Tryptophan-dependent sensitized photoinactivation of colicin E1 channels in bilayer lipid membranes.
Tryptophan-dependent sensitized photoinactivation of colicin E1 channels in bilayer lipid membranes.
复制标题
双层脂膜中大肠菌素 E1 通道的色氨酸依赖性敏化光失活。
DOI：
10.1016/s0014-5793(01)02811-3
复制
发表时间：
2001
期刊：
影响因子：
3.5
通讯作者：
Cramer,WA
中科院分区：
文献类型：
--
作者：
Rokitskaya,TI;Zakharov,SD;Antonenko,YN;Kotova,EA;Cramer,WA
已知细菌毒素大肠杆菌素E1诱导跨平面双层脂质膜的电压门控电流。在本研究中，研究表明，在光敏剂铝酞菁的存在下照射膜后，大肠杆菌素诱导的电流大幅下降。这种效应几乎完全消除了单线态氧猝灭剂，叠氮化钠。使用单一色氨酸突变体大肠杆菌素E1，Trp 495被确定为负责大肠杆菌素通道活性的敏化光损伤的氨基酸残基。因此，一个特定的氨基酸残基在敏化光失活的一个确定的蛋白质功能的独特参与被证明。这表明，Trp 495是至关重要的大肠杆菌素通道结构域的易位和/或锚定在膜上。
The bacterial toxin colicin E1 is known to induce voltage-gated currents across a planar bilayer lipid membrane. In the present study, it is shown that the colicin-induced current decreased substantially upon illumination of the membrane in the presence of the photosensitizer, aluminum phthalocyanine. This effect was almost completely abolished by the singlet oxygen quencher, sodium azide. Using single tryptophan mutants of colicin E1, Trp495 was identified as the amino acid residue responsible for the sensitized photodamage of the colicin channel activity. Thus, the distinct participation of a specific amino acid residue in the sensitized photoinactivation of a defined protein function was demonstrated. It is suggested that Trp495 is critical for the translocation and/or anchoring of the colicin channel domain in the membrane.