Rokitskaya T I, Antonenko Y N, Kotova E A
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
FEBS Lett. 1993 Aug 30;329(3):332-5. doi: 10.1016/0014-5793(93)80248-s.
The effect of phthalocyanines, the potent photodynamic sensitizers, on the electric properties of the bilayer lipid membrane (BLM) is studied. It is shown, that tetrasulfonated, as well as trisulfonated, aluminium phthalocyanine do not alter the conductance of BLM, but elicit certain changes in the boundary potential difference, which points in favor of dye adsorption on BLM. Under the conditions of intense visible light irradiation, the phthalocyanines cause an increase in the conductance, resulting in the irreversible breakdown of BLM, formed from soy bean phosphatidylcholine, but fail to change the conductance of BLM, formed from diphytanoilphosphatidylcholine. The phthalocyanine-sensitized inactivation of gramicidin channels incorporated into BLM is observed under the conditions of weak visible light irradiation using an He-Ne laser. The photodynamic blockage of model ionic channels is considerably suppressed after oxygen depletion. The phenomenon consists of a marked reduction of a number of open channels, probably due to photomodification of tryptophan residues, essential for gramicidin functioning. The mechanism of the channel inactivation, involving the photosensitized reaction of the II type, and the relevance to the interaction of sensitizers with biomembranes, is discussed.
研究了强效光动力敏化剂酞菁对双层脂质膜（BLM）电学性质的影响。结果表明，四磺化铝酞菁以及三磺化铝酞菁不会改变BLM的电导，但会引起边界电位差的某些变化，这表明染料吸附在BLM上。在强可见光照射条件下，酞菁会导致电导增加，从而使由大豆磷脂酰胆碱形成的BLM发生不可逆破裂，但不会改变由二植烷酰磷脂酰胆碱形成的BLM的电导。在使用氦氖激光的弱可见光照射条件下，观察到掺入BLM中的短杆菌肽通道的酞菁敏化失活。耗氧后，模型离子通道的光动力阻断作用被显著抑制。该现象包括开放通道数量的显著减少，这可能是由于对短杆菌肽功能至关重要的色氨酸残基发生了光修饰。讨论了通道失活的机制，该机制涉及II型光敏反应以及敏化剂与生物膜相互作用的相关性。
