Premium
Effects of Photoinduced Membrane Rigidification on the Lysosomal Permeability to Potassium Ions
Author(s) -
Zhong Yigang,
Zhang Guojiang,
Yang Lu,
Zheng YanZhen
Publication year - 2000
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2000)0710627eopmro2.0.co2
Subject(s) - chemistry , membrane , membrane fluidity , permeability (electromagnetism) , fluorescence anisotropy , biophysics , membrane permeability , methylene blue , membrane potential , photochemistry , biochemistry , biology , photocatalysis , catalysis
Mechanism for the photoinduced increase in the lysosomal K + permeability is still unknown. In this study, we investigated the effect of photodamage‐induced membrane rigidification on the lysosomal K + permeability by measuring the membrane potential with bis(3‐propyl‐5‐oxoisoxazol‐4‐yl)pentamethine oxonol and by monitoring proton leakage with p ‐nitrophenol. Membrane fluidity was measured by the steady‐state fluorescence anisotropy of 1,6‐diphenyl‐1,3,5‐hexatriene. Methylene blue–mediated photodamage to lysosomes decreased their membrane fluidity and increased their K + permeability. The photoinduced increase in the K + permeability can be reversed by fluidizing the rigidified lysosomal membranes with benzyl alcohol. The results suggest that the membrane rigidification induced by photodamage may increase lysosomal K + permeability. This conclusion is supported by the observation that rigidifying lysosomal membranes by the treatment with membrane rigidifier cholesteryl hemisuccinate also enhanced the lysosomal K + permeability.