IMPAIRMENT OF RED CELL MEMBRANE CYTOSKELETON BY PROTOPORPHYRIN‐IX: LIGHT AND DARK EFFECTS

Photochemistry and Photobiology - Tập 47 Số 5 - Trang 689-697 - 1988
N. Dadosh1, Nurith Shaklai1
1Sackler Institute of Molecular Medicine, Sackler Faculty of Medicine, University of Tel Aviv, Ramat Aviv 69978, Israel

Tóm tắt

Abstract— Membrane cytoskeletons were separated by use of TritonX–100 from freshly isolated red cells, fixed with glutaraldehyde and their morphology was followed by scanning electron microscopy. At 37°C and pH 6.5 cytoskeletons retained cell‐like shapes for at least 2 h, but at higher pH values, they lost stability after 30 min, appearing as amorphous protein material. Irradiation in the presence of1–20 μM protoporphyrin‐IX at pH 6.5 caused crosslinking of the proteins when organized as cytoskeletons, but not when separated. Scanning electron microscopy also revealed that the cytoskeletal proteins conserved their cell‐like shape even at pH values higher than 7.0. It was concluded that illumination in the presence of porphyrin causes membrane rigidity by crosslinking of the cytoskeletal proteins, and their sensitivity to crosslinking is the result of their mutual arrangement in the membrane. At concentrations higher than 100 μM protoporphyrin‐IX induced, even in the absence of light, the opposite effect, namely dissociation of the cytoskeletal proteins. The data suggest that the changes observed in this study provide an explanation for both dark and light induced injuries of red cells in porphyria disorders.

Từ khóa


Tài liệu tham khảo

10.1016/0024-3205(85)90312-1

10.1016/S0021-9258(17)43657-X

10.1159/000207731

10.1146/annurev.bi.54.070185.001421

10.1111/j.1751-1097.1985.tb03523.x

Cohen C. M., 1983, The molecular organization of the Red Cell membrane skeleton, Semin. Hematol., 20, 141

10.1007/978-1-4684-4406-3_24

10.1016/0005-2736(81)90420-X

10.1111/j.1751-1097.1978.tb07695.x

10.1016/0005-2736(78)90309-7

10.1016/0005-2736(80)90526-X

Falk J. E., 1964, Porphyrins and Metalloporphyrins, 263

10.1016/S0006-291X(76)80165-9

10.1172/JCI106884

Hayat M. A., 1978, Introduction to Biological Scanning Electron Microscopy, 91

Krach‐Hanser V., 1981, Molecular aspects of ligand binding to serum albumin, Pharmacol. Rev., 33, 17

10.1038/227680a0

10.1126/science.179.4078.1131

Lowry Q. H., 1951, Protein measurement with the pholin phenol reagent, J. Biol. Chem., 193, 265, 10.1016/S0021-9258(19)52451-6

10.1111/j.1432-1033.1984.tb08474.x

Palck J., 1983, Red cell membrane skeletal defects in hereditary and acquired hemolytic anemias, Semin. Hematol., 20, 189

10.1172/JCI108233

Rosenfeld M., 1950, Interaction between human serum albumin and ferriprotoporphyrin IX, J. Biol. Chem., 183, 663

10.1042/bj2140503

Shaklai N., 1986, Disintegration of red cell membrane by hemin, Biochem. Int., 13, 467

10.1016/0167-4838(87)90027-6

Sheetz M. P., 1980, 2,3‐Diphosphoglycerate and ATP dissociate erythrocyte membrane skeleton, J. Biol. Chem., 255, 9955, 10.1016/S0021-9258(18)43485-0

Taddeini L., 1968, The clinical porphyrias, Semin. Hematol, 5, 335

10.1016/0005-2736(81)90297-2