紫膜BLM的光电位与非质子离子迁移

嵌入紫膜碎片的BLM系统在不同离子强度的介质中产生不同的光电位信号。本文通过在介质中加入离子载体或离子通道剂对紫膜的光电响应信号进行了系统的研究。结果表明:上述光电位信号的差异主要是由紫膜的非质子离子的迁移引起的。与紫膜的质子跨膜迁移相比,这种非质子离子迁移也是由光驱动的,随介质的离子强度的增强而显著增强,但它的迁移速率更快,且产生反向的光电位。用通常方法所获得的光电位信号主要是这两种迁移信号的迭加。三价阳离子(La~(3+))可使紫膜质子泵反向并能抑制质子的吸收,但它似乎并不参与紫膜的非质子离子迁移。

PHOTOPOTENTIALS AND NONPROTON ION TRANSLOCATION OF BLM CONTAINING PURPLE MEMBRANE FRAGMENTS

Purple Membrane fragments in planar Bilayer Lipid Membrane (BLM) can produce different photopotential signals with different ionic strengthes in the media. With a systematic study on the effects of ionophores and ion channel on the photopotential signals, this paper verified ike nonproton ion translocation in Purple Membrane. Compared with the prot(,n pumping, this nonproton ion translocation is also light-driven and increases with the ionic strength of the medium, but it develops a faster and negative photopotential. Trivalent cations such as La3+ can reverse the proton pump and inhibit the proton uptake, but it does not seem to take part in the nonproton ion translocations of the Puple Membrane.