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Changes in the plasma membrane of yeast observed by spin label electron spin resonance and caused by photodynamic attack

✍ Scribed by J.M. Collins; G.E. Cohn; L.J. Lis


Publisher
Elsevier Science
Year
1982
Tongue
English
Weight
565 KB
Volume
30
Category
Article
ISSN
0009-3084

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✦ Synopsis


Spin label electron spin resonance (ESR) was used to characterize the response of lipid regions of the plasma membrane of yeast to photodynamic attack. Following photodynamic attack, the structure of these lipid regions changed resulting in the disappearance of an apparent order-disorder phase transition as well as impeding the diffusion of the steric acid based spin label 12NS into and across the plasma membrane. We propose that singlet molecular oxygen reacting with unsaturated carbon bonds in the fatty aeyl chains of lipid surrounding channel proteins leads to an increase in the order of the lipid array and/or a change in the channel protein's conformation and is the cause of the lethal effect of externally sensitized photodynamic action.