains. The block by La(3+) was also greatest with the Gly-substituted mutant, but this preference was not found for the block by other multivalent cations tested. The side chain at the channel pore mouth may interfere with the access of Ca(2+) block by steric hindrance.

摘要

研究了P2X(2)受体/通道孔口处氨基酸替换对多价阳离子通道阻断的影响。当Asn(333)被具有中性侧链的各种氨基酸残基（甘氨酸、丙氨酸、缬氨酸、亮氨酸和异亮氨酸）取代时，Ca(2+)的阻断作用根据侧链大小而减弱。La(3+)的阻断作用在甘氨酸取代的突变体中也最大，但在其他测试的多价阳离子的阻断中未发现这种偏好。通道孔口处的侧链可能通过空间位阻干扰Ca(2+)的阻断作用。