脂质双分子层膜的氢氧根离子通透性

Hydroxyl ion permeability of lipid bilayer membranes.

作者信息

Gutknecht J, Walter A

出版信息

Biochim Biophys Acta. 1981 Jul 6;645(1):161-2. doi: 10.1016/0005-2736(81)90525-3.

Abstract

The OH- permeability of lipid bilayer (egg phosphatidylcholine-cholesterol) membranes was estimated from ionic transference numbers and membrane conductances at high pH. Membranes are slightly cation (Na+) selective over the pH range of 6--10. However, at pH greater than 11, Na+ and Cl- conductances decrease and OH- conductance increases so that the membrane becomes highly selective to OH-. From the OH- conductance we estimate the OH- permeability coefficient to be 1.8 . 10(-9) cm . s-1. The OH- selectivity of lipid bilayers may contribute to the observed H+/OH- selectivity of some biological membrane at high pH.

摘要

通过离子迁移数和高pH值下的膜电导估算了脂质双层（卵磷脂 - 胆固醇）膜的OH⁻渗透性。在6 - 10的pH范围内，膜对阳离子（Na⁺）有轻微选择性。然而，在pH大于11时，Na⁺和Cl⁻电导降低，OH⁻电导增加，使得膜对OH⁻具有高度选择性。根据OH⁻电导，我们估算出OH⁻渗透系数为1.8×10⁻⁹ cm·s⁻¹。脂质双层的OH⁻选择性可能有助于解释在高pH值下某些生物膜所观察到的H⁺/OH⁻选择性。