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PHOTOHEMOLYSIS OF HUMAN ERYTHROCYTES LABELED IN BAND 3 WITH EOSIN‐ISOTHIOCYANATE
Author(s) -
Pooler John P.,
Girotti Albert W.
Publication year - 1986
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 - 10.1111/j.1751-1097.1986.tb04698.x
Subject(s) - band 3 , eosin , phototoxicity , chemistry , dids , eosin y , absorbance , fluorescence , lysis , membrane , hemolysis , singlet oxygen , biophysics , photochemistry , chromatography , biochemistry , oxygen , staining , in vitro , membrane protein , biology , organic chemistry , physics , photocatalysis , genetics , catalysis , quantum mechanics , immunology
Eosin‐isothiocyanate (EYNCS) is 50 to 100 times more effective in sensitizing delayed photo‐hemolysis of human erythrocytes than is eosin when matched for absorbance in the reaction medium. These dyes are equally efficient in generating singlet oxygen, a potent membrane oxidant. When cells are treated with sensitizer and washed extensively prior to illumination, EYNCS phototoxicity persists, while that of eosin is lost. SDS‐gel electrophoresis of membranes from EYNCS‐exposed cells shows a large fluorescence signal coincident with band 3 protein that is abolished by pretreatment with H 2 DIDS, the inhibitor of anion exchange by band 3. This treatment reduces the photohemolytic potency of EYNCS by over 90%. The marked enhancement of photohemolytic activity upon binding sensitizer to band 3 implicates band 3 itself as a site of photodamage leading to lysis.